Java--Spring和MyBatis集成

Spring集成Mybatis主要使用的spring的IOC技术

创建项目步骤：

1、新建普通的maven项目

2、加入maven的依赖

（1）spring依赖

（2）mybatis依赖

（3）mysql驱动

（4）spring的事务依赖

（5）mybatis和spring集成依赖


<dependencies>
 
        
        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
            <version>4.11version>
            <scope>testscope>
        dependency>
 
        
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-contextartifactId>
            <version>5.2.5.RELEASEversion>
        dependency>
        
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-txartifactId>
            <version>5.2.5.RELEASEversion>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-jdbcartifactId>
            <version>5.2.5.RELEASEversion>
        dependency>
 
        
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatisartifactId>
            <version>3.5.1version>
        dependency>
 
        
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatis-springartifactId>
            <version>2.0.1version>
        dependency>
 
        
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <version>5.1.9version>
        dependency>
 
        
        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>druidartifactId>
            <version>1.2.6version>
        dependency>
 
    dependencies>

3、创建实体类（使用mysql数据库建一张User用户表）

4、创建dao接口和mapper文件

UserDao.java


public interface UserDao {
    /**
     * 插入一条user记录
     * @param user
     * @return
     */
    int insertUser(User user);
 
    /**
     * 查询所有用户
     * @param user
     * @return
     */
    List selectUsers(User user);
}

UserDao.xml


"1.0" encoding="UTF-8" ?>
mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.mycompany.dao.UserDao">
 
    <insert id="insertUser">
        insert into user values(#{userId},#{userName},#{email},#{age})
    insert>
 
    <select id="selectUsers" resultType="User">
        select user_id,user_name,email,age
        from user
        order by user_id desc
  select>
mapper>

5、创建mybatis主配置文件 mybatis-config.xml

（1）主配置文件中不再需要数据源的配置了；数据源要交给 Spring 容器管理

（2） mapper 映射文件的注册，使用标签，即只需给出 mapper 映射文件所在的包即可


"1.0" encoding="UTF-8" ?>
configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
 
    
    <settings>
        
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    settings>
 
    
    <typeAliases>
        
 
        
        <package name="com.mycompany.domain" />
    typeAliases>
 
 
    
    
 
 
    
    <mappers>
        
 
        
        <package name="com.mycompany.dao" />
 
    mappers>
 
configuration>

6、创建service接口和实现类，属性是dao


public interface UserService {
    //插入一条user记录
    int insertUser(User user);
 
    //查询所有用户
    List selectUsers(User user);
}
 
 
public class UserServiceImpl implements UserService {
 
    private UserDao userDao;
 
    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
 
    @Override
    public int insertUser(User user) {
        int nums = userDao.insertUser(user);
        return nums;
    }
 
    @Override
    public List selectUsers(User user) {
        List userList = userDao.selectUsers(user);
        return userList;
    }
}

7、创建spring的配置文件：声明mybatis对象交给spring创建

（1）数据源DataSource

这里使用阿里的Druid数据库连接池

Druid官网：https://github.com/alibaba/druid

DruidDataSource配置：

https://github.com/alibaba/druid/wiki/DruidDataSource%E9%85%8D%E7%BD%AE

其中Druid通用配置示例：


 <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close"> 
     <property name="url" value="${jdbc_url}" />
     <property name="username" value="${jdbc_user}" />
     <property name="password" value="${jdbc_password}" />
 
     <property name="filters" value="stat" />
 
     <property name="maxActive" value="20" />
     <property name="initialSize" value="1" />
     <property name="maxWait" value="6000" />
     <property name="minIdle" value="1" />
 
     <property name="timeBetweenEvictionRunsMillis" value="60000" />
     <property name="minEvictableIdleTimeMillis" value="300000" />
 
     <property name="testWhileIdle" value="true" />
     <property name="testOnBorrow" value="false" />
     <property name="testOnReturn" value="false" />
 
     <property name="poolPreparedStatements" value="true" />
     <property name="maxOpenPreparedStatements" value="20" />
 
