• SpringBoot 读写分离（配Mysql5.7） 笔记

    目录

    需求

    环境

    数据库表字段

    操作笔记

    MyBatis自动生成mapper、xml的配置

    读写分离切换的代码实现

    入口主类代码

    创建WebAPI实现读主库、读从库、写主库

    验证读写分离

    拓展读写分离（写一个库，读多个库）

    需求

    有主从两个数据库（结构一致），期望在SpringBoot程序层面实现读写分离。

    具体需求：SpringBoot程序的写操作均进入主库；SpringBoot程序的读操作均访问从库。

    （这里为便于区分主从库，二者初始数据不一致，但结构完全一致）

    环境

    开发环境：win7 x64+IDEA2018

    java version ："1.8.0_111"

    mysql数据库版本5.7.10

    mysql主库：192.168.7.161:3306

    mysql从库：192.168.7.162:3306

    SpringBoot版本2.3.7

    数据库表字段

    数据库名：dbdemo

    数据表：categories和products;

    1. mysql> use dbdemo;
    2. Database changed
    3. mysql> show tables;
    4. +------------------+
    5. | Tables_in_dbdemo |
    6. +------------------+
    7. | categories       |
    8. | products         |
    9. +------------------+
    10. 2 rows in set (0.02 sec)
    11.  
    12. mysql> show create table categories;
    13. +------------+--------------------------------------------------------------------------------------------------------------------------------------------------
    14. --------------------------------------------------------------------------------------------------------+
    15. | Table      | Create Table
    16.                                                                                                         |
    17. +------------+--------------------------------------------------------------------------------------------------------------------------------------------------
    18. --------------------------------------------------------------------------------------------------------+
    19. | categories | CREATE TABLE `categories` (
    20.   `cat_id` int(11) NOT NULL AUTO_INCREMENT,
    21.   `cat_name` varchar(255) NOT NULL,
    22.   `cat_description` text,
    23.   `cat_date` datetime DEFAULT NULL,
    24.   PRIMARY KEY (`cat_id`)
    25. ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 |
    26. +------------+--------------------------------------------------------------------------------------------------------------------------------------------------
    27. --------------------------------------------------------------------------------------------------------+
    28. 1 row in set (0.23 sec)
    29.  
    30. mysql> show create table products;
    31. +----------+----------------------------------------------------------------------------------------------------------------------------------------------------
    32. ----------------------------------------------------------------------------------------------------------------------------------------------------------------
    33. -------------------------------------------------------------------------------------------------------------------------+
    34. | Table    | Create Table
    35.  
    36.                                                                                                                          |
    37. +----------+----------------------------------------------------------------------------------------------------------------------------------------------------
    38. ----------------------------------------------------------------------------------------------------------------------------------------------------------------
    39. -------------------------------------------------------------------------------------------------------------------------+
    40. | products | CREATE TABLE `products` (
    41.   `prd_id` int(11) NOT NULL AUTO_INCREMENT,
    42.   `prd_name` varchar(355) NOT NULL,
    43.   `prd_price` decimal(10,0) DEFAULT NULL,
    44.   `prd_date` datetime DEFAULT NULL,
    45.   `cat_id` int(11) NOT NULL,
    46.   PRIMARY KEY (`prd_id`),
    47.   KEY `fk_cat` (`cat_id`),
    48.   CONSTRAINT `products_ibfk_1` FOREIGN KEY (`cat_id`) REFERENCES `categories` (`cat_id`) ON UPDATE CASCADE
    49. ) ENGINE=InnoDB AUTO_INCREMENT=19 DEFAULT CHARSET=utf8 |
    50. +----------+----------------------------------------------------------------------------------------------------------------------------------------------------
    51. ----------------------------------------------------------------------------------------------------------------------------------------------------------------
    52. -------------------------------------------------------------------------------------------------------------------------+
    53. 1 row in set (0.09 sec)
    54.  
    55. mysql>

    操作笔记

    IDEA新建SpringBoot应用程序，添加了mybatis-generator-maven-plugin，jdbc，aop等依赖。

    基于切面和自定义注解实现了读写分离。

    项目结构如下

    完整pom.xm如下：

    1. "1.0" encoding="UTF-8"?>
    2. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    3.          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    4.     <modelVersion>4.0.0modelVersion>
    5.     <groupId>com.wdhgroupId>
    6.     <artifactId>springboot-read-write-split-mysqlartifactId>
    7.     <version>0.0.1-SNAPSHOTversion>
    8.     <name>springboot-read-write-split-mysqlname>
    9.     <description>Demo project for Spring Bootdescription>
    10.  
    11.     <properties>
    12.         <java.version>1.8java.version>
    13.         <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
    14.         <project.reporting.outputEncoding>UTF-8project.reporting.outputEncoding>
    15.         <spring-boot.version>2.3.7.RELEASEspring-boot.version>
    16.     properties>
    17.  
    18.     <dependencies>
    19.         <dependency>
    20.             <groupId>org.springframework.bootgroupId>
    21.             <artifactId>spring-boot-starter-webartifactId>
    22.         dependency>
    23.  
    24.         <dependency>
    25.             <groupId>org.projectlombokgroupId>
    26.             <artifactId>lombokartifactId>
    27.             <optional>trueoptional>
    28.         dependency>
    29.  
    30.         
    31.         <dependency>
    32.             <groupId>org.apache.commonsgroupId>
    33.             <artifactId>commons-lang3artifactId>
    34.         dependency>
    35.  
    36.         
    37.         <dependency>
    38.             <groupId>org.springframework.bootgroupId>
    39.             <artifactId>spring-boot-starter-aopartifactId>
    40.         dependency>
    41.  
    42.         <dependency>
    43.             <groupId>org.springframework.bootgroupId>
    44.             <artifactId>spring-boot-starter-data-jdbcartifactId>
    45.         dependency>
    46.  
    47.         <dependency>
    48.             <groupId>org.springframework.bootgroupId>
    49.             <artifactId>spring-boot-starter-jdbcartifactId>
    50.         dependency>
    51.  
    52.         <dependency>
    53.             <groupId>org.mybatis.spring.bootgroupId>
    54.             <artifactId>mybatis-spring-boot-starterartifactId>
    55.             <version>2.1.4version>
    56.         dependency>
    57.  
    58.         <dependency>
    59.             <groupId>mysqlgroupId>
    60.             <artifactId>mysql-connector-javaartifactId>
    61.             <version>8.0.22version>
    62.         dependency>
    63.  
    64.  
    65.  
    66.  
    67.  
    68.         <dependency>
    69.             <groupId>org.springframework.bootgroupId>
    70.             <artifactId>spring-boot-starter-testartifactId>
    71.             <scope>testscope>
    72.             <exclusions>
    73.                 <exclusion>
    74.                     <groupId>org.junit.vintagegroupId>
    75.                     <artifactId>junit-vintage-engineartifactId>
    76.                 exclusion>
    77.             exclusions>
    78.         dependency>
    79.     dependencies>
    80.  
    81.     <dependencyManagement>
    82.         <dependencies>
    83.             <dependency>
    84.                 <groupId>org.springframework.bootgroupId>
    85.                 <artifactId>spring-boot-dependenciesartifactId>
    86.                 <version>${spring-boot.version}version>
    87.                 <type>pomtype>
    88.                 <scope>importscope>
    89.             dependency>
    90.         dependencies>
    91.     dependencyManagement>
    92.  
    93.     <build>
    94.         <plugins>
    95.             <plugin>
    96.                 <groupId>org.apache.maven.pluginsgroupId>
    97.                 <artifactId>maven-compiler-pluginartifactId>
    98.                 <version>3.8.1version>
    99.                 <configuration>
    100.                     <source>1.8source>
    101.                     <target>1.8target>
    102.                     <encoding>UTF-8encoding>
    103.                 configuration>
    104.             plugin>
    105.             <plugin>
    106.                 <groupId>org.springframework.bootgroupId>
    107.                 <artifactId>spring-boot-maven-pluginartifactId>
    108.                 <version>2.3.7.RELEASEversion>
    109.                 <configuration>
    110.                     <mainClass>com.wdh.springbootreadwritesplitmysql.SpringbootReadWriteSplitMysqlApplication
    111.                     mainClass>
    112.                 configuration>
    113.                 <executions>
    114.                     <execution>
    115.                         <id>repackageid>
    116.                         <goals>
    117.                             <goal>repackagegoal>
    118.                         goals>
    119.                     execution>
    120.                 executions>
    121.             plugin>
    122.  
    123.             
    124.             
    125.             <plugin>
    126.                 <groupId>org.mybatis.generatorgroupId>
    127.                 <artifactId>mybatis-generator-maven-pluginartifactId>
    128.                 <version>1.3.1version>
    129.                 <configuration>
    130.                     <configurationFile>src\main\resources\mybatis-generator\generatorConfig.xmlconfigurationFile>
    131.                     <overwrite>falseoverwrite>
    132.                     <verbose>trueverbose>
    133.                 configuration>
    134.             plugin>
    135.  
    136.  
    137.         plugins>
    138.     build>
    139.  
    140. project>

