Mybatis总结（1）

大致流程：

声明实体类

定义sql映射xml文件

创建工具类

创建测试类：实现GURD

具体实现：

实体类User.java

package com.lin.domain;

public class User {
private int id;
private String name;
private int age;
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;
}
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
}

}

数据库配置文件：conf.xml

<?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>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<!-- 配置数据库连接信息 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/mybatis" />
<property name="username" value="root" />
<property name="password" value="" />
</dataSource>
</environment>
</environments>
</configuration>

Mybatis的配置：userMapper.xml

<?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.lin.mapper.userMapper">
<select id="getUser" parameterType="int"
resultType="com.lin.domain.User">
select * from users where id=#{id}
</select>

<!-- 创建用户(Create) -->
<insert id="addUser" parameterType="com.lin.domain.User">
insert into users(name,age) values(#{name},#{age})
</insert>

<!-- 删除用户(Remove) -->
<delete id="deleteUser" parameterType="int">
delete from users where id=#{id}
</delete>

<!-- 修改用户(Update) -->
<update id="updateUser" parameterType="com.lin.domain.User">
update users set name=#{name},age=#{age} where id=#{id}
</update>

<!-- 查询全部用户-->
<select id="getAllUsers" resultType="com.lin.domain.User">
select * from users
</select>

</mapper>

在conf.xml文件中注册userMapper.xml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>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<!-- 配置数据库连接信息 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/mybatis" />
<property name="username" value="root" />
<property name="password" value="" />
</dataSource>
</environment>
</environments>

<mappers>
<mapper resource="com/lin/mapper/userMapper.xml"/>
</mappers>

</configuration>

创建工具类MybatisUtil

package com.lin.util;

import java.io.InputStream;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class MyBatisUtil {

/**
* 获取SqlSessionFactory
* @return SqlSessionFactory
*/
public static SqlSessionFactory getSqlSessionFactory() {
String resource = "conf.xml";
InputStream is = MyBatisUtil.class.getClassLoader().getResourceAsStream(resource);
SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);
return factory;
}

/**
* 获取SqlSession
* @return SqlSession
*/
public static SqlSession getSqlSession() {
return getSqlSessionFactory().openSession();
}

/**
* 获取SqlSession
* @param isAutoCommit
*         true 表示创建的SqlSession对象在执行完SQL之后会自动提交事务
*         false 表示创建的SqlSession对象在执行完SQL之后不会自动提交事务，这时就需要我们手动调用sqlSession.commit()提交事务
* @return SqlSession
*/
public static SqlSession getSqlSession(boolean isAutoCommit) {
return getSqlSessionFactory().openSession(isAutoCommit);
}
}

创建测试类

package com.lin.test;

import java.util.List;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import com.lin.domain.User;
import com.lin.util.MyBatisUtil;

public class Test1 {
@Test
public void testAdd(){
//SqlSession sqlSession = MyBatisUtil.getSqlSession(false);
SqlSession sqlSession = MyBatisUtil.getSqlSession(true);
/**
* 映射sql的标识字符串，
* com.lin.mapper.userMapper是userMapper.xml文件中mapper标签的namespace属性的值，
* addUser是insert标签的id属性值，通过insert标签的id属性值就可以找到要执行的SQL
*/
String statement = "com.lin.mapper.userMapper.addUser";//映射sql的标识字符串
User user = new User();
user.setName("用户孤傲苍狼");
user.setAge(20);
//执行插入操作
int retResult = sqlSession.insert(statement,user);
//手动提交事务
//sqlSession.commit();
//使用SqlSession执行完SQL之后需要关闭SqlSession
sqlSession.close();
System.out.println(retResult);
}

@Test
public void testUpdate(){
SqlSession sqlSession = MyBatisUtil.getSqlSession(true);
/**
* 映射sql的标识字符串，
* com.lin.mapper.userMapper是userMapper.xml文件中mapper标签的namespace属性的值，
* updateUser是update标签的id属性值，通过update标签的id属性值就可以找到要执行的SQL
*/
String statement = "com.lin.mapper.userMapper.updateUser";//映射sql的标识字符串
User user = new User();
user.setId(3);
user.setName("孤傲苍狼");
user.setAge(25);
//执行修改操作
int retResult = sqlSession.update(statement,user);
//使用SqlSession执行完SQL之后需要关闭SqlSession
sqlSession.close();
System.out.println(retResult);
}

@Test
public void testDelete(){
SqlSession sqlSession = MyBatisUtil.getSqlSession(true);
/**
* 映射sql的标识字符串，
* com.lin.mapper.userMapper是userMapper.xml文件中mapper标签的namespace属性的值，
* deleteUser是delete标签的id属性值，通过delete标签的id属性值就可以找到要执行的SQL
*/
String statement = "com.lin.mapper.userMapper.deleteUser";//映射sql的标识字符串
//执行删除操作
int retResult = sqlSession.delete(statement,5);
//使用SqlSession执行完SQL之后需要关闭SqlSession
sqlSession.close();
System.out.println(retResult);
}

@Test
public void testGetAll(){
SqlSession sqlSession = MyBatisUtil.getSqlSession();
/**
* 映射sql的标识字符串，
* com.lin.mapper.userMapper是userMapper.xml文件中mapper标签的namespace属性的值，
* getAllUsers是select标签的id属性值，通过select标签的id属性值就可以找到要执行的SQL
*/
String statement = "com.lin.mapper.userMapper.getAllUsers";//映射sql的标识字符串
//执行查询操作，将查询结果自动封装成List<User>返回
List<User> lstUsers = sqlSession.selectList(statement);
//使用SqlSession执行完SQL之后需要关闭SqlSession
sqlSession.close();
System.out.println(lstUsers);
}

所有的代码都贴出来了，现在就可以跑了。