Java框架 MyBatis的缓存 - 码农知识堂 - 文章详情页

Java框架 MyBatis的缓存
0、准备工作

1、引入依赖
```
<dependencies>
        
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatisartifactId>
            <version>3.5.7version>
        dependency>
 
        
        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
            <version>4.12version>
            <scope>testscope>
        dependency>
 
        
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <version>8.0.27version>
        dependency>
 
        
        <dependency>
            <groupId>log4jgroupId>
            <artifactId>log4jartifactId>
            <version>1.2.17version>
        dependency>
    dependencies>
```
2、数据表数据
```
CREATE TABLE t_dept(
    dept_id INT PRIMARY KEY AUTO_INCREMENT,
    dept_name VARCHAR(20)
);
 
CREATE TABLE t_emp(
    emp_id INT PRIMARY KEY AUTO_INCREMENT,
    emp_name VARCHAR(20),
    age INT,
    gender CHAR,
    dept_id INT
);
 
INSERT INTO t_dept(dept_name) VALUES ('A'),('B'),('C');
 
INSERT INTO t_emp(emp_name,age,gender,dept_id) VALUES
('张三',20,'女',1),
('李四',22,'女',2),
('王五',21,'男',3),
('赵六',23,'男',1),
('田七',21,'女',3);
```
3、创建与数据表相对应 java 实体类
```
public class Emp {
    private Integer empId;
    private String empName;
    private Integer age;
    private String gender;
    private Integer deptId;
 
    public Emp() {
    }
 
    public Emp(Integer empId, String empName, Integer age, String gender, Integer deptId) {
        this.empId = empId;
        this.empName = empName;
        this.age = age;
        this.gender = gender;
        this.deptId = deptId;
    }
 
    public Integer getEmpId() {
        return empId;
    }
 
    public void setEmpId(Integer empId) {
        this.empId = empId;
    }
 
    public String getEmpName() {
        return empName;
    }
 
    public void setEmpName(String empName) {
        this.empName = empName;
    }
 
    public Integer getAge() {
        return age;
    }
 
    public void setAge(Integer age) {
        this.age = age;
    }
 
    public String getGender() {
        return gender;
    }
 
    public void setGender(String gender) {
        this.gender = gender;
    }
 
    public Integer getDeptId() {
        return deptId;
    }
 
    public void setDeptId(Integer deptId) {
        this.deptId = deptId;
    }
 
    @Override
    public String toString() {
        return "Emp{" +
                "empId=" + empId +
                ", empName='" + empName + '\'' +
                ", age=" + age +
                ", gender='" + gender + '\'' +
                ", deptId=" + deptId +
                '}';
    }
}
```
```
public class Dept {
    private Integer deptId;
    private String deptName;
 
    public Dept(Integer deptId, String deptName) {
        this.deptId = deptId;
        this.deptName = deptName;
    }
 
    public Dept() {
    }
 
    public Integer getDeptId() {
        return deptId;
    }
 
    public void setDeptId(Integer deptId) {
        this.deptId = deptId;
    }
 
    public String getDeptName() {
        return deptName;
    }
 
    public void setDeptName(String deptName) {
        this.deptName = deptName;
    }
 
    @Override
    public String toString() {
        return "Dept{" +
                "deptId=" + deptId +
                ", deptName='" + deptName + '\'' +
                '}';
    }
}
```
4、jdbc.properties 文件
```
jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssm?serverTimezone=UTC
jdbc.username=root
jdbc.password=root
```
5、MyBaits 核心配置文件
```
configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    
 
    
    <properties resource="jdbc.properties"/>
 
    <typeAliases>
        <package name="com.chenyixin.ssm.pojo"/>
    typeAliases>
 
    
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
            dataSource>
        environment>
 
    environments>
 
    
    <mappers>
        
        <package name="com.chenyixin.ssm.mapper"/>
    mappers>
configuration>
```
6、工具类：
```
package com.chenyin.ssm.utils;
 
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 
import java.io.InputStream;
 
public class SqlSessionUtil {
 
    public static SqlSession getSqlSession() {
        try {
            // 获取核心的配置文件
            InputStream in = Resources.getResourceAsStream("mybatis-config.xml");
            // 创建 SqlSessionFactoryBuilder 对象
            SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
 
            // 通过核心配置文件多对应的字节输入流创建工厂类 SqlSessionFactory ,生产 SqlSession 对象
            SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(in);
 
            // 创建 SqlSession 对象(自动操作事务)
            return sqlSessionFactory.openSession(true);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
 
    }
}
```
7、log4j.xml配置文件
```
log4j:configuration SYSTEM "log4j.dtd">
 
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
 
    <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender">
        <param name="Encoding" value="UTF-8" />
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value="%-5p %d{MM-dd HH:mm:ss,SSS} %m  (%F:%L) \n" />
        layout>
    appender>
    <logger name="java.sql">
        <level value="debug" />
    logger>
    <logger name="org.apache.ibatis">
        <level value="info" />
    logger>
    <root>
        <level value="debug" />
        <appender-ref ref="STDOUT" />
    root>
log4j:configuration>
```
1、MyBatis 的一级缓存