    application.properties内容如下，配置了mysql主库和从库的连接信息

    1. # 应用名称
    2. spring.application.name=springboot-read-write-split-mysql
    3. # 应用服务 WEB 访问端口
    4. server.port=8080
    5.  
    6.  
    7. #这是自定义的mysql主数据库的访问配置
    8. spring.datasource.master.driver-class-name=com.mysql.cj.jdbc.Driver
    9. #以下是配合默认的spring.datasource.hikari的jdbcUrl
    10. spring.datasource.master.jdbcUrl=jdbc:mysql://192.168.7.161:3306/dbdemo?serverTimezone=UTC
    11. spring.datasource.master.username=root
    12. spring.datasource.master.[CSDN不让发]password[CSDN不让发]=XX你的密码XX
    13.  
    14. #这是自定义的mysql从数据库的访问配置
    15. spring.datasource.slave.driver-class-name=com.mysql.cj.jdbc.Driver
    16. spring.datasource.slave.jdbcUrl=jdbc:mysql://192.168.7.162:3306/dbdemo?serverTimezone=UTC
    17. spring.datasource.slave.username=root
    18. spring.datasource.slave.[CSDN不让发]password[CSDN不让发]=XX你的密码XX

    MyBatis自动生成mapper、xml的配置

    在src\main\resources下新建mybatis-generator目录及目录下generatorConfig.xml。

    src\main\resources\mybatis-generator\generatorConfig.xml

    前述pom.xml中的以下内容是指定使用此文件进行mybatis自动生成

    2.             
    3.             <plugin>
    4.                 <groupId>org.mybatis.generatorgroupId>
    5.                 <artifactId>mybatis-generator-maven-pluginartifactId>
    6.                 <version>1.3.1version>
    7.                 <configuration>
    8.                     <configurationFile>src\main\resources\mybatis-generator\generatorConfig.xmlconfigurationFile>
    9.                     <overwrite>falseoverwrite>
    10.                     <verbose>trueverbose>
    11.                 configuration>
    12.             plugin>

    generatorConfig.xml完整内容如下。（说明见注释）

    1. "1.0" encoding="UTF-8"?>
    2. generatorConfiguration
    3.         PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
    4.         "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
    6.  
    7. <generatorConfiguration>
    8.     
    9.     
    10.     
    11.     <classPathEntry location="D:\JavaDevEnv\maven_repository\Mysql\mysql-connector-java\8.0.22\mysql-connector-java-8.0.22.jar">classPathEntry>
    12.  
    13.     <context id="DB2Tables" targetRuntime="MyBatis3">
    14.         <commentGenerator>
    15.             <property name="suppressDate" value="false">property>
    16.             
    17.             <property name="suppressAllComments" value="false">property>
    18.         commentGenerator>
    19.  
    20.         
    21.         <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
    22.                         connectionURL="jdbc:mysql://localhost:3306/dbdemo?serverTimezone=UTC"
    23.                         userId="root"
    24.                         [CSDN不让发]password[CSDN不让发]="XX你的密码XX">
    25.         jdbcConnection>
    26.  
    27.         <javaTypeResolver >
    28.             <property name="forceBigDecimals" value="false" />
    29.         javaTypeResolver>
    30.  
    31.         
    32.         <javaModelGenerator targetPackage="com.wdh.springbootreadwritesplitmysql.entity" targetProject="src\main\java">
    33.             <property name="enableSubPackages" value="true" />
    34.             <property name="trimStrings" value="true" />
    35.         javaModelGenerator>
    36.  
    37.         
    38.         
    39.         
    40.         
    41.  
    42.         
    43.         
    44.         
    45.         
    46.  
    47.         
    48.         <sqlMapGenerator targetPackage="main.resources.mappers" targetProject="src">
    49.             <property name="enableSubPackages" value="true"/>
    50.         sqlMapGenerator>
    51.  
    52.         
    53.         <javaClientGenerator type="XMLMAPPER" targetPackage="com.wdh.springbootreadwritesplitmysql.mapper"  targetProject="src\main\java">
    54.             <property name="enableSubPackages" value="true" />
    55.         javaClientGenerator>
    56.  
    57.         
    58.         
    59.         
    60.         
    61.         
    62.         
    63.         
    64.         
    65.  
    66.         <table schema="dbdemo" tableName="categories"
    67.                enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"
    68.         >table>
    69.         <table schema="dbdemo" tableName="products"
    70.                enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"
    71.         >table>
    72.  
    73.     context>
    74. generatorConfiguration>

    注意，因主库和从库结构一致，上述配置文件中定义了按主库配置连接信息，访问并生成mapper和xml.

    配置完generatorConfig.xml后，在idea右侧Maven面板-本项目-Plugins-刷新-找到mybatis-generate-点击右键Run Maven Build即可生成代码。生成过程及日志见idea的控制台输出。

    （pom.xml中配置mybatis-generator后需要手动在idea的maven面板左上角点击刷新按钮才会在Plugins下显示mybatis-generator）

    执行之后将自动在【src\main\java\com\wdh\springbootreadwritesplitmysql\mapper】目录下生成【xx表名xxMapper.java】

    自动在【src\main\resources\mappers】目录下生成【xx表名xxMapper.xml】文件。

    读写分离切换的代码实现

    定义主从库枚举类型

    1. package com.wdh.springbootreadwritesplitmysql.enums;
    2.  
    3. /**
    4.  * @author WangDH
    5.  * @create 2022-11-10 13:51
    6.  *
    7.  * 数据源类型枚举
    8.  */
    9. public enum DBTypeEnum {
    10.     //数据库主库
    11.     MASTER,
    12.  
    13.     //数据库从库
    14.     SLAVE
    15. }

    定义DBContextHolder用于访问枚举和枚举变量记录切换，DBContextHolder.java代码如下

    1. package com.wdh.springbootreadwritesplitmysql.bean;
    2.  
    3. import com.wdh.springbootreadwritesplitmysql.enums.DBTypeEnum;
    4.  
    5. import java.util.concurrent.atomic.AtomicInteger;
    6.  
    7. /**
    8.  * @author WangDH
    9.  * @create 2022-11-10 13:59
    10.  */
    11. public class DBContextHolder {
    12.  
    13.     private static final ThreadLocal<DBTypeEnum> contextHolder=new ThreadLocal<>();
    14.  
    15.     private static final AtomicInteger counter=new AtomicInteger(-1);
    16.  
    17.     public static void set(DBTypeEnum dbTypeEnum){
    18.         contextHolder.set(dbTypeEnum);
    19.     }
    20.  
    21.     public static DBTypeEnum get(){
    22.         return contextHolder.get();
    23.     }
    24.  
    25.     public static void master(){
    26.         set(DBTypeEnum.MASTER);
    27.         System.out.println("切换到master");
    28.     }
    29.  
    30.     public static void slave(){
    31.         set(DBTypeEnum.SLAVE);
    32.         System.out.println("切换到slave");
    33.     }
    34.  
    35. }

    自定义MyRoutingDataSource实现AbstractRoutingDataSource，AbstractRoutingDataSource提供了程序运行时动态切换数据源的方法。MyRoutingDataSource.java代码如下。

    1. package com.wdh.springbootreadwritesplitmysql.bean;
    2.  
    3. import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
    4. import org.springframework.lang.Nullable;
    5.  
    6. /**
    7.  * @author WangDH
    8.  * @create 2022-11-10 13:57
    9.  */
    10. public class MyRoutingDataSource extends AbstractRoutingDataSource {
    11.  
    12.  
    13.     @Nullable
    14.     @Override
    15.     protected Object determineCurrentLookupKey() {
    16.         Object obj= DBContextHolder.get();
    17.         return obj;
    18.     }
    19. }

