spring学习日记-day7-整合mybatis

一、学习目标

spring整合MyBatis的原理主要涉及到将MyBatis的Mapper映射文件交由Spring容器管理，并将其注入到MyBatis的SqlSessionFactory中，从而实现两者的整合。

二、整合mybatis

1.写一个mybatis测试案例

项目结构：

1.数据库

CREATE DATABASE `mybatis`;
USE `mybatis`;

create table Users(
    id int not null auto_increment primary key,
    name varchar(10) not null,
    age int not null
);

insert into Users(id,name,age) values(null,'张三',20),(null,'李四',18);

2.实体类


public class User {
    private int id;  //id
    private String name;   //姓名
    private int age;   //密码

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public User(int id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

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

    public User() {
    }
}

2.编写接口

public interface UserMapper {
    public List<User> selectUser();
}

3.mybatisConfig配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <typeAliases>
        <package name="com.lzh.pojo"/>
    </typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=utf8&amp;useSSL=false"/>
                <property name="username" value="root"/>
                <property name="password" value="admin123"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <package name="com.lzh.dao"/>
    </mappers>
</configuration>

4.UserrMapper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.lzh.dao.UserMapper">
    <select id="selectUser" resultType="User">
        select * from users
    </select>
</mapper>

5.pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.lzh</groupId>
    <artifactId>spring-07</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.2</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.47</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.1.10.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.1.10.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.9.4</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>2.0.2</version>
    </dependency>

    </dependencies>
    <build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>
    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

</project>

6.测试

@Test
    public void selectUser() throws IOException {
        String resource = "MybatisConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> userList = mapper.selectUser();
        for (User user: userList){
            System.out.println(user);
        }
        sqlSession.close();
    }

2.整合mybatis方式一

1.配置数据源

    <!--配置数据源->
    定义一个数据源bean，id为"dataSource"，用于管理数据库连接。
    class属性指定了数据源的实现类为org.springframework.jdbc.datasource.DriverManagerDataSource，
    -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <!--
            设置数据库连接的URL。
            - useSSL=true&amp;useSSL=false：这里似乎有一个错误，通常只需要一个useSSL参数，并且应该保持一致。
              对于本地开发，通常不需要SSL，所以应设置为false。
            - useUnicode=true：指定使用Unicode字符集。
            - characterEncoding=utf8：指定字符编码为UTF-8。注意，从MySQL 5.5.3版本开始，建议使用utf8mb4代替utf8，
              以支持更广泛的Unicode字符，包括emoji表情等。
        -->
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&amp;useUnicode=true&amp;characterEncoding=utf8"/>
        <property name="username" value="root"/>
        <property name="password" value="admin123"/>
    </bean>

2.配置SqlSessionFactory，关联MyBatis注册,sqlSessionTemplate，关联sqlSessionFactory

     <!-- 配置SqlSessionFactory -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 注入数据源，这里的ref指向之前定义的数据源bean -->
        <property name="dataSource" ref="dataSource"/>
        <!-- 关联Mybatis的全局配置文件，MybatisConfig.xml中包含了MyBatis的设置，如别名、类型处理器、插件等 -->
        <property name="configLocation" value="classpath:MybatisConfig.xml"/>
        <!-- 指定Mapper XML文件的位置，MyBatis会根据这些XML文件来创建Mapper接口的实现 -->
        <!-- 注意：这里只指定了一个Mapper XML文件，如果有多个，可以使用逗号分隔或者使用通配符 -->
        <property name="mapperLocations" value="classpath:com/lzh/dao/UserMapper.xml"/>
    </bean>
    <!-- 注册sqlSessionTemplate，关联sqlSessionFactory -->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!-- 通过构造器注入SqlSessionFactory，使得SqlSessionTemplate能够管理SqlSession -->
        <!-- index="0"指定了构造器参数的索引，这里假设SqlSessionTemplate的构造器第一个参数就是SqlSessionFactory -->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>

3.增加接口实现类

public class UserDaoImpl implements UserMapper {
    // 注入SqlSessionTemplate，Spring容器会负责注入
    private SqlSessionTemplate sqlSession;
    // 通过构造器注入SqlSessionTemplate（推荐的方式，因为它支持Spring的依赖注入最佳实践）
    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }
    public List<User> selectUser() {
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.selectUser();
    }
}

4.注册bean

    <bean id="userDao" class="com.lzh.dao.UserDaoImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean>

5.修改mybatis配置文件

     <!--mappers>
        <package name="com.lzh.dao"/>
    </mappers-->

6.测试

@Test
    public void test2(){
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        UserMapper mapper = (UserMapper) context.getBean("userDao");
        List<User> user = mapper.selectUser();
        System.out.println(user);
    }

2.整合mybatis方式二

1.修改接口实现类

public class UserDaoImpl extends SqlSessionDaoSupport implements UserMapper {
    public List<User> selectUser() {
        UserMapper mapper = getSqlSession().getMapper(UserMapper.class);
        return mapper.selectUser();
    }
}

2.修改bean配置

 <!-- 注册sqlSessionTemplate，关联sqlSessionFactory -->
    <!--bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        < 通过构造器注入SqlSessionFactory，使得SqlSessionTemplate能够管理SqlSession -->
        <!-- index="0"指定了构造器参数的索引，这里假设SqlSessionTemplate的构造器第一个参数就是SqlSessionFactory -->
        <!--constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean-->

    <!--bean id="userDao" class="com.lzh.dao.UserDaoImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean-->
    <bean id="userDao" class="com.lzh.dao.UserDaoImpl">
        <property name="sqlSessionFactory" ref="sqlSessionFactory" />
    </bean>