MyBatis 的一级缓存是 SqlSession 级别的，即通过同一个 SqlSession 查询的数据会被缓存

再次使用同一个 SqlSession 查询同一条数据，会从缓存中获取

1.1、代码示例：

CacheMapper 接口：
```
public interface CacheMapper {
    /**
     * 跟据 empId 查询员工信息
     * @param empId
     * @return
     */
    Emp getEmpByEmpId(@Param("empId") Integer empId);
 
    /**
     * 添加单个员工信息
     * @param emp
     * @return
     */
    int insertEmp(Emp emp);
}
```
CacheMapper.xml 配置文件：
```
<mapper namespace="com.chenyixin.ssm.mapper.CacheMapper">
	
	<select id="getEmpByEmpId" resultType="emp">
		select *
		from t_emp
		where emp_id = #{empId}
	select>
 
	
	<insert id="insertEmp">
		insert into t_emp
		values (null, empName, age, gender, null);
	insert>
 
mapper>
```
测试：
```
    @Test
    public void getEmpByEmpId() {
        SqlSession sqlSession = SqlSessionUtil.getSqlSession();
        CacheMapper mapper1 = sqlSession.getMapper(CacheMapper.class);
        Emp emp1 = mapper1.getEmpByEmpId(1);
        Emp emp2 = mapper1.getEmpByEmpId(1);
        System.out.println(emp1);
        System.out.println(emp2);
    }
```
结果：

1.2、使一级缓存失效的四种情况

使一级缓存失效的四种情况：

        1) 不同的SqlSession对应不同的一级缓存

        2) 同一个SqlSession但是查询条件不同

        3) 同一个SqlSession两次查询期间执行了任何一次增删改操作

        4) 同一个SqlSession两次查询期间手动清空了缓存

① 不同的SqlSession对应不同的一级缓存
```
@Test
    public void test1() {
        SqlSession sqlSession1 = SqlSessionUtil.getSqlSession();
        CacheMapper mapper1 = sqlSession1.getMapper(CacheMapper.class);
 
        Emp emp1 = mapper1.getEmpByEmpId(1);
        Emp emp2 = mapper1.getEmpByEmpId(1);
        System.out.println(emp1);
        System.out.println(emp2);
 
        SqlSession sqlSession2 = SqlSessionUtil.getSqlSession();
        CacheMapper mapper2 = sqlSession2.getMapper(CacheMapper.class);
        
        Emp emp3 = mapper2.getEmpByEmpId(1);
        System.out.println(emp3);
    }
```
结果：

② 同一个SqlSession但是查询条件不同
```
   @Test
    public void test2() {
        SqlSession sqlSession = SqlSessionUtil.getSqlSession();
        CacheMapper mapper = sqlSession.getMapper(CacheMapper.class);
 
        Emp emp1 = mapper.getEmpByEmpId(1);
        System.out.println(emp1);
        
        Emp emp2 = mapper.getEmpByEmpId(2);
        System.out.println(emp2);
    }
```
结果：