     <property name="asyncInit" value="true" />
 bean>

在上面的配置中，通常你需要配置url、username、password，maxActive这三项。

Druid会自动跟url识别驱动类名，如果连接的数据库非常见数据库，配置属性driverClassName


    <context:property-placeholder location="classpath:jdbc.properties" />
 
    
    <bean id="myDataSource" class="com.alibaba.druid.pool.DruidDataSource"
            init-method="init" destroy-method="close">
        
        
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.user}" />
        <property name="password" value="${jdbc.password}" />
        <property name="maxActive" value="${jdbc.maxActive}" />
    bean>

（2）SqlSessionFactory


    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean" >
        
        <property name="dataSource" ref="myDataSource" />
 
        
        <property name="configLocation" value="classpath:mybatis-config.xml" />
    bean>

（3）Dao对象

Mapper 扫描配置器 MapperScannerConfigurer 会自动生成指定的基本包中 mapper 的代理对象。该 Bean 无需设置 id 属性。basePackage 使用分号或逗号设置多个包


    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
 
        
        <property name="basePackage" value="com.mycompany.dao" />
    bean>

（4）声明自定义的service


    <bean id="userService" class="com.mycompany.service.impl.UserServiceImpl">
        
        <property name="userDao" ref="userDao" />
    bean>

jdbc.properties；数据库属性配置文件


jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssm
jdbc.user=root
jdbc.password=123456
jdbc.maxActive=20

applicationContext.xml


"1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       https://www.springframework.org/schema/context/spring-context.xsd">
 
    
    <context:property-placeholder location="classpath:jdbc.properties" />
 
    
    <bean id="myDataSource" class="com.alibaba.druid.pool.DruidDataSource"
            init-method="init" destroy-method="close">
        
        
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.user}" />
        <property name="password" value="${jdbc.password}" />
        <property name="maxActive" value="${jdbc.maxActive}" />
    bean>
 
    
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean" >
        
        <property name="dataSource" ref="myDataSource" />
 
        
        <property name="configLocation" value="classpath:mybatis-config.xml" />
    bean>
 
    
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
 
        
        <property name="basePackage" value="com.mycompany.dao" />
    bean>
 
    
    <bean id="userService" class="com.mycompany.service.impl.UserServiceImpl">
        
        <property name="userDao" ref="userDao" />
    bean>
 
beans>

8、创建测试类


public class TestSpringMybatis {
    @Test
    public void testSpringMybatis(){
        String config = "applicationContext.xml";
        ApplicationContext ac = new ClassPathXmlApplicationContext(config);
 
        //获取容器中所有对象名
        String names[] = ac.getBeanDefinitionNames();
        for (String name:names){
            System.out.println("容器中对象名称：" + name + "    " + ac.getBean(name));
        }
    }
 
    @Test
    public void testDaoInsertUser(){
        String config = "applicationContext.xml";
        ApplicationContext ac = new ClassPathXmlApplicationContext(config);
 
        //获取容器中的Dao对象
        UserDao userDao = (UserDao) ac.getBean("userDao");
 
        User user = new User();
        user.setUserName("admin11");
        user.setEmail("admin@123.com");
        user.setAge(16);
 
        //spring和mybatis整合在一起使用，事务是自动提交的。 无需执行SqlSession.commit();
        int nums = userDao.insertUser(user);
        System.out.println("nums=" + nums);
    }
 
 
    @Test
    public void testServiceInsertUser(){
        String config = "applicationContext.xml";
        ApplicationContext ac = new ClassPathXmlApplicationContext(config);
 
        //获取容器中的Dao对象
        UserService userService = (UserService) ac.getBean("userService");
 
        User user = new User();
        user.setUserName("admin22");
        user.setEmail("admin21332@123.com");
        user.setAge(28);
        int nums = userService.insertUser(user);
        System.out.println("nums=" + nums);
    }
 
    @Test
    public void testSelect(){
        String config = "applicationContext.xml";
        ApplicationContext ac = new ClassPathXmlApplicationContext(config);
 
        //获取容器中的Dao对象
        UserService userService = (UserService) ac.getBean("userService");
 
        List userList = userService.selectUsers(null);
        for (User user:userList){
            System.out.println("user:" + user);
        }
    }
}

容器中输出对象

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原文地址：https://blog.csdn.net/MinggeQingchun/article/details/123114846