mybatis_helloword(1)

摘录自：http://blog.csdn.net/y172158950/article/details/16979391

新的项目中用到mybatis,虽然不用自己写ORM的代码，但是借这个机会，学习一下。

本章目标：如题，helloWorld。

方法：在CSDN上下载一个demo，简单修改，能跑起来就OK。

1. 环境

  a)用到的jar：mybatis-3.0.5.jar ，MySQL-connector-java-5.0.8-bin.jar （只有一个jar，是不是很简单）

  b)mysql

  c)demo下载路径：http://download.csdn.net/detail/lihonghua168/3579586#comment

2.demo代码目录：

  a)configuration.xml ：mysql连接配置；基本就2块，一个是数据库连接配置，二是映射实体，相关映射文件。

<?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>
    <typeAliases>
    <!-- 映射的实体 -->
        <typeAlias type="com.test.Goods"/>
    </typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver"
                    value="com.mysql.jdbc.Driver" />
                <property name="url"
                    value="jdbc:mysql://127.0.0.1:3306/test" />
                <property name="username" value="root" />
                <property name="password" value="root" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!-- 数据连接成功后执行的对应实体映射文件数据库语句 -->
        <mapper resource="com/test/Mapper.xml" />
    </mappers>
</configuration>

  b)Mapper.xml ：sql语句配置文件；sql语句放配置文件，作用不多说，复用。

<?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.test.Mapper">
    <select id="selectGood" parameterType="int" resultType="Goods">
        select * from test where id =#{id}
    </select>
    <insert id="insertGood" parameterType="com.test.Goods" useGeneratedKeys="true" keyProperty="id"><!-- 后面两个表示主键自动生成的 -->
        insert into test (cateId , name , password , price , description , orderNo , updateTime) values(#{cateId} , #{name} , #{password} , #{price} , #{description} , #{orderNo} , #{updateTime});
    </insert>
    <delete id="deleteGood" parameterType="int">
        delete from test where id=#{id}
    </delete>
    <update id="updateGood" parameterType="com.test.Goods">
        update test set name=#{name},password=#{password},description=#{description},updateTime=#{updateTime} where id=#{id}
    </update>
</mapper>

  c)Goods.java ：结果集与表映射类；和hibernate不同，没有哪里写表与实体的映射关系（存疑）。

package com.test;
import java.util.Date;

/**
 * 实体,作为映射时的数据,所以所有字段的名称都必须和数据库里面的一样,不管什么数据库
 *
 *对应数据库表：
 create table test.test (
            id bigint(10) primary key AUTO_INCREMENT,
            cateId varchar(100),
            name varchar(100),
            password varchar(100),
            price double,
            description varchar(100),
            orderNo int,
            updateTime datetime
  );
 */
public class Goods {
    private long id;
    private String cateId;
    private String name;
    private String password;
    private double price;
    private String description;
    private int orderNo;
    private Date updateTime;

    public String getCateId() {
        return cateId;
    }

    public long getId() {
        return id;
    }

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

    public void setCateId(String cateId) {
        this.cateId = cateId;
    }

    public String getName() {
        return name;
    }

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

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public int getOrderNo() {
        return orderNo;
    }

    public void setOrderNo(int orderNo) {
        this.orderNo = orderNo;
    }

    public Date getUpdateTime() {
        return updateTime;
    }

    public void setUpdateTime(Date updateTime) {
        this.updateTime = updateTime;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

d)Test1.java ：dao类，测试类

package com.test;

import java.io.IOException;
import java.io.Reader;
import java.util.Date;

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 Test1{
    public static void main(String args[]) throws IOException {
        String resource = "com/test/configuration.xml";//获得xml(Mybatis)数据库连接的连接
        Reader reader = Resources.getResourceAsReader(resource);//读取里面的文件
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder()
                .build(reader);//创建session工厂
        SqlSession session = sessionFactory.openSession();//打开session
        new Test1().insert(session);
    }
    /**
     * 修改
     * @param session
     */
    public void update(SqlSession session){
        int falg=0;
        Goods g=new Goods();
        g.setId(1);
        g.setCateId("2");
        g.setName("huage");
        g.setPassword("huage");
        g.setDescription("He is me");
        g.setUpdateTime(new Date());
        falg=session.update("com.test.Mapper.updateGood", g);
        session.commit();
        if(falg==1){
            System.out.println("Data update successfully!");
        }else{
            System.out.println("Data update fail..");
        }
        session.close();
    }

    /**
     * 删除
     * @param session
     */
    public void delete(SqlSession session){
        //session.delete("1");
        int falg=0;
        falg=session.delete("com.test.Mapper.deleteGood", 1);
        session.commit();
        if(falg==1){
            System.out.println("Data delete successfully!");
        }else{
            System.out.println("Data dalete fail..");
        }
        session.close();

    }

    /**
     * 插入数据
     * @param session
     */
    public void insert(SqlSession session){
        Goods g=new Goods();
        g.setCateId("2");
        g.setName("huage");
        g.setPassword("huage");
        g.setPrice(5);
        g.setDescription("He is me");
        g.setOrderNo(2);
        g.setUpdateTime(new Date());
        int flag=0;
        flag=session.insert("com.test.Mapper.insertGood",g);
        session.commit();//一定要提交才能插入数据
        if(flag==1){
            System.out.println("Data inserted successfully!");
        }else{
            System.out.println("Data inserted fails!");
        }
        session.close();
    }
    /**
     * 查询
     * @param session
     */
    public void select(SqlSession session){
        try {
            Goods goods = (Goods) session.selectOne("com.test.Mapper.selectGood", 1);//执行数据操作

            System.out.println("good name is : " + goods.getName());
            System.out.println("description :="+goods.getDescription());
            System.out.println("orderNo :="+goods.getOrderNo());
            System.out.println("price :="+goods.getPrice());
            System.out.println("updateTiem :="+goods.getUpdateTime());
            System.out.println("id :="+goods.getId());
            System.out.println("password :="+goods.getPassword());
            System.out.println("cateid :="+goods.getCateId());
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            session.close();
        }
    }
}

 e)Test1.java流程分析

    i. 通过Reader类读取configuration.xml类容，获取数据库连接配置及相关实体类、sql语句配置信息。

    ii. 依据Reader的信息创建SqlSessionFactory。（这2步在实际工程中调用一次即可）

    iii. 创建SqlSession,相当于JDBC的Connection

    iv. insert数据：封装了sql语句,封装了映射过程(update,remove,select过程类似)

         1）封装Goods实体。

         2）调用session.insert方法：2个参数，"com.test.Mapper.insertGood“,去Mapper.xml找下，insert语句已经写好了；g,实体

         3）commit，close连接。

  f)数据库结果