复习Mybatis（都是之前的内容，不再解释）

6个需要修改或创建的文件

UserMapper

package com.Li.mapper;import com.Li.pojo.User;import java.util.List;public interface UserMapper {public List selectUser();
}

UserMapper.xml

select * from mybatis.user

User

package com.Li.pojo;import lombok.Data;@Data
public class User {private int id;private String name;private String pwd;
}

mybatis-config.xml

MyTest

import com.Li.mapper.UserMapper;
import com.Li.pojo.User;
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 org.junit.Test;import java.io.IOException;
import java.io.InputStream;
import java.util.List;public class MyTest {@Testpublic void selectUser() throws IOException {String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);SqlSession sqlSession = sqlSessionFactory.openSession();UserMapper mapper = sqlSession.getMapper(UserMapper.class);List userList = mapper.selectUser();for (User user: userList){System.out.println(user);}sqlSession.close();}}

pom.xml

spring-studycom.Li1.0-SNAPSHOT4.0.0spring-10-mybatis88junitjunit4.12mysqlmysql-connector-java8.0.29org.mybatismybatis3.5.2org.springframeworkspring-webmvc5.3.23org.springframeworkspring-jdbc6.0.0org.aspectjaspectjweaver1.9.4org.mybatismybatis-spring2.0.7org.projectlomboklombok1.18.10src/main/java**/*.properties**/*.xmlfalsesrc/main/resources**/*.properties**/*.xmlfalse

测试：

整合Mybatis方式一：（详解在代码中）

 UserMapperImpl：（接口的实现类，用来实现 UserMapper的Mybatis）

package com.Li.mapper;import com.Li.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;import java.util.List;public class UserMapperImpl implements UserMapper{//作用是简化测试类//我们的所有操作，都使用sqlSession来执行，在原来，现在都使用SqlSessionTemplateprivate SqlSessionTemplate sqlSession;public void setSqlSession(SqlSessionTemplate sqlSession) {this.sqlSession = sqlSession;}@Overridepublic List selectUser() {UserMapper mapper = sqlSession.getMapper(UserMapper.class);return mapper.selectUser();}
}

mybatis-config.xml：（简化删减里面的内容，将里面的内容移至spring-dao.xml中）

spring-dao.xml（整合了mybatis-config.xml与spring-dao.xml，使两种xml可以互通）

Mytest:(以spring的方式来做)

import com.Li.mapper.UserMapper;
import com.Li.pojo.User;
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 org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;import java.io.IOException;
import java.io.InputStream;
import java.util.List;public class MyTest {@Testpublic void selectUser() throws IOException {ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");UserMapper userMapper = context.getBean("userMapper", UserMapper.class);for (User user : userMapper.selectUser()) {System.out.println(user);}}}

 测试：

 Error loading class [org.springframework.jdbc.datasource.DriverManagerDataSource] for bean with name

会出现这样的红字报错。

直接改jar包的版本。。。这tm花了我好长时间找这个错误。。。无语

org.springframeworkspring-jdbc5.2.0.RELEASE

成功！

小结：你需要去对应MyTest的代码，来理解你每一步操作都是在干什么。

方式二：（简化方式一）

UserMapperImpl2：（继承实现）

package com.Li.mapper;import com.Li.pojo.User;
import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;import java.util.List;
//继承SqlSessionDaoSupport，不需要创建sqlSession了，可以直接用
public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper{@Overridepublic List selectUser() {SqlSession sqlSession = getSqlSession();UserMapper mapper = sqlSession.getMapper(UserMapper.class);return mapper.selectUser();}
}

applicationContext.xml：（将spring-dao.xml与mybatis-config.xml整合为一个）

修改之后测试成功！

重点在方式一的理解与掌握！