Mybatis学习之入门

1.概述

　　MyBatis原本是apache的一个开源项目iBatis, 2010年这个项目由apache software foundation迁移到了google code，并且改名为MyBatis，MyBatis 是一个基于Java的持久层框架。iBatis提供的持久层框架包括SQL Maps和Data Access Objects（DAO）， MyBatis 是支持普通 SQL查询，存储过程和高级映射的优秀持久层框架。MyBatis 消除了几乎所有的JDBC代码和参数的手工设置以及结果集的检索。MyBatis使用简单的XML或注解用于配置和原始映射，将接口和 Java 的POJOs（Plain Old Java Objects，普通的 Java对象）映射成数据库中的记录。

2.简单DEMO

　　(1)User.java

public class User {

    private long id;

    private String name;

    private String pwd;

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

}

(2)mybatis-configuration.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>
    <settings>
        <setting name="useGeneratedKeys" value="true" />
    </settings>
    <typeAliases>
        <typeAlias type="test.User" alias="user" />
    </typeAliases>
    <!--数据库参数配置 -->
    <environments default="development">
        <environment id="development">
            <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=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="test/sys_user.xml" />
    </mappers>
</configuration>

(3)sys_user.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="sysuer">
  <!-- 主键自增长 并且还回配置  useGeneratedKeys="true"  keyProperty="fid"-->
  <!-- user为bean简写 配置在 mybatis-configuration.xml的typeAliases中 -->
  <insert id="insert" parameterType="user" useGeneratedKeys="true"  keyProperty="id">
    insert into sys_user(name,pwd)values(#{name},#{pwd})
  </insert>
</mapper>

(4)Test.java

package test;

import java.io.Reader;

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 {
	public static void main(String[] args) {
		try {
			String resource="mybatis-configuration.xml";
			Reader reader=Resources.getResourceAsReader(resource);
			SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
			SqlSessionFactory factory = builder.build(reader);
			SqlSession session = factory.openSession();
			User user=new User();
			user.setName("zcs");
			user.setPwd("111");
			session.insert("sysuer.insert", user);
			session.commit();
			System.err.println(user.getId());
			
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}