    定义DataSourceConfig数据源配置类初始化两个数据源和获取动态数据源。DataSourceConfig.java代码如下

    1. package com.wdh.springbootreadwritesplitmysql.config;
    2.  
    3. import com.wdh.springbootreadwritesplitmysql.bean.MyRoutingDataSource;
    4. import com.wdh.springbootreadwritesplitmysql.enums.DBTypeEnum;
    5. import org.springframework.beans.factory.annotation.Qualifier;
    6. import org.springframework.boot.context.properties.ConfigurationProperties;
    7. import org.springframework.boot.jdbc.DataSourceBuilder;
    8. import org.springframework.context.annotation.Bean;
    9. import org.springframework.context.annotation.Configuration;
    10.  
    11. import javax.sql.DataSource;
    12. import java.util.HashMap;
    13. import java.util.Map;
    14.  
    15. /**
    16.  * @author WangDH
    17.  * @create 2022-11-10 11:42
    18.  *
    19.  *
    20.  * 自定义两个数据源，主库数据源，从库数据源
    21.  */
    22. @Configuration
    23. public class DataSourceConfig {
    24.  
    25.     //定义Mysql主库数据源
    26.     @Bean
    27.     @ConfigurationProperties("spring.datasource.master")//从配置文件读取spring.datasource.master开头的相关配置进行数据源初始化
    28.     public DataSource DataSourceMaster(){
    29.         return DataSourceBuilder.create().build();
    30.     }
    31.  
    32.     //定义Mysql从库数据源
    33.     @Bean
    34.     @ConfigurationProperties("spring.datasource.slave")
    35.     public DataSource DataSourceSlave(){
    36.         return DataSourceBuilder.create().build();
    37.     }
    38.  
    39.     @Bean
    40.     public DataSource myRoutingDataSource(
    41.             //@Qualifier 类似于@Autowired注解实现Spring依赖注入，但@Qualifier用来指定应该注入特定类型的bean，防止依赖注入冲突
    42.             @Qualifier("DataSourceMaster") DataSource dataSourceMaster,
    43.             @Qualifier("DataSourceSlave") DataSource dataSourceSlave)
    44.     {
    45.         Map targetDataSource=new HashMap<>(2);
    46.         targetDataSource.put(DBTypeEnum.MASTER,dataSourceMaster);
    47.         targetDataSource.put(DBTypeEnum.SLAVE,dataSourceSlave);
    48.  
    49.         MyRoutingDataSource routingDataSource=new MyRoutingDataSource();
    50.         routingDataSource.setDefaultTargetDataSource(dataSourceMaster);
    51.         routingDataSource.setTargetDataSources(targetDataSource);
    52.         return routingDataSource;
    53.     }
    54.  
    55. }

    创建MyBatisConfig.java,其中构建SqlSessionFactory 对象访问动态数据源，以便这获取到mybatis操作数据库的 SqlSession 对象，进而通过mybatis操作数据库。

    MyBatisConfig.java代码如下。（这里有个坑，报错是【FileNotFoundException: class path resource [mappers/*.xml] cannot be opened because it does not exist】，原因是，要写成getResources 不要误写成getResource，见注释）

    1. package com.wdh.springbootreadwritesplitmysql.config;
    2.  
    3. import org.apache.ibatis.session.SqlSessionFactory;
    4. import org.mybatis.spring.SqlSessionFactoryBean;
    5. import org.springframework.context.annotation.Bean;
    6. import org.springframework.context.annotation.Configuration;
    7. import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
    8. import org.springframework.jdbc.datasource.DataSourceTransactionManager;
    9. import org.springframework.transaction.PlatformTransactionManager;
    10. import org.springframework.transaction.annotation.EnableTransactionManagement;
    11.  
    12.  
    13.  
    14. import javax.annotation.Resource;
    15. import javax.sql.DataSource;
    16.  
    17. /**
    18.  * @author WangDH
    19.  * @create 2022-11-10 14:26
    20.  */
    21. @EnableTransactionManagement
    22. @Configuration
    23. public class MyBatisConfig {
    24.  
    25.     @Resource(name="myRoutingDataSource") //@Resource默认按byName自动注入
    26.     private DataSource myRoutingDataSource;
    27.  
    28.     @Bean
    29.     public SqlSessionFactory sqlSessionFactory() throws Exception{
    30.         ///org.springframework.core.io.Resource resourceMappersXml=new PathMatchingResourcePatternResolver().getResource("classpath:mappers/*.xml");
    31.         //上述代码报错：Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'class path resource [mappers/*.xml]'; nested exception is java.io.FileNotFoundException: class path resource [mappers/*.xml] cannot be opened because it does not exist
    32.  
    33.         org.springframework.core.io.Resource[] resourceMappersXml=new PathMatchingResourcePatternResolver().getResources("classpath:mappers/*.xml");
    34.         //注意这里是getResources 不要误写成getResource
    35.         //参考https://www.cnblogs.com/jev-0987/p/12839193.html
    36.         //getResource()：        //1.从类的根路径下获取文件
    37.         //getResources():        //1.获取所有类路径下的指定文件
    38.  
    39.  
    40.         SqlSessionFactoryBean sqlSessionFactoryBean=new SqlSessionFactoryBean();
    41.         sqlSessionFactoryBean.setDataSource(myRoutingDataSource);
    42.         sqlSessionFactoryBean.setMapperLocations(
    43.                 resourceMappersXml
    44.         );
    45.         SqlSessionFactory sqlSessionFactory= sqlSessionFactoryBean.getObject();
    46.         return sqlSessionFactory;
    47.     }
    48.  
    49.     @Bean
    50.     public PlatformTransactionManager platformTransactionManager(){
    51.         return new DataSourceTransactionManager(myRoutingDataSource);
    52.     }
    53.  
    54. }

    编码两个自定义注解，用于标记方法是操作主库还是从库。

    Master.java代码

    1. package com.wdh.springbootreadwritesplitmysql.annotation;
    2.  
    3. /**
    4.  * @author WangDH
    5.  * @create 2022-11-10 14:03
    6.  *
    7.  * 定义一种注解，加此注解的方法查询主库（主数据库）
    8.  */
    9. public @interface Master {
    10. }
    Slave.java代码
    1. package com.wdh.springbootreadwritesplitmysql.annotation;
    2.  
    3. /**
    4.  * @author WangDH
    5.  * @create 2022-11-11 11:25
    6.  * 定义一种注解，加此注解的方法查询从库（从数据库）
    7.  */
    8. public @interface Slave {
    9. }

    关键部分来了，切面编程，aop。

    DataSourceAop.java代码如下
    1. package com.wdh.springbootreadwritesplitmysql.aop;
    2.  
    3. import com.wdh.springbootreadwritesplitmysql.bean.DBContextHolder;
    4. import org.aspectj.lang.annotation.Aspect;
    5. import org.aspectj.lang.annotation.Before;
    6. import org.aspectj.lang.annotation.Pointcut;
    7. import org.springframework.stereotype.Component;
    8.  
    9. /**
    10.  * @author WangDH
    11.  * @create 2022-11-10 14:53
    12.  */
    13. @Aspect
    14. @Component
    15. public class DataSourceAop {
    16.  
    17. //    //读切面（条件：没有Master注解）
    18. //    @Pointcut(
    19. //            "!@annotation(com.wdh.springbootreadwritesplitmysql.annotation.Master)"  //如果使用!@annotation，则必须加&&(execution指定包范围，否则会导致所有方法都被切面捕获而导致启动失败
    20. //            +"&&(execution(* com.wdh.springbootreadwritesplitmysql.service.*.*(..)))"
    21. //    )
    22.     //切面切入点（条件：有Slave注解）的方法使用从库数据源
    23.     @Pointcut(
    24.             "@annotation(com.wdh.springbootreadwritesplitmysql.annotation.Slave)"
    25.     )
    26.     public void readPointcut(){}
    27.  
    28.  
    29.     //切面切入点，（条件：有Master注解）的方法使用主库数据源
    30.     @Pointcut(
    31.             "@annotation(com.wdh.springbootreadwritesplitmysql.annotation.Master)"
    32.                     //+"&&(execution(* com.wdh.springbootreadwritesplitmysql.service.*.*(..)))"
    33.     )
    34.     public void writePointcut(){}
    35.  
    36.     //Before方法，读切面前设置ThreadLocal里变量为slave
    37.     @Before("readPointcut()")
    38.     public void read(){
    39.         DBContextHolder.slave();
    40.     }
    41.  
    42.     //Before方法，写切面前设置ThreadLocal里变量为master
    43.     @Before("writePointcut()")
    44.     public void write(){
    45.         DBContextHolder.master();
    46.     }
    47.  
    48.  
    49. }

    入口主类代码

    SpringbootReadWriteSplitMysqlApplication.java

    注意，增加了@MapperScan扫描指定包，以便mybatis扫描到XXXMapper.java进行自动注入。

    1. package com.wdh.springbootreadwritesplitmysql;
    2.  
    3. import org.mybatis.spring.annotation.MapperScan;
    4. import org.springframework.boot.SpringApplication;
    5. import org.springframework.boot.autoconfigure.SpringBootApplication;
    6.  
    7. @SpringBootApplication
    8. @MapperScan("com.wdh.springbootreadwritesplitmysql.mapper")
    9. public class SpringbootReadWriteSplitMysqlApplication {
    10.  
    11.     public static void main(String[] args) {
    12.         SpringApplication.run(SpringbootReadWriteSplitMysqlApplication.class, args);
    13.  
    14.         //参考https://blog.csdn.net/qq_37171353/article/details/111999618
    15.         //参考https://github.com/cbeann/Demooo/tree/master/springboot-readwrite-separation-deno/src
    16.  
    17.         //前提：需要主从两个数据库
    18.         //启动springboot后浏览器访问【http://localhost:8080/product/hello】测试是否正常
    19.         //浏览器访问【http://localhost:8080/product/allm】读取主库
    20.         //浏览器访问【http://localhost:8080/product/alls】读取从库
    21.         //浏览器访问【http://localhost:8080/product/insert/M1336】写入主库。（如mysql做了主从复制，则自动复制到从库）
    22.  
    23.  
    24.     }
    25.  
    26. }

