Mybatis入门程序

2016-11-18_235500.png

SqlMapConfig.xml(全局配置文件):

<?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>
    <!-- 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="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:8010/test?characterEncoding=utf-8" />
                <property name="username" value="root" />
                <property name="password" value="wazl2012" />
            </dataSource>
        </environment>
    </environments>
    <!-- 加载映射文件 -->
    <mappers>
        <mapper resource="sqlmap/User.xml"/>
    </mappers>
</configuration>

User.xml(映射配置文件):

<?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="test">
    <!-- 
          需求:根据id获取用户信息
         id:表示表示映射文件中的sql,将sql语句封装到mappedStatement对象中,将id称为Statement的 id
         parameterType:指定出入参数类型
         resultType:指定输出参数类型
         #{}表示一个占位符
         #{id}接收输入参数,参数名为id,如果输入的是简单类型,#{}中的参数名可以任意
    -->
    <select id="findUserById" parameterType="int" resultType="cn.ztc.mybatis.po.User">
        select * from user where id = #{id}
    </select>
    
    <!-- 
        需求:自定义条件查询用户列表 ,可能返回多条数据
        resultType:指定的就是单条记录所使用的java对象类型
        ${}表示拼接sql串,将接收到的参数不加任何修饰拼接在sql串中
        使用${}可能会引起sqk注入
        ${value}接收输入参数,如果输入的是简单类型,#{}中的参数名只能是value
    -->
    <select id="findUserByName" parameterType="java.lang.String" resultType="cn.ztc.mybatis.po.User">
        select * from user where username like '%${value}%'
    </select>
    
    <!-- 
        添加用户
        parameterType:输入参数类型是pojo
        #{}中指定pojo的属性名
     -->
    <insert id="insertUser" parameterType="cn.ztc.mybatis.po.User">
        <!-- 
            将插入数据库的主键返回到对象中
            select LAST_INSERT_ID():得到insert记录的主键值,只适用于自增主键
            keyProperty:将查询到的主键值设置到parameterType指定对象的某个属性
            order:相对于insert语句来说,select LAST_INSERT_ID()的执行顺序
         -->
        <selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer">
            select LAST_INSERT_ID()
        </selectKey>
        insert into user (username,birthday,sex,address) values (#{username},#{birthday},#{sex},#{address})
        <!-- 
            使用mysql的uuid生成主键
            执行过程:
            首先用过uuid()得到主键,将主键设置到user对象的id属性中
            其次在执行insert,从user对象中取出id属性值
         -->
         <!-- <selectKey keyProperty="id" order="BEFORE" resultType="java.lang.String">
            select uuid()
        </selectKey>
        insert into user (id,username,birthday,sex,address) values (#{id},#{username},#{birthday},#{sex},#{address}) -->
    </insert>
    
    <!-- 删除用户 -->
    <delete id="deleteUser" parameterType="java.lang.Integer">
        delete from user where id=#{id}
    </delete>
    
    <!-- 
        更新用户 
        #{id}:对应pojo的属性值
    -->
    <update id="updateUser" parameterType="cn.ztc.mybatis.po.User">
        update user set username=#{username},birthday=#{birthday},sex=#{sex},address=#{address} where id = #{id}
    </update>
</mapper>

User.java

package cn.ztc.mybatis.po;

import java.util.Date;

public class User {
    
    private int id;
    private String username;
    private String sex;
    private Date birthday;
    private String 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 + "]";
    }
    
}

MybatisFirst.java

package cn.ztc.mybatis.first;

import java.io.IOException;
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;
import org.junit.Test;

import cn.ztc.mybatis.po.User;

public class MybatisFirst {

    @Test
    public void findUserByIdTest() throws IOException{
        String resource = "SqlMapConfig.xml";
        //得到配置文件流
        InputStream inputStream = Resources.getResourceAsStream(resource);
        //创建会化工厂
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        //通过sqlSession操作数据库
        //第一个参数:映射文件中的[namespace].[statement id]
        //第二个参数:映射文件中匹配的resultType类型的对象
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //selectOne:查一条记录
        User user = sqlSession.selectOne("test.findUserById", 1);
        
        System.out.println(user);
        
        sqlSession.close();
    }
    
    @Test
    public void findUserByNameTest() throws IOException {
        String resource = "SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession();
        List<User> list = sqlSession.selectList("test.findUserByName", "小明");
        System.out.println(list);
        sqlSession.close();
    }
    
    @Test
    public void insertUserTest() throws IOException {
        String resource = "SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession();
        User user = new User();
        user.setUsername("王小军");
        user.setBirthday(new Date());
        user.setSex("1");
        user.setAddress("上海");
        sqlSession.insert("test.insertUser", user);
        
        sqlSession.commit();
        System.out.println(user.getId());
        sqlSession.close();
    }
    
    @Test
    public void deleteUserTest() throws IOException {
        String resource = "SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession();
        
        sqlSession.delete("test.deleteUser", 27);
        
        sqlSession.commit();
        sqlSession.close();
    }
    
    @Test
    public void updateUserTest() throws IOException {
        String resource = "SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession();
        User user = new User();
        user.setId(24);
        user.setUsername("张四丰");
        user.setBirthday(new Date());
        user.setSex("1");
        user.setAddress("上海");
        sqlSession.update("test.updateUser", user);
        
        sqlSession.commit();
        sqlSession.close();
    }

}

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