③ 同一个SqlSession两次查询期间执行了任何一次增删改操作
```
@Test
    public void test3() {
        SqlSession sqlSession = SqlSessionUtil.getSqlSession();
        CacheMapper mapper = sqlSession.getMapper(CacheMapper.class);
 
        Emp emp1 = mapper.getEmpByEmpId(1);
        System.out.println(emp1);
 
        int i = mapper.insertEmp(new Emp(null, "小红", 23, "男"));
        System.out.println(i);
        
        Emp emp2 = mapper.getEmpByEmpId(1);
        System.out.println(emp2);
    }
```
结果：

④ 同一个SqlSession两次查询期间手动清空了缓存
```
    @Test
    public void test4() {
        SqlSession sqlSession = SqlSessionUtil.getSqlSession();
        CacheMapper mapper = sqlSession.getMapper(CacheMapper.class);
 
        Emp emp1 = mapper.getEmpByEmpId(1);
        System.out.println(emp1);
        
        sqlSession.clearCache();
 
        Emp emp2 = mapper.getEmpByEmpId(2);
        System.out.println(emp2);
    }
```
结果：

2、MyBatis 的二级缓存

MyBatis 的二级缓存是 SqlSessionFactory 级别的，即通过同一个 SqlSessionFactory 所获取的 SqlSession 对象

查询的数据会被缓存，在通过同一个 SqlSessionFactory 所获取的 SqlSession 查询相同的数据会从缓存中获取

MyBatis 的二级缓存开启的条件：

        a>在核心配置文件中，设置全局配置属性cacheEnabled="true"，默认为true，不需要设置

        b>在映射文件中设置标签

        c>二级缓存必须在SqlSession关闭或提交之后有效

        d>查询的数据所转换的实体类类型必须实现序列化的接口

代码示例：

1、在映射文件中设置标签

2、二级缓存必须在SqlSession关闭或提交之后有效
```
@Test
    public void test5() throws IOException {
        InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
        SqlSession sqlSession1 = sqlSessionFactory.openSession(true);
        CacheMapper mapper1 = sqlSession1.getMapper(CacheMapper.class);
        Emp emp1 = mapper1.getEmpByEmpId(1);
        System.out.println(emp1);
 
        // 需要关闭 SqlSession 对象 ，数据会从一级缓存被保存到二级缓存
        sqlSession1.close();
 
        SqlSession sqlSession2 = sqlSessionFactory.openSession(true);
        CacheMapper mapper2 = sqlSession2.getMapper(CacheMapper.class);
        Emp emp2 = mapper2.getEmpByEmpId(1);
        System.out.println(emp2);
        sqlSession2.close();
    }
```
3、查询的数据所转换的实体类类型必须实现序列化的接口