    创建WebAPI实现读主库、读从库、写主库

    Controller层 ProductController.java代码

    1. package com.wdh.springbootreadwritesplitmysql.controller;
    2.  
    3. import com.wdh.springbootreadwritesplitmysql.entity.Products;
    4. import com.wdh.springbootreadwritesplitmysql.service.ProductsService;
    5. import org.springframework.beans.factory.annotation.Autowired;
    6. import org.springframework.web.bind.annotation.GetMapping;
    7. import org.springframework.web.bind.annotation.PathVariable;
    8. import org.springframework.web.bind.annotation.RequestMapping;
    9. import org.springframework.web.bind.annotation.RestController;
    10.  
    11. import java.util.Date;
    12. import java.util.List;
    13.  
    14. /**
    15.  * @author WangDH
    16.  * @create 2022-11-10 16:54
    17.  */
    18. @RestController
    19. @RequestMapping("/product")
    20. public class ProductController {
    21.  
    22.     @Autowired
    23.     private ProductsService productsService;
    24.  
    25.     @GetMapping("/hello")
    26.     public String hello(){
    27.         return "ok,this is ProductController.";
    28.     }
    29.  
    30.     @GetMapping("/allm")
    31.     public List<Products> allM(){
    32.         List<Products> list=productsService.getAllMaster();
    33.         return list;
    34.     }
    35.  
    36.     @GetMapping("/alls")
    37.     public List<Products> allS(){
    38.         List<Products> list=productsService.getAllSlave();
    39.         return list;
    40.     }
    41.  
    42.     @GetMapping("/insert/{name}")
    43.     public String insert(@PathVariable("name") String prdName){
    44.  
    45.         Date date=new Date();
    46.         String prdNameJoin="SpringRW_"+prdName+"_"+date.toString();
    47.  
    48.         Products prd=new Products();
    49.  
    50.         prd.setPrdName(prdNameJoin);
    51.         prd.setPrdPrice((long)1110);
    52.         prd.setPrdDate(date);
    53.         prd.setCatId(2);
    54.  
    55.         int retIns=productsService.insert(prd);//进主库，可以测试关掉从库测试能否写成功。
    56.  
    57.         return "retIns="+retIns+","+(retIns>0?"ok":"fail");
    58.     }
    59.  
    60.  
    61.  
    62. }

    Service层代码，ProductsService.java

    特别注意，

    Service层写主库的方法上增加了@Master注解，例如insert方法;

    Service层读主库的方法上增加了@Master注解，例如getAllMaster();

    Service层读从库的方法上增加了@Slave注解，例如getAllSlave();

    通过添加不同注解的方式标记哪个方法操作主库，哪个方法操作从库。当然也有博友在aop中通过表达式方式匹配不同方法名，也可。DataSourceAop.java的注释中也有。

    1. package com.wdh.springbootreadwritesplitmysql.service;
    2.  
    3. import com.wdh.springbootreadwritesplitmysql.annotation.Master;
    4. import com.wdh.springbootreadwritesplitmysql.annotation.Slave;
    5. import com.wdh.springbootreadwritesplitmysql.entity.Products;
    6. import com.wdh.springbootreadwritesplitmysql.mapper.ProductsMapper;
    7. import org.springframework.beans.factory.annotation.Autowired;
    8. import org.springframework.stereotype.Service;
    9.  
    10. import java.util.List;
    11.  
    12. /**
    13.  * @author WangDH
    14.  * @create 2022-11-10 16:32
    15.  */
    16. @Service
    17. public class ProductsService {
    18.  
    19.     //注意，需要所有Service层访问数据库的方法必须增加@Slave或@Master注解，以标明是操作从库还是操作主库
    20.  
    21.  
    22.     @Autowired
    23.     private ProductsMapper productsMapper;
    24.  
    25.     @Slave
    26.     public List<Products> getAllSlave(){
    27.  
    28.         List<Products> listSlave= productsMapper.selectAll();
    29.         return listSlave;
    30.     }
    31.  
    32.     //标记为由主库读
    33.     @Master
    34.     public List<Products> getAllMaster(){
    35.  
    36.         List<Products> list= productsMapper.selectAll();
    37.         return list;
    38.     }
    39.  
    40.     //标记为进入主库写
    41.     @Master
    42.     public int insert(Products record){
    43.         return productsMapper.insert(record);
    44.     }
    45.  
    46. }

    Mapper层修改，ProductsMapper.java是自动生成的，由于没有查询全表的方法，这里手动增加一个方法

    List<Products> selectAll();

    ，同步需要修改ProductsMapper.xml。

    修改部分如下

    1.   <select id="selectAll" resultMap="BaseResultMap" >
    2.     select
    3.     <include refid="Base_Column_List" />
    4.     from products
    5.   select>

    ProductsMapper.java完整代码如下；

    1. package com.wdh.springbootreadwritesplitmysql.mapper;
    2.  
    3. import com.wdh.springbootreadwritesplitmysql.entity.Products;
    4.  
    5. import java.util.List;
    6.  
    7. public interface ProductsMapper {
    8.     /**
    9.      * This method was generated by MyBatis Generator.
    10.      * This method corresponds to the database table products
    11.      *
    12.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    13.      */
    14.     int deleteByPrimaryKey(Integer prdId);
    15.  
    16.     /**
    17.      * This method was generated by MyBatis Generator.
    18.      * This method corresponds to the database table products
    19.      *
    20.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    21.      */
    22.     int insert(Products record);
    23.  
    24.     /**
    25.      * This method was generated by MyBatis Generator.
    26.      * This method corresponds to the database table products
    27.      *
    28.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    29.      */
    30.     int insertSelective(Products record);
    31.  
    32.     /**
    33.      * This method was generated by MyBatis Generator.
    34.      * This method corresponds to the database table products
    35.      *
    36.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    37.      */
    38.     Products selectByPrimaryKey(Integer prdId);
    39.  
    40.     //wdh自定义增加的查询函数，需要ProductsMapper.xml有配置selectAll查询sql
    41.     List<Products> selectAll();
    42.     
    43.     /**
    44.      * This method was generated by MyBatis Generator.
    45.      * This method corresponds to the database table products
    46.      *
    47.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    48.      */
    49.     int updateByPrimaryKeySelective(Products record);
    50.  
    51.     /**
    52.      * This method was generated by MyBatis Generator.
    53.      * This method corresponds to the database table products
    54.      *
    55.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    56.      */
    57.     int updateByPrimaryKey(Products record);
    58. }

