SSM框架（Spring + SpringMVC + MyBatis）学习笔记（01），第四课：MyBatis

本节介绍MyBatis的使用方法（没有和spring相结合，仅仅是mybatis的使用方法）

1、引入jar包

mybatis包（mybatis-3.5.0.jar）
mysql驱动包（mysql-connector-java-5.1.48-bin）
这两个jar包没有可以去官网下载

2、src目录下新建SqlMapConfig.xml

SqlMapConfig.xml用于指定数据库连接参数和SQL定义文件

<?xml version="1.0" encoding="UTF-8" ?>  
<!DOCTYPE configuration PUBLIC "-//ibatis.apache.org//DTD Config 3.0//EN" "http://ibatis.apache.org/dtd/ibatis-3-config.dtd">
<configuration>
	<environments default="environment">
		<environment id="environment">
			<transactionManager type="JDBC" />
			<dataSource type="POOLED">
				<property name="driver" value="com.mysql.jdbc.Driver" />
				<property name="url" value="jdbc:mysql://localhost:3306/test?useUnicode=true&amp;characterEncoding=utf8"/>
				<property name="username" value="root" />
				<property name="password" value="asdf123456" />
			</dataSource>
		</environment>
	</environments>
	
	<!-- 加载SQL定义文件 -->
	<mappers>
		<mapper resource="cn/springmybatis/entity/EmpMapper.xml" />
	</mappers>

</configuration> 

3、实体类创建

Emp实体类创建，主要用于返回值类型

package cn.springmybatis.entity;

import java.io.Serializable;

public class Emp implements Serializable{
	
	public Emp() {
		
	}
	
	public Emp(String name, Double salary) {
		super();
		this.name = name;
		this.salary = salary;
	}
	public Emp(String name, Integer sex, Double salary) {
		super();
		this.name = name;
		this.sex = sex;
		this.salary = salary;
	}
	private Integer id;
	private String name;
	private Integer sex;
	private Double salary;
	
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Integer getSex() {
		return sex;
	}
	public void setSex(Integer sex) {
		this.sex = sex;
	}
	public Double getSalary() {
		return salary;
	}
	public void setSalary(Double salary) {
		this.salary = salary;
	}
	
}

4、创建sql.xml文件

创建EmpMapper.xml文件

<?xml version="1.0" encoding="UTF-8" ?>  
<!DOCTYPE mapper PUBLIC "-//ibatis.apache.org//DTD Mapper 3.0//EN"      
 "http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd">
<!--namespace的值全局唯一-->
<mapper namespace="empsql">
	<select id="findAll" resultType="cn.springmybatis.entity.Emp">
		select * from emp
	</select>
	
	<select id="findBySex" parameterType="int" resultType="cn.springmybatis.entity.Emp" >
		select * from emp where sex=#{sex}
	</select>

	<select id="findById" parameterType="int" resultType="cn.springmybatis.entity.Emp">
		select * from emp where id=#{a}
	</select>
	
	<insert id="insert" parameterType="cn.springmybatis.entity.Emp">
		insert into emp (name,sex,salary) values(#{name},#{sex},#{salary})
	</insert>
	
	<delete id="deleteById" parameterType="int">
		delete from emp where id=#{id}
	</delete>
	
	<update id="updateById" parameterType="cn.springmybatis.entity.Emp">
		update emp set salary=#{salary} where name=#{name}
	</update>
	
</mapper>

5、获取SqlSession

package cn.springmybatis.test;

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 {
	
	public static SqlSession getSqlSession() {
		SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
		//加载SqlMapConfig.xml文件
		String conf = "SqlMapConfig.xml";
		InputStream confStream = 
				MyBatisUtil.class.getClassLoader().getResourceAsStream(conf);
		
		//获取SqlSessionFactory
		SqlSessionFactory factory = builder.build(confStream);
		
		//获取SqlSession
		SqlSession session = factory.openSession();
		return session;
		
	}

}

6、编写测试类

package cn.springmybatis.test;

import java.util.List;

import org.apache.ibatis.session.SqlSession;

import cn.springmybatis.entity.Emp;

public class TestEmp {
	
	public static void main(String[] args) {
		SqlSession session = MyBatisUtil.getSqlSession();
//		List<Emp> listEmp =session.selectList("findAll");
//		for(Emp emp: listEmp) {
//			System.out.println("id:"+emp.getId()+", name:"+emp.getName()+", sex:"+emp.getSex()+", salary:"+emp.getSalary());
//		}
		
//		List<Emp> listEmp =session.selectList("findBySex",0);
//		for(Emp emp: listEmp) {
//			System.out.println("id:"+emp.getId()+", name:"+emp.getName()+", sex:"+emp.getSex()+", salary:"+emp.getSalary());
//		}
		
//		Emp emp = session.selectOne("findById", 3);
//		System.out.println("id:"+emp.getId()+", name:"+emp.getName()+", sex:"+emp.getSex()+", salary:"+emp.getSalary());
		
//		Emp emp = new Emp("校长",1,100000.0);
//		int count =session.insert("insert", emp);
//		System.out.println(count);
		
//		int count = session.delete("deleteById", 1);
//		System.out.println(count);
		Emp emp = new Emp("小红",8000.0);
		session.update("updateById", emp);
		
		
		session.commit();//提交事务,增删改操作必须做事务提交
		session.close();//释放session
	}

}