结果：

3、二级缓存的相关配置

在mapper配置文件中添加的cache标签可以设置一些属性：

①eviction属性：缓存回收策略，默认的是 LRU。

        LRU（Least Recently Used） – 最近最少使用的：移除最长时间不被使用的对象。

        FIFO（First in First out） – 先进先出：按对象进入缓存的顺序来移除它们。

        SOFT – 软引用：移除基于垃圾回收器状态和软引用规则的对象。

        WEAK – 弱引用：更积极地移除基于垃圾收集器状态和弱引用规则的对象。

②flushInterval属性：刷新间隔，单位毫秒

        默认情况是不设置，也就是没有刷新间隔，缓存仅仅调用语句时刷新

③size属性：引用数目，正整数

        代表缓存最多可以存储多少个对象，太大容易导致内存溢出

④readOnly属性：只读， true/false

        true：只读缓存；会给所有调用者返回缓存对象的相同实例。因此这些对象不能被修改。这提供了很重要的性能优势。

        false：读写缓存；会返回缓存对象的拷贝（通过序列化）。这会慢一些，但是安全，因此默认是 false。

4、MyBatis缓存查询的顺序

先查询二级缓存，因为二级缓存中可能会有其他程序已经查出来的数据，可以拿来直接使用。

如果二级缓存没有命中，再查询一级缓存

如果一级缓存也没有命中，则查询数据库

SqlSession关闭之后，一级缓存中的数据会写入二级缓存

5、整合第三方缓存EHCache

5.1、添加依赖
```
		
		<dependency>
			<groupId>org.mybatis.cachesgroupId>
			<artifactId>mybatis-ehcacheartifactId>
			<version>1.2.1version>
		dependency> 
		
		
		<dependency>
			<groupId>ch.qos.logbackgroupId>
			<artifactId>logback-classicartifactId>
			<version>1.2.3version>
		dependency>
```
5.2、各jar包功能

jar包名称

作用

mybatis-ehcache

Mybatis和EHCache的整合包

ehcache

EHCache核心包

slf4j-api

SLF4J日志门面包

logback-classic

支持SLF4J门面接口的一个具体实现

5.3、创建EHCache的配置文件ehcache.xml

注意：配置文件名 ehcache.xml 不可更改
```
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
		 xsi:noNamespaceSchemaLocation="../config/ehcache.xsd">
 
	
	<diskStore path="E:\java\temp"/>
	<defaultCache maxElementsInMemory="1000" 
				  maxElementsOnDisk="10000000" 
				  eternal="false" 
				  overflowToDisk="true"
				  timeToIdleSeconds="120" 
				  timeToLiveSeconds="120" 
				  diskExpiryThreadIntervalSeconds="120"
				  memoryStoreEvictionPolicy="LRU">
		
	defaultCache>
ehcache>
```
5.4、设置二级缓存的类型

mapper配置文件中添加的cache标签可以设置二级缓存的类型：
```
	<cache type="org.mybatis.caches.ehcache.EhcacheCache"/>
```
5.5、加入logback日志

存在SLF4J时，作为简易日志的log4j将失效，此时我们需要借助SLF4J的具体实现logback来打印日志。创建logback的配置文件logback.xml 注意：配置文件名 logback.xml 不可更改
```
<configuration debug="true">
	
	<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
		<encoder>
			
			
			<pattern>[%d{HH:mm:ss.SSS}] [%-5level] [%thread] [%logger]
				[%msg]%n
			pattern>
		encoder>
	appender>
	
	
	<root level="DEBUG">
		
		<appender-ref ref="STDOUT"/>
	root>
	
	<logger name="com.chenyixin.ssm.mapper" level="DEBUG"/>
configuration>
```
根据特殊需求指定局部日志级别 --》需要更改路径

5.6、EHCache配置文件说明
5.7、测试
```
    @Test
    public void test5() throws IOException {
        InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
        SqlSession sqlSession1 = sqlSessionFactory.openSession(true);
        CacheMapper mapper1 = sqlSession1.getMapper(CacheMapper.class);
        Emp emp1 = mapper1.getEmpByEmpId(1);
        System.out.println(emp1);
 
        // 需要关闭 SqlSession 对象 ，数据会从一级缓存被保存到二级缓存
        sqlSession1.close();
 
        SqlSession sqlSession2 = sqlSessionFactory.openSession(true);
        CacheMapper mapper2 = sqlSession2.getMapper(CacheMapper.class);
        Emp emp2 = mapper2.getEmpByEmpId(1);
        System.out.println(emp2);
        sqlSession2.close();
    }
```
5.8、结果