    ProductsMapper.xml全文

    1. "1.0" encoding="UTF-8" ?>
    2. mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
    3. <mapper namespace="com.wdh.springbootreadwritesplitmysql.mapper.ProductsMapper" >
    4.   <resultMap id="BaseResultMap" type="com.wdh.springbootreadwritesplitmysql.entity.Products" >
    5.     
    6.     <id column="prd_id" property="prdId" jdbcType="INTEGER" />
    7.     <result column="prd_name" property="prdName" jdbcType="VARCHAR" />
    8.     <result column="prd_price" property="prdPrice" jdbcType="DECIMAL" />
    9.     <result column="prd_date" property="prdDate" jdbcType="TIMESTAMP" />
    10.     <result column="cat_id" property="catId" jdbcType="INTEGER" />
    11.   resultMap>
    12.   <sql id="Base_Column_List" >
    13.     
    14.     prd_id, prd_name, prd_price, prd_date, cat_id
    15.   sql>
    16.   <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    17.     
    18.     select 
    19.     <include refid="Base_Column_List" />
    20.     from products
    21.     where prd_id = #{prdId,jdbcType=INTEGER}
    22.   select>
    23.   
    24.   <select id="selectAll" resultMap="BaseResultMap" >
    25.     select
    26.     <include refid="Base_Column_List" />
    27.     from products
    28.   select>
    29.   <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    30.     
    31.     delete from products
    32.     where prd_id = #{prdId,jdbcType=INTEGER}
    33.   delete>
    34.   <insert id="insert" parameterType="com.wdh.springbootreadwritesplitmysql.entity.Products" >
    35.     
    36.     insert into products (prd_id, prd_name, prd_price, 
    37.       prd_date, cat_id)
    38.     values (#{prdId,jdbcType=INTEGER}, #{prdName,jdbcType=VARCHAR}, #{prdPrice,jdbcType=DECIMAL}, 
    39.       #{prdDate,jdbcType=TIMESTAMP}, #{catId,jdbcType=INTEGER})
    40.   insert>
    41.   <insert id="insertSelective" parameterType="com.wdh.springbootreadwritesplitmysql.entity.Products" >
    42.     
    43.     insert into products
    44.     <trim prefix="(" suffix=")" suffixOverrides="," >
    45.       <if test="prdId != null" >
    46.         prd_id,
    47.       if>
    48.       <if test="prdName != null" >
    49.         prd_name,
    50.       if>
    51.       <if test="prdPrice != null" >
    52.         prd_price,
    53.       if>
    54.       <if test="prdDate != null" >
    55.         prd_date,
    56.       if>
    57.       <if test="catId != null" >
    58.         cat_id,
    59.       if>
    60.     trim>
    61.     <trim prefix="values (" suffix=")" suffixOverrides="," >
    62.       <if test="prdId != null" >
    63.         #{prdId,jdbcType=INTEGER},
    64.       if>
    65.       <if test="prdName != null" >
    66.         #{prdName,jdbcType=VARCHAR},
    67.       if>
    68.       <if test="prdPrice != null" >
    69.         #{prdPrice,jdbcType=DECIMAL},
    70.       if>
    71.       <if test="prdDate != null" >
    72.         #{prdDate,jdbcType=TIMESTAMP},
    73.       if>
    74.       <if test="catId != null" >
    75.         #{catId,jdbcType=INTEGER},
    76.       if>
    77.     trim>
    78.   insert>
    79.   <update id="updateByPrimaryKeySelective" parameterType="com.wdh.springbootreadwritesplitmysql.entity.Products" >
    80.     
    81.     update products
    82.     <set >
    83.       <if test="prdName != null" >
    84.         prd_name = #{prdName,jdbcType=VARCHAR},
    85.       if>
    86.       <if test="prdPrice != null" >
    87.         prd_price = #{prdPrice,jdbcType=DECIMAL},
    88.       if>
    89.       <if test="prdDate != null" >
    90.         prd_date = #{prdDate,jdbcType=TIMESTAMP},
    91.       if>
    92.       <if test="catId != null" >
    93.         cat_id = #{catId,jdbcType=INTEGER},
    94.       if>
    95.     set>
    96.     where prd_id = #{prdId,jdbcType=INTEGER}
    97.   update>
    98.   <update id="updateByPrimaryKey" parameterType="com.wdh.springbootreadwritesplitmysql.entity.Products" >
    99.     
    100.     update products
    101.     set prd_name = #{prdName,jdbcType=VARCHAR},
    102.       prd_price = #{prdPrice,jdbcType=DECIMAL},
    103.       prd_date = #{prdDate,jdbcType=TIMESTAMP},
    104.       cat_id = #{catId,jdbcType=INTEGER}
    105.     where prd_id = #{prdId,jdbcType=INTEGER}
    106.   update>
    107. mapper>

    entity层的Products.java代码是自动生成的，代码未变，也附上。

    1. package com.wdh.springbootreadwritesplitmysql.entity;
    2.  
    3. import lombok.Data;
    4.  
    5. import java.util.Date;
    6.  
    7. @Data
    8. public class Products {
    9.     /**
    10.      * This field was generated by MyBatis Generator.
    11.      * This field corresponds to the database column products.prd_id
    12.      *
    13.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    14.      */
    15.     private Integer prdId;
    16.  
    17.     /**
    18.      * This field was generated by MyBatis Generator.
    19.      * This field corresponds to the database column products.prd_name
    20.      *
    21.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    22.      */
    23.     private String prdName;
    24.  
    25.     /**
    26.      * This field was generated by MyBatis Generator.
    27.      * This field corresponds to the database column products.prd_price
    28.      *
    29.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    30.      */
    31.     private Long prdPrice;
    32.  
    33.     /**
    34.      * This field was generated by MyBatis Generator.
    35.      * This field corresponds to the database column products.prd_date
    36.      *
    37.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    38.      */
    39.     private Date prdDate;
    40.  
    41.     /**
    42.      * This field was generated by MyBatis Generator.
    43.      * This field corresponds to the database column products.cat_id
    44.      *
    45.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    46.      */
    47.     private Integer catId;
    48.  
    49.     /**
    50.      * This method was generated by MyBatis Generator.
    51.      * This method returns the value of the database column products.prd_id
    52.      *
    53.      * @return the value of products.prd_id
    54.      *
    55.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    56.      */
    57.     public Integer getPrdId() {
    58.         return prdId;
    59.     }
    60.  
    61.     /**
    62.      * This method was generated by MyBatis Generator.
    63.      * This method sets the value of the database column products.prd_id
    64.      *
    65.      * @param prdId the value for products.prd_id
    66.      *
    67.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    68.      */
    69.     public void setPrdId(Integer prdId) {
    70.         this.prdId = prdId;
    71.     }
    72.  
    73.     /**
    74.      * This method was generated by MyBatis Generator.
    75.      * This method returns the value of the database column products.prd_name
    76.      *
    77.      * @return the value of products.prd_name
    78.      *
    79.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    80.      */
    81.     public String getPrdName() {
    82.         return prdName;
    83.     }
    84.  
    85.     /**
    86.      * This method was generated by MyBatis Generator.
    87.      * This method sets the value of the database column products.prd_name
    88.      *
    89.      * @param prdName the value for products.prd_name
    90.      *
    91.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    92.      */
    93.     public void setPrdName(String prdName) {
    94.         this.prdName = prdName == null ? null : prdName.trim();
    95.     }
    96.  
    97.     /**
    98.      * This method was generated by MyBatis Generator.
    99.      * This method returns the value of the database column products.prd_price
    100.      *
    101.      * @return the value of products.prd_price
    102.      *
    103.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    104.      */
    105.     public Long getPrdPrice() {
    106.         return prdPrice;
    107.     }
    108.  
    109.     /**
    110.      * This method was generated by MyBatis Generator.
    111.      * This method sets the value of the database column products.prd_price
    112.      *
    113.      * @param prdPrice the value for products.prd_price
    114.      *
    115.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    116.      */
    117.     public void setPrdPrice(Long prdPrice) {
    118.         this.prdPrice = prdPrice;
    119.     }
    120.  
    121.     /**
    122.      * This method was generated by MyBatis Generator.
    123.      * This method returns the value of the database column products.prd_date
    124.      *
    125.      * @return the value of products.prd_date
    126.      *
    127.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    128.      */
    129.     public Date getPrdDate() {
    130.         return prdDate;
    131.     }
    132.  
    133.     /**
    134.      * This method was generated by MyBatis Generator.
    135.      * This method sets the value of the database column products.prd_date
    136.      *
    137.      * @param prdDate the value for products.prd_date
    138.      *
    139.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    140.      */
    141.     public void setPrdDate(Date prdDate) {
    142.         this.prdDate = prdDate;
    143.     }
    144.  
    145.     /**
    146.      * This method was generated by MyBatis Generator.
    147.      * This method returns the value of the database column products.cat_id
    148.      *
    149.      * @return the value of products.cat_id
    150.      *
    151.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    152.      */
    153.     public Integer getCatId() {
    154.         return catId;
    155.     }
    156.  
    157.     /**
    158.      * This method was generated by MyBatis Generator.
    159.      * This method sets the value of the database column products.cat_id
    160.      *
    161.      * @param catId the value for products.cat_id
    162.      *
    163.      * @mbggenerated Thu Nov 10 16:13:23 CST 2022
    164.      */
    165.     public void setCatId(Integer catId) {
    166.         this.catId = catId;
    167.     }
    168. }

