MyBatis入门基本的配置介绍

工具：Eclipse

首先下载Mabatis所需要的jar包,导包



然后配置mybatis核心文件取名mybatis.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>
<properties resource="jdbc_mysql.properties"/>

<!-- 和spring整合后 environments配置将废除-->
<environments default="development">
<environment id="development">
<!-- 使用jdbc事务管理-->
<transactionManager type="JDBC" />
<!-- 数据库连接池-->
<dataSource type="POOLED">
<property name="driver" value="${jdbc.driver}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
</dataSource>
</environment>
</environments>

<mappers>
<mapper resource="User.xml"/>
</mappers>

</configuration>

然后配置连接数据库的资源文件，取名 jdbc_mysql.properties，取名要有意义

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8
jdbc.username=root
jdbc.password=123

然后配置日志文件，也就是查询时输出SQL语句

# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

然后创建一个实体User

package cn.web.entity;

import java.util.Date;

public class User {
private int id;
private String username;// 用户姓名
private String sex;// 性别
private Date birthday;// 生日
private String address;// 地址

public User() {
super();
}
public User(int id, String username, String sex, Date birthday, String address) {
super();
this.id = id;
this.username = username;
this.sex = sex;
this.birthday = birthday;
this.address = address;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "User [id=" + id + ", username=" + username + ", sex=" + sex + ", birthday=" + birthday + ", address="
+ address + "]";
}

}

然后就是Mybatis关键的一步了配置实体映射的查询语句

<?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="cn.web">

<select id="findUserid" parameterType="int" resultType="cn.web.entity.User">
SELECT * FROM USER WHERE id = #{id}
</select>

<select id="findUname" parameterType="String" resultType="cn.web.entity.User">
SELECT * FROM USER WHERE username LIKE #{username}
<!-- SELECT * FROM USER WHERE username LIKE concat('%',#{username},'%') -->
<!-- SELECT * FROM USER WHERE username LIKE '%' #{username} '%' -->
</select>

<delete id="deleteByid" parameterType="int">
delete from User where id=#{id}
</delete>

<insert id="insert" parameterType="cn.web.entity.User">
<selectKey databaseId="id" order="AFTER">
SELECT LAST_INSERT_ID()
</selectKey>
INSERT INTO USER (id,username,sex,birthday,address) VALUES (#{id},#{username},#{sex},#{birthday},#{address})
</insert>

<update id="update" parameterType="cn.web.entity.User">
UPDATE USER SET username=#{username} WHERE id=#{id}
</update>

</mapper>

最后编写一个数据连接的MybatisUtil，用来连接数据库

package cn.web.entity;

import java.io.IOException;
import java.io.InputStream;

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

public  class MyBatisUtil {

private static SqlSessionFactory sqlSessionFactory;

public static SqlSession getSqlSession(){
try {
InputStream is = Resources.getResourceAsStream("mybatis.xml");
if(sqlSessionFactory == null){
sqlSessionFactory=new SqlSessionFactoryBuilder().build(is);
}
return sqlSessionFactory.openSession();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}

最后一步编写Test测试文件

package cn.web.entity;

import java.io.InputStream;
import java.util.Date;
import java.util.List;

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

public class Test {
@org.junit.Test
public void testName() throws Exception {
//mybatis配置文件
String resource ="mybatis.xml" ;
//得到流对象
InputStream inputStream = Resources.getResourceAsStream(resource) ;
//创建会话工厂
SqlSessionFactory ssf=new SqlSessionFactoryBuilder().build(inputStream);
//通过会话工厂得到会话
SqlSession sqs= ssf.openSession();
//通过会话创建数据库
User user=sqs.selectOne("cn.web.findUserid",40);
System.out.println(user);
//List<User> list= sqs.selectList("cn.web.findUname", "张"+"%");
//sqs.insert("cn.web.insert",new User(40,"Make","2",new Date(),"珠海"));
//sqs.update("cn.web.update", new User(40,"小杨",null,null,null));
//sqs.delete("cn.web.deleteByid",30);
//SELECT LAST_INSERT_ID()
sqs.commit();
//关闭会话
sqs.close();
}

}

测试成功通过