14:58:53,497 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback-test.xml]
14:58:53,498 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback.groovy]
14:58:53,498 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Found resource [logback.xml] at [file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/logback.xml]
14:58:53,560 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender]
14:58:53,562 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [STDOUT]
14:58:53,566 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property
14:58:53,585 |-INFO in ch.qos.logback.classic.joran.action.RootLoggerAction - Setting level of ROOT logger to DEBUG
14:58:53,585 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [STDOUT] to Logger[ROOT]
14:58:53,587 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.chenyixin.ssm.mapper] to DEBUG
14:58:53,587 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - End of configuration.
14:58:53,587 |-INFO in ch.qos.logback.classic.joran.JoranConfigurator@12c8a2c0 - Registering current configuration as safe fallback point
[14:58:53.590] [DEBUG] [main] [org.apache.ibatis.logging.LogFactory]
               [Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.]
[14:58:53.594] [DEBUG] [main] [org.apache.ibatis.io.VFS]
               [Class not found: org.jboss.vfs.VFS]
[14:58:53.594] [DEBUG] [main] [org.apache.ibatis.io.JBoss6VFS]
               [JBoss 6 VFS API is not available in this environment.]
[14:58:53.594] [DEBUG] [main] [org.apache.ibatis.io.VFS]
               [Class not found: org.jboss.vfs.VirtualFile]
[14:58:53.594] [DEBUG] [main] [org.apache.ibatis.io.VFS]
               [VFS implementation org.apache.ibatis.io.JBoss6VFS is not valid in this environment.]
[14:58:53.594] [DEBUG] [main] [org.apache.ibatis.io.VFS]
               [Using VFS adapter org.apache.ibatis.io.DefaultVFS]
[14:58:53.595] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Find JAR URL: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/pojo]
[14:58:53.595] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Not a JAR: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/pojo]
[14:58:53.619] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Reader entry: Dept.class]
[14:58:53.619] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Reader entry: Emp.class]
[14:58:53.619] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Listing file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/pojo]
[14:58:53.619] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Find JAR URL: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/pojo/Dept.class]
[14:58:53.619] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Not a JAR: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/pojo/Dept.class]
[14:58:53.625] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Reader entry: �� 4 =]
[14:58:53.625] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Find JAR URL: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/pojo/Emp.class]
[14:58:53.625] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Not a JAR: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/pojo/Emp.class]
[14:58:53.625] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Reader entry: �� 4 K]
[14:58:53.625] [DEBUG] [main] [org.apache.ibatis.io.ResolverUtil]
               [Checking to see if class com.chenyixin.ssm.pojo.Dept matches criteria [is assignable to Object]]
[14:58:53.627] [DEBUG] [main] [org.apache.ibatis.io.ResolverUtil]
               [Checking to see if class com.chenyixin.ssm.pojo.Emp matches criteria [is assignable to Object]]
[14:58:53.640] [DEBUG] [main] [org.apache.ibatis.datasource.pooled.PooledDataSource]
               [PooledDataSource forcefully closed/removed all connections.]
[14:58:53.640] [DEBUG] [main] [org.apache.ibatis.datasource.pooled.PooledDataSource]
               [PooledDataSource forcefully closed/removed all connections.]
[14:58:53.640] [DEBUG] [main] [org.apache.ibatis.datasource.pooled.PooledDataSource]
               [PooledDataSource forcefully closed/removed all connections.]
[14:58:53.640] [DEBUG] [main] [org.apache.ibatis.datasource.pooled.PooledDataSource]
               [PooledDataSource forcefully closed/removed all connections.]
[14:58:53.641] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Find JAR URL: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/test-classes/com/chenyixin/ssm/mapper]