    验证读写分离

    背景，主库和从库中Products表的数据行数是不一样的。主库此表内记录多，从库此表内记录少。

    如果执行方法可以根据@Master或@Slave实现读写分离，目的即为达成。

    验证前准备：主从两个数据库已启动且可访问。

    启动springboot，IDEA控制台打印的成功日志如下

    1. "C:\Program Files\Java\jdk1.8.0_111\bin\java.exe" -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:D:\JavaDevEnv\JetBrains\IntelliJ IDEA 2018.3.6\lib\idea_rt.jar=62267:D:\JavaDevEnv\JetBrains\IntelliJ IDEA 2018.3.6\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_111\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\rt.jar;D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql\target\classes;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-web\2.3.7.RELEASE\spring-boot-starter-web-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter\2.3.7.RELEASE\spring-boot-starter-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot\2.3.7.RELEASE\spring-boot-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-autoconfigure\2.3.7.RELEASE\spring-boot-autoconfigure-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-logging\2.3.7.RELEASE\spring-boot-starter-logging-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;D:\JavaDevEnv\maven_repository\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;D:\JavaDevEnv\maven_repository\org\apache\logging\log4j\log4j-to-slf4j\2.13.3\log4j-to-slf4j-2.13.3.jar;D:\JavaDevEnv\maven_repository\org\apache\logging\log4j\log4j-api\2.13.3\log4j-api-2.13.3.jar;D:\JavaDevEnv\maven_repository\org\slf4j\jul-to-slf4j\1.7.30\jul-to-slf4j-1.7.30.jar;D:\JavaDevEnv\maven_repository\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;D:\JavaDevEnv\maven_repository\org\yaml\snakeyaml\1.26\snakeyaml-1.26.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-json\2.3.7.RELEASE\spring-boot-starter-json-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-databind\2.11.3\jackson-databind-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-annotations\2.11.3\jackson-annotations-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-core\2.11.3\jackson-core-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.11.3\jackson-datatype-jdk8-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.11.3\jackson-datatype-jsr310-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.11.3\jackson-module-parameter-names-2.11.3.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-tomcat\2.3.7.RELEASE\spring-boot-starter-tomcat-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\apache\tomcat\embed\tomcat-embed-core\9.0.41\tomcat-embed-core-9.0.41.jar;D:\JavaDevEnv\maven_repository\org\glassfish\jakarta.el\3.0.3\jakarta.el-3.0.3.jar;D:\JavaDevEnv\maven_repository\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.41\tomcat-embed-websocket-9.0.41.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-web\5.2.12.RELEASE\spring-web-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-beans\5.2.12.RELEASE\spring-beans-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-webmvc\5.2.12.RELEASE\spring-webmvc-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-context\5.2.12.RELEASE\spring-context-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-expression\5.2.12.RELEASE\spring-expression-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\projectlombok\lombok\1.18.16\lombok-1.18.16.jar;D:\JavaDevEnv\maven_repository\org\apache\commons\commons-lang3\3.10\commons-lang3-3.10.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-aop\2.3.7.RELEASE\spring-boot-starter-aop-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-aop\5.2.12.RELEASE\spring-aop-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\aspectj\aspectjweaver\1.9.6\aspectjweaver-1.9.6.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-data-jdbc\2.3.7.RELEASE\spring-boot-starter-data-jdbc-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-jdbc\2.0.6.RELEASE\spring-data-jdbc-2.0.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-relational\2.0.6.RELEASE\spring-data-relational-2.0.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-commons\2.3.6.RELEASE\spring-data-commons-2.3.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-tx\5.2.12.RELEASE\spring-tx-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\slf4j\slf4j-api\1.7.30\slf4j-api-1.7.30.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-jdbc\2.3.7.RELEASE\spring-boot-starter-jdbc-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\com\zaxxer\HikariCP\3.4.5\HikariCP-3.4.5.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-jdbc\5.2.12.RELEASE\spring-jdbc-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\mybatis\spring\boot\mybatis-spring-boot-starter\2.1.4\mybatis-spring-boot-starter-2.1.4.jar;D:\JavaDevEnv\maven_repository\org\mybatis\spring\boot\mybatis-spring-boot-autoconfigure\2.1.4\mybatis-spring-boot-autoconfigure-2.1.4.jar;D:\JavaDevEnv\maven_repository\org\mybatis\mybatis\3.5.6\mybatis-3.5.6.jar;D:\JavaDevEnv\maven_repository\org\mybatis\mybatis-spring\2.0.6\mybatis-spring-2.0.6.jar;D:\JavaDevEnv\maven_repository\Mysql\mysql-connector-java\8.0.22\mysql-connector-java-8.0.22.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-core\5.2.12.RELEASE\spring-core-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-jcl\5.2.12.RELEASE\spring-jcl-5.2.12.RELEASE.jar" com.wdh.springbootreadwritesplitmysql.SpringbootReadWriteSplitMysqlApplication
    2.  
    3.   .   ____          _            __ _ _
    4.  /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
    5. ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
    6.  \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
    7.   '  |____| .__|_| |_|_| |_\__, | / / / /
    8.  =========|_|==============|___/=/_/_/_/
    9.  :: Spring Boot ::        (v2.3.7.RELEASE)
    10.  
    11. 2022-11-11 16:43:26.762  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : Starting SpringbootReadWriteSplitMysqlApplication on 14JPYI7CBESDNFK with PID 2452 (D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql\target\classes started by Administrator in D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql)
    12. 2022-11-11 16:43:26.762  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : No active profile set, falling back to default profiles: default
    13. 2022-11-11 16:43:28.525  INFO 2452 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
    14. 2022-11-11 16:43:28.541  INFO 2452 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
    15. 2022-11-11 16:43:28.541  INFO 2452 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.41]
    16. 2022-11-11 16:43:28.606  INFO 2452 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
    17. 2022-11-11 16:43:28.606  INFO 2452 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1781 ms
    18. 2022-11-11 16:43:30.028  INFO 2452 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
    19. 2022-11-11 16:43:30.511  INFO 2452 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
    20. 2022-11-11 16:43:30.511  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : Started SpringbootReadWriteSplitMysqlApplication in 4.093 seconds (JVM running for 4.693)

    浏览器访问【http://localhost:8080/product/hello】测试未访问数据库时，仅rest服务是否正常，以下是正常截图。

    浏览器访问【http://localhost:8080/product/allm】读取主库，成功图示如下

    读取主库，IDEA控制台日志如下。可以看到在访问数据库时DBContextHolder.java打印出”切换到master“的日志。

    1. "C:\Program Files\Java\jdk1.8.0_111\bin\java.exe" -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:D:\JavaDevEnv\JetBrains\IntelliJ IDEA 2018.3.6\lib\idea_rt.jar=62267:D:\JavaDevEnv\JetBrains\IntelliJ IDEA 2018.3.6\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_111\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\rt.jar;D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql\target\classes;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-web\2.3.7.RELEASE\spring-boot-starter-web-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter\2.3.7.RELEASE\spring-boot-starter-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot\2.3.7.RELEASE\spring-boot-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-autoconfigure\2.3.7.RELEASE\spring-boot-autoconfigure-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-logging\2.3.7.RELEASE\spring-boot-starter-logging-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;D:\JavaDevEnv\maven_repository\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;D:\JavaDevEnv\maven_repository\org\apache\logging\log4j\log4j-to-slf4j\2.13.3\log4j-to-slf4j-2.13.3.jar;D:\JavaDevEnv\maven_repository\org\apache\logging\log4j\log4j-api\2.13.3\log4j-api-2.13.3.jar;D:\JavaDevEnv\maven_repository\org\slf4j\jul-to-slf4j\1.7.30\jul-to-slf4j-1.7.30.jar;D:\JavaDevEnv\maven_repository\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;D:\JavaDevEnv\maven_repository\org\yaml\snakeyaml\1.26\snakeyaml-1.26.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-json\2.3.7.RELEASE\spring-boot-starter-json-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-databind\2.11.3\jackson-databind-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-annotations\2.11.3\jackson-annotations-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-core\2.11.3\jackson-core-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.11.3\jackson-datatype-jdk8-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.11.3\jackson-datatype-jsr310-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.11.3\jackson-module-parameter-names-2.11.3.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-tomcat\2.3.7.RELEASE\spring-boot-starter-tomcat-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\apache\tomcat\embed\tomcat-embed-core\9.0.41\tomcat-embed-core-9.0.41.jar;D:\JavaDevEnv\maven_repository\org\glassfish\jakarta.el\3.0.3\jakarta.el-3.0.3.jar;D:\JavaDevEnv\maven_repository\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.41\tomcat-embed-websocket-9.0.41.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-web\5.2.12.RELEASE\spring-web-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-beans\5.2.12.RELEASE\spring-beans-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-webmvc\5.2.12.RELEASE\spring-webmvc-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-context\5.2.12.RELEASE\spring-context-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-expression\5.2.12.RELEASE\spring-expression-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\projectlombok\lombok\1.18.16\lombok-1.18.16.jar;D:\JavaDevEnv\maven_repository\org\apache\commons\commons-lang3\3.10\commons-lang3-3.10.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-aop\2.3.7.RELEASE\spring-boot-starter-aop-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-aop\5.2.12.RELEASE\spring-aop-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\aspectj\aspectjweaver\1.9.6\aspectjweaver-1.9.6.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-data-jdbc\2.3.7.RELEASE\spring-boot-starter-data-jdbc-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-jdbc\2.0.6.RELEASE\spring-data-jdbc-2.0.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-relational\2.0.6.RELEASE\spring-data-relational-2.0.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-commons\2.3.6.RELEASE\spring-data-commons-2.3.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-tx\5.2.12.RELEASE\spring-tx-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\slf4j\slf4j-api\1.7.30\slf4j-api-1.7.30.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-jdbc\2.3.7.RELEASE\spring-boot-starter-jdbc-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\com\zaxxer\HikariCP\3.4.5\HikariCP-3.4.5.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-jdbc\5.2.12.RELEASE\spring-jdbc-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\mybatis\spring\boot\mybatis-spring-boot-starter\2.1.4\mybatis-spring-boot-starter-2.1.4.jar;D:\JavaDevEnv\maven_repository\org\mybatis\spring\boot\mybatis-spring-boot-autoconfigure\2.1.4\mybatis-spring-boot-autoconfigure-2.1.4.jar;D:\JavaDevEnv\maven_repository\org\mybatis\mybatis\3.5.6\mybatis-3.5.6.jar;D:\JavaDevEnv\maven_repository\org\mybatis\mybatis-spring\2.0.6\mybatis-spring-2.0.6.jar;D:\JavaDevEnv\maven_repository\Mysql\mysql-connector-java\8.0.22\mysql-connector-java-8.0.22.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-core\5.2.12.RELEASE\spring-core-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-jcl\5.2.12.RELEASE\spring-jcl-5.2.12.RELEASE.jar" com.wdh.springbootreadwritesplitmysql.SpringbootReadWriteSplitMysqlApplication
    2.  
    3.   .   ____          _            __ _ _
    4.  /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
    5. ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
    6.  \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
    7.   '  |____| .__|_| |_|_| |_\__, | / / / /
    8.  =========|_|==============|___/=/_/_/_/
    9.  :: Spring Boot ::        (v2.3.7.RELEASE)
    10.  
    11. 2022-11-11 16:43:26.762  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : Starting SpringbootReadWriteSplitMysqlApplication on 14JPYI7CBESDNFK with PID 2452 (D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql\target\classes started by Administrator in D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql)
    12. 2022-11-11 16:43:26.762  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : No active profile set, falling back to default profiles: default
    13. 2022-11-11 16:43:28.525  INFO 2452 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
    14. 2022-11-11 16:43:28.541  INFO 2452 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
    15. 2022-11-11 16:43:28.541  INFO 2452 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.41]
    16. 2022-11-11 16:43:28.606  INFO 2452 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
    17. 2022-11-11 16:43:28.606  INFO 2452 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1781 ms
    18. 2022-11-11 16:43:30.028  INFO 2452 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
    19. 2022-11-11 16:43:30.511  INFO 2452 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
    20. 2022-11-11 16:43:30.511  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : Started SpringbootReadWriteSplitMysqlApplication in 4.093 seconds (JVM running for 4.693)
    21. 2022-11-11 16:44:12.596  INFO 2452 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
    22. 2022-11-11 16:44:12.596  INFO 2452 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
    23. 2022-11-11 16:44:12.610  INFO 2452 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 14 ms
    24. 切换到master
    25. 2022-11-11 16:46:07.003  INFO 2452 --- [nio-8080-exec-4] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
    26. 2022-11-11 16:46:07.146  INFO 2452 --- [nio-8080-exec-4] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.

