尚硅谷-MyBatis的CRUD操作

项目结构：

User实体类代码：

package com.atguigu.mybatis.bean;

public class User {
	private int id;
	private String name;
	private int age;

	public User() {
		super();
	}

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

}

userMapper.xml映射文件代码：

<?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.atguigu.mybatis.bean.userMapper">
	<!--
		CRUD操作
	 -->
	<insert id="addUser" parameterType="User">
		insert into users(name,age) values(#{name},#{age})
	</insert>

	<delete id="deleteUser" parameterType="int">
		delete from users where id=#{id}
	</delete>

	<update id="updateUser" parameterType="User">
		update users set name=#{name},age=#{age} where id=#{id}
	</update>

	<select id="getUser" parameterType="int" resultType="User">
		select * from users where id=#{id}
	</select>

	<select id="getAllUsers" resultType="User">
		select * from users
	</select>
</mapper>

UserMapper注解类代码（要么用xml方式，要么用注解方式）：

package com.atguigu.mybatis.test2;

import java.util.List;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

import com.atguigu.mybatis.bean.User;

public interface UserMapper {

	@Insert("insert into users(name,age) values(#{name},#{age})")
	public int add(User user);

	@Delete("delete from users where id=#{id}")
	public int deleteById(int id);

	@Update("update users set name=#{name},age=#{age} where id=#{id}")
	public int update(User user);

	@Select("select * from users where id=#{id}")
	public User getById(int id);

	@Select("select * from users")
	public List<User> getAll();
}

获取SqlSessionFactory工厂的MybatisUtils代码：

package com.atguigu.mybatis.utils;

import java.io.InputStream;

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

public class MybatisUtils {

	public static SqlSessionFactory getFactory() {
		String resource = "conf.xml";
		InputStream inputStream = MybatisUtils.class.getClassLoader().getResourceAsStream(resource);

		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);

		return factory;
	}
}

配置文件conf.xml代码：

<?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>
	<properties resource="db.properties"/>
	<!-- 为实体类定义别名,简化sql映射xml文件中的引用-->
	<typeAliases>
		<!-- <typeAlias type="com.atguigu.mybatis.bean.User" alias="User"/> -->
		<!-- 该包下的所有类以其简单类名为实体类别名（如：User类的别名为User） -->
		<package name="com.atguigu.mybatis.bean"/>
	</typeAliases>
	<!--
		development : 开发模式
		work : 工作模式
 	-->
	<environments default="development">
		<environment id="development">
			<transactionManager type="JDBC"/>
			<dataSource type="POOLED">
				<property name="driver" value="${driver}" />
				<property name="url" value="${url}" />
				<property name="username" value="${name}" />
				<property name="password" value="${password}" />
			</dataSource>
		</environment>
	</environments>

	<mappers>
		<mapper resource="com/atguigu/mybatis/bean/userMapper.xml"/>
		<mapper class="com.atguigu.mybatis.test2.UserMapper"/>
	</mappers>
</configuration>

测试类Test2代码：

package com.atguigu.mybatis.test2;

import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.junit.Test;

import com.atguigu.mybatis.bean.User;
import com.atguigu.mybatis.utils.MybatisUtils;

/*
 * 测试: CRUD操作的XML的实现和注解实现
 */
public class Test2 {
	//--------------------------------测试XML的实现
	@Test
	public void testAdd(){
		SqlSessionFactory factory=MybatisUtils.getFactory();
		//默认是手动提交的
		SqlSession session=factory.openSession();

		String statement="com.atguigu.mybatis.bean.userMapper.addUser";
		int insert=session.insert(statement, new User(-1, "KK", 23));
		//提交事务
		session.commit();

		session.close();
		System.out.println(insert);
	}

	@Test
	public void testUpdate(){
		SqlSessionFactory factory=MybatisUtils.getFactory();
		//默认是手动提交
		SqlSession session=factory.openSession(true);
		String statement = "com.atguigu.mybatis.bean.userMapper.updateUser";
		int update =session.update(statement,new User(3, "KKK111", 25));
		session.close();
		System.out.println(update);
	}

	@Test
	public void testDelete(){
		SqlSessionFactory factory=MybatisUtils.getFactory();
		//默认是手动提交
		SqlSession session=factory.openSession(true);
		String statement = "com.atguigu.mybatis.bean.userMapper.deleteUser";
		int delete =session.delete(statement,3);
		session.close();
		System.out.println(delete);
	}

	@Test
	public void testGetUser(){
		SqlSessionFactory factory=MybatisUtils.getFactory();
		//默认是手动提交
		SqlSession session=factory.openSession(true);
		String statement = "com.atguigu.mybatis.bean.userMapper.getUser";
		User user=session.selectOne(statement, 1);
		session.close();
		System.out.println(user);
	}

	@Test
	public void testGetAll(){
		SqlSessionFactory factory=MybatisUtils.getFactory();
		//默认是手动提交
		SqlSession session=factory.openSession(true);
		String statement = "com.atguigu.mybatis.bean.userMapper.getAllUsers";
		List<User> list=session.selectList(statement);
		session.close();
		System.out.println(list);
	}

	//--------------------------------测试注解的实现
	@Test
	public void testAdd2(){
		SqlSessionFactory factory=MybatisUtils.getFactory();
		SqlSession session=factory.openSession(true);

		UserMapper mapper=session.getMapper(UserMapper.class);
		int add=mapper.add(new User(-1, "SS", 34));
		session.close();
		System.out.println(add);
	}
}

数据库配置代码db.properties：

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/mybatis
name=root
password=123456

可以在src下加入log4j的配置文件,打印日志信息：

-->首先添加   log4j-1.2.16.jar

-->然后：

log4j.properties（方式一）

        log4j.properties，
	log4j.rootLogger=DEBUG, Console
	#Console
	log4j.appender.Console=org.apache.log4j.ConsoleAppender
	log4j.appender.Console.layout=org.apache.log4j.PatternLayout
	log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n
	log4j.logger.java.sql.ResultSet=INFO
	log4j.logger.org.apache=INFO
	log4j.logger.java.sql.Connection=DEBUG
	log4j.logger.java.sql.Statement=DEBUG
	log4j.logger.java.sql.PreparedStatement=DEBUG

log4j.xml（方式二）

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
	<appender name="STDOUT" class="org.apache.log4j.ConsoleAppender">
		<layout class="org.apache.log4j.PatternLayout">
			<param name="ConversionPattern"
				value="%-5p %d{MM-dd HH:mm:ss,SSS} %m  (%F:%L) \n" />
		</layout>
	</appender>
	<logger name="java.sql">
		<level value="debug" />
	</logger>
	<logger name="org.apache.ibatis">
		<level value="debug" />
	</logger>
	<root>
		<level value="debug" />
		<appender-ref ref="STDOUT" />
	</root>
</log4j:configuration>