Spring学习笔记-05 整合Mybatis

前面我们曾经说到，Spring不仅仅是一个框架，还是一个集成环境的架子。在Mybatis中，最核心的类就是SqlSessionFactory，而将Mybatis整合到Spring中，实际上就是让Spring替代我们管理SqlSessionFactory。整合之后，所有的Mapper对象都会变为Bean保存在Spring容器中。

整合步骤：

1. 导入依赖、配置资源过滤

    <dependencies>
        <!--引入web会将所有的spring相关依赖全部导入-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.2.6.RELEASE</version>
        </dependency>
        <!--引入织入相关的依赖-->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.4</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <!--引入Spring测试环境-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.2.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>compile</scope>
        </dependency>
        <!--Mybatis 相关-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>
        <!--数据库连接驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.14</version>
        </dependency>
        <!--Mybatis、Spring整合包-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.2</version>
        </dependency>
        <!--Spring默认的非连接池方式-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.2.6.RELEASE</version>
        </dependency>
    </dependencies>

    <!--配置资源过滤-->
    <build>
        <resources>
            <resource>
                <!--资源目录-->
                <directory>src/main/java</directory>
                <!--要求包含的文件类型-->
                <includes>
                    <include>*.xml</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>

2.编写实体类

package com.zt.Eneity;

public class User {
    private Integer id;
    private String username;
    private String password;

    public User() {
    }

    public User(Integer id, String username, String password) {
        this.id = id;
        this.username = username;
        this.password = password;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

[注]：实体类与数据库内的记录相对应，因此每条记录对应的实体类对象都不一样，我们不应该把他们交给Spring容器管理。

3.描述Dao接口

package com.zt.Dao;

import com.zt.Eneity.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

import java.util.List;

@Mapper
public interface UserDao {

    Integer deleteUser(@Param("id") Integer id);
    Integer updateUser(User user);
    Integer addUser(User user);
    User findUserById(@Param("id") Integer id);
    List<User> getAllUsers();

}

4. 编写Mapper文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.zt.Dao.UserDao">
    <insert id="addUser" parameterType="com.zt.Eneity.User">
        insert into user(id,username,password) values (#{id},{username},#{password})
    </insert>
</mapper>

5. 在Spring配置文件中进行整合

<?xml version="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"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="
       http://www.springframework.org/schema/aop
       http://www.springframework.org/schema/aop/spring-aop.xsd
       http://www.springframework.org/schema/context
       https://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/beans
       https://www.springframework.org/schema/beans/spring-beans.xsd">

    <!--加载数据库连接信息文件-->
    <context:property-placeholder location="jdbc.properties"/>

    <!--Mapper扫描器-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!--配置要扫描的包-->
        <property name="basePackage" value="com.zt.Dao"/>
    </bean>

    <!--配置数据源-->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${jdbc.driver}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--配置SqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--指定使用的连接池-->
        <property name="dataSource" ref="dataSource"/>
        <!--关联Mybatis-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:com/zt/Dao/*.xml"/>
    </bean>

    <!--注册sqlSessionTemplate,关联SqlSessionFactory-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!--利用构造器注入-->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>

</beans>

6. 创建数据库表

use study_mybatis;
create table u_user(
    id int(8) primary key auto_increment,
    username varchar(20),
    password varchar(20)
)charset = utf8;

7. 测试

import com.zt.Dao.UserDao;
import com.zt.Eneity.User;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.List;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:spring-config.xml")
public class TestSpring {

    @Autowired
    private UserDao userDao;

    @Test
    public void springMybatisAddUser(){
        System.out.println(userDao.addUser(new User(null,"zzt","zjm")));
    }

    @Test
    public void springMybatisDeleteUserById(){
        System.out.println(userDao.deleteUserById(2));
    }

    @Test
    public void springMybatisGetAllUsers(){
        List<User> allUsers = userDao.getAllUsers();
        for (User allUser : allUsers) {
            System.out.println(allUser);
        }
    }

    @Test
    public void springMybatisQueryUserById(){
        System.out.println(userDao.queryUserById(1));
    }

    @Test
    public void springMybatisUpdateUserById(){
        System.out.println(userDao.updateUserById(new User(1, "zjm", "zzt")));
    }

}