    浏览器访问【http://localhost:8080/product/alls】读取从库。成功图示如下。

     读取从库，IDEA控制台日志如下。可以看到在访问数据库时DBContextHolder.java打印出”切换到slave“的日志。

    1. "C:\Program Files\Java\jdk1.8.0_111\bin\java.exe" -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:D:\JavaDevEnv\JetBrains\IntelliJ IDEA 2018.3.6\lib\idea_rt.jar=62267:D:\JavaDevEnv\JetBrains\IntelliJ IDEA 2018.3.6\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_111\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\rt.jar;D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql\target\classes;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-web\2.3.7.RELEASE\spring-boot-starter-web-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter\2.3.7.RELEASE\spring-boot-starter-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot\2.3.7.RELEASE\spring-boot-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-autoconfigure\2.3.7.RELEASE\spring-boot-autoconfigure-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-logging\2.3.7.RELEASE\spring-boot-starter-logging-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;D:\JavaDevEnv\maven_repository\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;D:\JavaDevEnv\maven_repository\org\apache\logging\log4j\log4j-to-slf4j\2.13.3\log4j-to-slf4j-2.13.3.jar;D:\JavaDevEnv\maven_repository\org\apache\logging\log4j\log4j-api\2.13.3\log4j-api-2.13.3.jar;D:\JavaDevEnv\maven_repository\org\slf4j\jul-to-slf4j\1.7.30\jul-to-slf4j-1.7.30.jar;D:\JavaDevEnv\maven_repository\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;D:\JavaDevEnv\maven_repository\org\yaml\snakeyaml\1.26\snakeyaml-1.26.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-json\2.3.7.RELEASE\spring-boot-starter-json-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-databind\2.11.3\jackson-databind-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-annotations\2.11.3\jackson-annotations-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-core\2.11.3\jackson-core-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.11.3\jackson-datatype-jdk8-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.11.3\jackson-datatype-jsr310-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.11.3\jackson-module-parameter-names-2.11.3.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-tomcat\2.3.7.RELEASE\spring-boot-starter-tomcat-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\apache\tomcat\embed\tomcat-embed-core\9.0.41\tomcat-embed-core-9.0.41.jar;D:\JavaDevEnv\maven_repository\org\glassfish\jakarta.el\3.0.3\jakarta.el-3.0.3.jar;D:\JavaDevEnv\maven_repository\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.41\tomcat-embed-websocket-9.0.41.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-web\5.2.12.RELEASE\spring-web-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-beans\5.2.12.RELEASE\spring-beans-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-webmvc\5.2.12.RELEASE\spring-webmvc-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-context\5.2.12.RELEASE\spring-context-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-expression\5.2.12.RELEASE\spring-expression-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\projectlombok\lombok\1.18.16\lombok-1.18.16.jar;D:\JavaDevEnv\maven_repository\org\apache\commons\commons-lang3\3.10\commons-lang3-3.10.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-aop\2.3.7.RELEASE\spring-boot-starter-aop-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-aop\5.2.12.RELEASE\spring-aop-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\aspectj\aspectjweaver\1.9.6\aspectjweaver-1.9.6.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-data-jdbc\2.3.7.RELEASE\spring-boot-starter-data-jdbc-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-jdbc\2.0.6.RELEASE\spring-data-jdbc-2.0.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-relational\2.0.6.RELEASE\spring-data-relational-2.0.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-commons\2.3.6.RELEASE\spring-data-commons-2.3.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-tx\5.2.12.RELEASE\spring-tx-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\slf4j\slf4j-api\1.7.30\slf4j-api-1.7.30.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-jdbc\2.3.7.RELEASE\spring-boot-starter-jdbc-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\com\zaxxer\HikariCP\3.4.5\HikariCP-3.4.5.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-jdbc\5.2.12.RELEASE\spring-jdbc-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\mybatis\spring\boot\mybatis-spring-boot-starter\2.1.4\mybatis-spring-boot-starter-2.1.4.jar;D:\JavaDevEnv\maven_repository\org\mybatis\spring\boot\mybatis-spring-boot-autoconfigure\2.1.4\mybatis-spring-boot-autoconfigure-2.1.4.jar;D:\JavaDevEnv\maven_repository\org\mybatis\mybatis\3.5.6\mybatis-3.5.6.jar;D:\JavaDevEnv\maven_repository\org\mybatis\mybatis-spring\2.0.6\mybatis-spring-2.0.6.jar;D:\JavaDevEnv\maven_repository\Mysql\mysql-connector-java\8.0.22\mysql-connector-java-8.0.22.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-core\5.2.12.RELEASE\spring-core-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-jcl\5.2.12.RELEASE\spring-jcl-5.2.12.RELEASE.jar" com.wdh.springbootreadwritesplitmysql.SpringbootReadWriteSplitMysqlApplication
    2.  
    3.   .   ____          _            __ _ _
    4.  /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
    5. ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
    6.  \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
    7.   '  |____| .__|_| |_|_| |_\__, | / / / /
    8.  =========|_|==============|___/=/_/_/_/
    9.  :: Spring Boot ::        (v2.3.7.RELEASE)
    10.  
    11. 2022-11-11 16:43:26.762  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : Starting SpringbootReadWriteSplitMysqlApplication on 14JPYI7CBESDNFK with PID 2452 (D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql\target\classes started by Administrator in D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql)
    12. 2022-11-11 16:43:26.762  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : No active profile set, falling back to default profiles: default
    13. 2022-11-11 16:43:28.525  INFO 2452 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
    14. 2022-11-11 16:43:28.541  INFO 2452 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
    15. 2022-11-11 16:43:28.541  INFO 2452 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.41]
    16. 2022-11-11 16:43:28.606  INFO 2452 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
    17. 2022-11-11 16:43:28.606  INFO 2452 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1781 ms
    18. 2022-11-11 16:43:30.028  INFO 2452 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
    19. 2022-11-11 16:43:30.511  INFO 2452 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
    20. 2022-11-11 16:43:30.511  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : Started SpringbootReadWriteSplitMysqlApplication in 4.093 seconds (JVM running for 4.693)
    21. 2022-11-11 16:44:12.596  INFO 2452 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
    22. 2022-11-11 16:44:12.596  INFO 2452 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
    23. 2022-11-11 16:44:12.610  INFO 2452 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 14 ms
    24. 切换到master
    25. 2022-11-11 16:46:07.003  INFO 2452 --- [nio-8080-exec-4] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
    26. 2022-11-11 16:46:07.146  INFO 2452 --- [nio-8080-exec-4] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.
    27. 切换到slave
    28. 2022-11-11 16:49:04.559  INFO 2452 --- [nio-8080-exec-7] com.zaxxer.hikari.HikariDataSource       : HikariPool-2 - Starting...
    29. 2022-11-11 16:49:04.660  INFO 2452 --- [nio-8080-exec-7] com.zaxxer.hikari.HikariDataSource       : HikariPool-2 - Start completed.