[14:58:53.641] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Not a JAR: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/test-classes/com/chenyixin/ssm/mapper]
[14:58:53.641] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Reader entry: CacheMapperTest.class]
[14:58:53.641] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Listing file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/test-classes/com/chenyixin/ssm/mapper]
[14:58:53.642] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Find JAR URL: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/test-classes/com/chenyixin/ssm/mapper/CacheMapperTest.class]
[14:58:53.642] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Not a JAR: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/test-classes/com/chenyixin/ssm/mapper/CacheMapperTest.class]
[14:58:53.642] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Reader entry: �� 4 {]
[14:58:53.642] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Find JAR URL: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/mapper]
[14:58:53.642] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Not a JAR: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/mapper]
[14:58:53.642] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Reader entry: CacheMapper.class]
[14:58:53.642] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Reader entry: CacheMapper.xml]
[14:58:53.642] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Listing file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/mapper]
[14:58:53.642] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Find JAR URL: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/mapper/CacheMapper.class]
[14:58:53.642] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Not a JAR: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/mapper/CacheMapper.class]
[14:58:53.644] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Reader entry: �� 4 ]
[14:58:53.644] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Find JAR URL: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/mapper/CacheMapper.xml]
[14:58:53.644] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Not a JAR: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/com/chenyixin/ssm/mapper/CacheMapper.xml]
[14:58:53.645] [DEBUG] [main] [org.apache.ibatis.io.DefaultVFS]
               [Reader entry: ]
[14:58:53.645] [DEBUG] [main] [org.apache.ibatis.io.ResolverUtil]
               [Checking to see if class com.chenyixin.ssm.mapper.CacheMapperTest matches criteria [is assignable to Object]]
[14:58:53.645] [DEBUG] [main] [org.apache.ibatis.io.ResolverUtil]
               [Checking to see if class com.chenyixin.ssm.mapper.CacheMapper matches criteria [is assignable to Object]]
[14:58:53.665] [DEBUG] [main] [net.sf.ehcache.config.ConfigurationFactory]
               [Configuring ehcache from ehcache.xml found in the classpath: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/ehcache.xml]
[14:58:53.666] [DEBUG] [main] [net.sf.ehcache.config.ConfigurationFactory]
               [Configuring ehcache from URL: file:/E:/java/java%e5%ad%a6%e4%b9%a0/SSM/pro05-MyBatis-cache/target/classes/ehcache.xml]
[14:58:53.667] [DEBUG] [main] [net.sf.ehcache.config.ConfigurationFactory]
               [Configuring ehcache from InputStream]
[14:58:53.674] [DEBUG] [main] [net.sf.ehcache.config.BeanHandler]
               [Ignoring ehcache attribute xmlns:xsi]
[14:58:53.674] [DEBUG] [main] [net.sf.ehcache.config.BeanHandler]
               [Ignoring ehcache attribute xsi:noNamespaceSchemaLocation]
[14:58:53.674] [DEBUG] [main] [net.sf.ehcache.config.DiskStoreConfiguration]
               [Disk Store Path: E:\java\temp]
[14:58:53.682] [DEBUG] [main] [net.sf.ehcache.CacheManager]
               [Creating new CacheManager with default config]
[14:58:53.683] [DEBUG] [main] [net.sf.ehcache.util.PropertyUtil]
               [propertiesString is null.]
[14:58:53.688] [DEBUG] [main] [net.sf.ehcache.config.ConfigurationHelper]
               [No CacheManagerEventListenerFactory class specified. Skipping...]
[14:58:53.843] [DEBUG] [main] [net.sf.ehcache.Cache]
               [No BootstrapCacheLoaderFactory class specified. Skipping...]
[14:58:53.843] [DEBUG] [main] [net.sf.ehcache.Cache]
               [CacheWriter factory not configured. Skipping...]
[14:58:53.843] [DEBUG] [main] [net.sf.ehcache.config.ConfigurationHelper]
               [No CacheExceptionHandlerFactory class specified. Skipping...]