    浏览器访问【http://localhost:8080/product/insert/M1651】写入主库。（因本示例mysql做了主从复制，所以主库的变更自动复制到从库了）

     日志如下，可以看到在调用写操作时自动切换到主库了。

    1. "C:\Program Files\Java\jdk1.8.0_111\bin\java.exe" -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:D:\JavaDevEnv\JetBrains\IntelliJ IDEA 2018.3.6\lib\idea_rt.jar=62267:D:\JavaDevEnv\JetBrains\IntelliJ IDEA 2018.3.6\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_111\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_111\jre\lib\rt.jar;D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql\target\classes;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-web\2.3.7.RELEASE\spring-boot-starter-web-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter\2.3.7.RELEASE\spring-boot-starter-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot\2.3.7.RELEASE\spring-boot-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-autoconfigure\2.3.7.RELEASE\spring-boot-autoconfigure-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-logging\2.3.7.RELEASE\spring-boot-starter-logging-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;D:\JavaDevEnv\maven_repository\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;D:\JavaDevEnv\maven_repository\org\apache\logging\log4j\log4j-to-slf4j\2.13.3\log4j-to-slf4j-2.13.3.jar;D:\JavaDevEnv\maven_repository\org\apache\logging\log4j\log4j-api\2.13.3\log4j-api-2.13.3.jar;D:\JavaDevEnv\maven_repository\org\slf4j\jul-to-slf4j\1.7.30\jul-to-slf4j-1.7.30.jar;D:\JavaDevEnv\maven_repository\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;D:\JavaDevEnv\maven_repository\org\yaml\snakeyaml\1.26\snakeyaml-1.26.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-json\2.3.7.RELEASE\spring-boot-starter-json-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-databind\2.11.3\jackson-databind-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-annotations\2.11.3\jackson-annotations-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\core\jackson-core\2.11.3\jackson-core-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.11.3\jackson-datatype-jdk8-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.11.3\jackson-datatype-jsr310-2.11.3.jar;D:\JavaDevEnv\maven_repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.11.3\jackson-module-parameter-names-2.11.3.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-tomcat\2.3.7.RELEASE\spring-boot-starter-tomcat-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\apache\tomcat\embed\tomcat-embed-core\9.0.41\tomcat-embed-core-9.0.41.jar;D:\JavaDevEnv\maven_repository\org\glassfish\jakarta.el\3.0.3\jakarta.el-3.0.3.jar;D:\JavaDevEnv\maven_repository\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.41\tomcat-embed-websocket-9.0.41.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-web\5.2.12.RELEASE\spring-web-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-beans\5.2.12.RELEASE\spring-beans-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-webmvc\5.2.12.RELEASE\spring-webmvc-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-context\5.2.12.RELEASE\spring-context-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-expression\5.2.12.RELEASE\spring-expression-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\projectlombok\lombok\1.18.16\lombok-1.18.16.jar;D:\JavaDevEnv\maven_repository\org\apache\commons\commons-lang3\3.10\commons-lang3-3.10.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-aop\2.3.7.RELEASE\spring-boot-starter-aop-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-aop\5.2.12.RELEASE\spring-aop-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\aspectj\aspectjweaver\1.9.6\aspectjweaver-1.9.6.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-data-jdbc\2.3.7.RELEASE\spring-boot-starter-data-jdbc-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-jdbc\2.0.6.RELEASE\spring-data-jdbc-2.0.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-relational\2.0.6.RELEASE\spring-data-relational-2.0.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\data\spring-data-commons\2.3.6.RELEASE\spring-data-commons-2.3.6.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-tx\5.2.12.RELEASE\spring-tx-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\slf4j\slf4j-api\1.7.30\slf4j-api-1.7.30.jar;D:\JavaDevEnv\maven_repository\org\springframework\boot\spring-boot-starter-jdbc\2.3.7.RELEASE\spring-boot-starter-jdbc-2.3.7.RELEASE.jar;D:\JavaDevEnv\maven_repository\com\zaxxer\HikariCP\3.4.5\HikariCP-3.4.5.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-jdbc\5.2.12.RELEASE\spring-jdbc-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\mybatis\spring\boot\mybatis-spring-boot-starter\2.1.4\mybatis-spring-boot-starter-2.1.4.jar;D:\JavaDevEnv\maven_repository\org\mybatis\spring\boot\mybatis-spring-boot-autoconfigure\2.1.4\mybatis-spring-boot-autoconfigure-2.1.4.jar;D:\JavaDevEnv\maven_repository\org\mybatis\mybatis\3.5.6\mybatis-3.5.6.jar;D:\JavaDevEnv\maven_repository\org\mybatis\mybatis-spring\2.0.6\mybatis-spring-2.0.6.jar;D:\JavaDevEnv\maven_repository\Mysql\mysql-connector-java\8.0.22\mysql-connector-java-8.0.22.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-core\5.2.12.RELEASE\spring-core-5.2.12.RELEASE.jar;D:\JavaDevEnv\maven_repository\org\springframework\spring-jcl\5.2.12.RELEASE\spring-jcl-5.2.12.RELEASE.jar" com.wdh.springbootreadwritesplitmysql.SpringbootReadWriteSplitMysqlApplication
    2.  
    3.   .   ____          _            __ _ _
    4.  /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
    5. ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
    6.  \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
    7.   '  |____| .__|_| |_|_| |_\__, | / / / /
    8.  =========|_|==============|___/=/_/_/_/
    9.  :: Spring Boot ::        (v2.3.7.RELEASE)
    10.  
    11. 2022-11-11 16:43:26.762  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : Starting SpringbootReadWriteSplitMysqlApplication on 14JPYI7CBESDNFK with PID 2452 (D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql\target\classes started by Administrator in D:\JavaWorkspace\IdeaProjects\SpringInAction\springboot-read-write-split-mysql)
    12. 2022-11-11 16:43:26.762  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : No active profile set, falling back to default profiles: default
    13. 2022-11-11 16:43:28.525  INFO 2452 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
    14. 2022-11-11 16:43:28.541  INFO 2452 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
    15. 2022-11-11 16:43:28.541  INFO 2452 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.41]
    16. 2022-11-11 16:43:28.606  INFO 2452 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
    17. 2022-11-11 16:43:28.606  INFO 2452 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1781 ms
    18. 2022-11-11 16:43:30.028  INFO 2452 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
    19. 2022-11-11 16:43:30.511  INFO 2452 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
    20. 2022-11-11 16:43:30.511  INFO 2452 --- [           main] SpringbootReadWriteSplitMysqlApplication : Started SpringbootReadWriteSplitMysqlApplication in 4.093 seconds (JVM running for 4.693)
    21. 2022-11-11 16:44:12.596  INFO 2452 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
    22. 2022-11-11 16:44:12.596  INFO 2452 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
    23. 2022-11-11 16:44:12.610  INFO 2452 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 14 ms
    24. 切换到master
    25. 2022-11-11 16:46:07.003  INFO 2452 --- [nio-8080-exec-4] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
    26. 2022-11-11 16:46:07.146  INFO 2452 --- [nio-8080-exec-4] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.
    27. 切换到slave
    28. 2022-11-11 16:49:04.559  INFO 2452 --- [nio-8080-exec-7] com.zaxxer.hikari.HikariDataSource       : HikariPool-2 - Starting...
    29. 2022-11-11 16:49:04.660  INFO 2452 --- [nio-8080-exec-7] com.zaxxer.hikari.HikariDataSource       : HikariPool-2 - Start completed.
    30. 切换到master

    再查询主库，ok，新增的数据已可查出。

    再查询从库（在Mysql实现了主从复制的场景下，主库新增的数据已经自动同步到从库了），ok

    拓展读写分离（写一个库，读多个库）

    思路：

    1.Mysql先实现一主多从，

    2.然后用Nginx为多个Mysql服务器建立反向代理在多个mysql上轮询实现负载均衡。例如Nginx将IP:3333端口暴露为多个Mysql负载均衡后对外的统一端口。

    3.将Nginx暴露出的对外数据访问端口IP:3333配置到springboot的application.propertities中读数据库的连接[spring.datasource.slave.jdbcUrl]中即可。

    4.上述仅改个springboot配置文件即可实现【mysql一主一从+springboot读写分离】或【mysql一主多从+springboot读写分离】，简单易用。

    mysql主从复制及Nginx读写分离可参考本人其他博文

    MySql 主从复制 双机热备 笔记_既择远方-风雨兼程的博客-CSDN博客

    Nginx 负载均衡 初步配置&验证 笔记_既择远方-风雨兼程的博客-CSDN博客

    Nginx Mysql负载均衡 初步配置及验证 笔记_既择远方-风雨兼程的博客-CSDN博客

    读写分离参考资料

    SpringBoot读写分离_CBeann的博客-CSDN博客_springboot 读写分离

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  • 原文地址：https://blog.csdn.net/wangdonghao137/article/details/127805751