[14:58:53.858] [DEBUG] [main] [net.sf.ehcache.DiskStorePathManager]
               [Using diskstore path E:\java\temp]
[14:58:53.858] [DEBUG] [main] [net.sf.ehcache.DiskStorePathManager]
               [Holding exclusive lock on E:\java\temp\.ehcache-diskstore.lock]
[14:58:53.858] [DEBUG] [main] [net.sf.ehcache.store.disk.DiskStorageFactory]
               [Failed to delete file com%002echenyixin%002essm%002emapper%002e%0043ache%004dapper.data]
[14:58:53.858] [DEBUG] [main] [net.sf.ehcache.store.disk.DiskStorageFactory]
               [Failed to delete file com%002echenyixin%002essm%002emapper%002e%0043ache%004dapper.index]
[14:58:53.861] [DEBUG] [main] [net.sf.ehcache.store.disk.DiskStorageFactory]
               [Matching data file missing (or empty) for index file. Deleting index file E:\java\temp\com%002echenyixin%002essm%002emapper%002e%0043ache%004dapper.index]
[14:58:53.863] [DEBUG] [main] [net.sf.ehcache.store.disk.DiskStorageFactory]
               [Failed to delete file com%002echenyixin%002essm%002emapper%002e%0043ache%004dapper.index]
[14:58:53.901] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Pass-Through Statistic: LOCAL_OFFHEAP_SIZE]
[14:58:53.902] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Pass-Through Statistic: LOCAL_OFFHEAP_SIZE_BYTES]
[14:58:53.902] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Pass-Through Statistic: WRITER_QUEUE_LENGTH]
[14:58:53.902] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Pass-Through Statistic: REMOTE_SIZE]
[14:58:53.902] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Pass-Through Statistic: LAST_REJOIN_TIMESTAMP]
[14:58:53.908] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Operation Statistic: OFFHEAP_GET]
[14:58:53.908] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Operation Statistic: OFFHEAP_PUT]
[14:58:53.909] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Operation Statistic: OFFHEAP_REMOVE]
[14:58:53.909] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Operation Statistic: XA_COMMIT]
[14:58:53.909] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Operation Statistic: XA_ROLLBACK]
[14:58:53.910] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Operation Statistic: XA_RECOVERY]
[14:58:53.910] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Operation Statistic: CLUSTER_EVENT]
[14:58:53.910] [DEBUG] [main] [net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl]
               [Mocking Operation Statistic: NONSTOP]
[14:58:53.915] [DEBUG] [main] [net.sf.ehcache.Cache]
               [Initialised cache: com.chenyixin.ssm.mapper.CacheMapper]
[14:58:53.916] [DEBUG] [main] [net.sf.ehcache.config.ConfigurationHelper]
               [CacheDecoratorFactory not configured for defaultCache. Skipping for 'com.chenyixin.ssm.mapper.CacheMapper'.]
[14:58:53.963] [DEBUG] [main] [com.chenyixin.ssm.mapper.CacheMapper]
               [Cache Hit Ratio [com.chenyixin.ssm.mapper.CacheMapper]: 0.0]
[14:58:53.966] [DEBUG] [main] [org.apache.ibatis.transaction.jdbc.JdbcTransaction]
               [Opening JDBC Connection]
[14:58:54.376] [DEBUG] [main] [org.apache.ibatis.datasource.pooled.PooledDataSource]
               [Created connection 826865256.]
[14:58:54.380] [DEBUG] [main] [com.chenyixin.ssm.mapper.CacheMapper.getEmpByEmpId]
               [==> Preparing: select * from t_emp where emp_id = ?]
[14:58:54.405] [DEBUG] [main] [com.chenyixin.ssm.mapper.CacheMapper.getEmpByEmpId]
               [==> Parameters: 1(Integer)]
[14:58:54.420] [DEBUG] [main] [com.chenyixin.ssm.mapper.CacheMapper.getEmpByEmpId]
               [<== Total: 1]
Emp{empId=1, empName='张三', age=20, gender='女', dept=null}
[14:58:54.422] [DEBUG] [main] [net.sf.ehcache.store.disk.Segment]
               [put added 0 on heap]
[14:58:54.423] [DEBUG] [main] [org.apache.ibatis.transaction.jdbc.JdbcTransaction]
               [Closing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@3148f668]]
[14:58:54.423] [DEBUG] [main] [org.apache.ibatis.datasource.pooled.PooledDataSource]
               [Returned connection 826865256 to pool.]
[14:58:54.423] [DEBUG] [main] [com.chenyixin.ssm.mapper.CacheMapper]
               [Cache Hit Ratio [com.chenyixin.ssm.mapper.CacheMapper]: 0.5]
Emp{empId=1, empName='张三', age=20, gender='女', dept=null}

进程已结束,退出代码0

结果可以看出：查询语句只执行力了一次
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原文地址：https://blog.csdn.net/weixin_65637841/article/details/126325009