MyBatis开发方法-优快云博客

本文链接：https://blog.youkuaiyun.com/hahajji/article/details/58015670

本节讲两种Mybatis开发方法：
（1）基于传统的Dao的开发方法
（2）基于Mapper代理的开发方法

【基于传统的Dao的开发方法】

目录结构**

lib下目录
这里写图片描述

UserDao.java

package com.zxy.mybatis.dao;

import com.zxy.mybatis.po.User;

/**
 * dao接口
 * @author zxy
 *
 */
public interface UserDao {
    //根据id查询用户信息
    public User findUserById(int id)throws Exception;
    //添加用户
    public void addUser(User user)throws Exception;
    //删除用户
    public void deleteUser(int id)throws Exception;
}

UserDaoImpl.java

/**
 * UserDao接口的实现类
 */
package com.zxy.mybatis.dao;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

import com.zxy.mybatis.po.User;

public class UserDaoImpl implements UserDao {

    //通过构造方法注入SqlSessionFactory
    private SqlSessionFactory sqlSessionFactory;
    public UserDaoImpl(SqlSessionFactory sqlSessionFactory){
        this.sqlSessionFactory=sqlSessionFactory;
    }

    @Override
    public User findUserById(int id) throws Exception {
        //因为sqlSession线程不安全，所以需要定义在方法中
        SqlSession sqlSession=sqlSessionFactory.openSession();
        User user=sqlSession.selectOne("test.findUserById", id);
        //释放资源
        sqlSession.close();
        return user;
    }

    @Override
    public void addUser(User user) throws Exception {
        SqlSession sqlSession=sqlSessionFactory.openSession();
        sqlSession.insert("test.insertUser", user);
        sqlSession.commit();
        sqlSession.close();
    }

    @Override
    public void deleteUser(int id) throws Exception {
        SqlSession sqlSession=sqlSessionFactory.openSession();
        sqlSession.delete("test.deleteUser", id);
        sqlSession.commit();
        sqlSession.close(); 
    }

}

User.java

package com.zxy.mybatis.po;

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 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 + "]";
    }

}

UserDaoImplTest.java

package com.zxy.mybatis.dao;

import static org.junit.Assert.*;

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

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;

import com.zxy.mybatis.po.User;

public class UserDaoImplTest {
    private SqlSessionFactory sqlSessionFactory;
    @Before
    public void setUp() throws Exception {
        String resource="SqlMapConfig.xml";
        InputStream inputStream=Resources.getResourceAsStream(resource);
        sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);        
    }

    @Test
    public void testFindUserById() throws Exception {
        UserDao userDao=new UserDaoImpl(sqlSessionFactory);
        User user=userDao.findUserById(16);
        System.out.println(user);
    }

    @Test
    public void testAddUser() throws Exception {
        UserDao userDao=new UserDaoImpl(sqlSessionFactory);
        User user=new User();
        user.setSex("1");
        user.setBirthday(new Date());
        user.setAddress("shanxi");
        user.setUsername("wnaghua");
        userDao.addUser(user);
    }

    @Test
    public void testDeleteUser() throws Exception {
        UserDao userDao=new UserDaoImpl(sqlSessionFactory);
        userDao.deleteUser(29);
    }

}

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="test">

<!-- 根据id获取用户信息 -->
    <select id="findUserById" parameterType="int" resultType="com.zxy.mybatis.po.User">
        select * from user where id=#{id}
    </select>
<!-- 根据用户名模糊查询用户信息 -->
    <select id="findUserByName" parameterType="java.lang.String" resultType="com.zxy.mybatis.po.User">
        SELECT * FROM USER WHERE username LIKE '%${value}%'
    </select>   
<!-- 插入用户 -->
     <insert id="insertUser" parameterType="com.zxy.mybatis.po.User">
        <selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer">
            SELECT LAST_INSERT_ID()
        </selectKey>
        insert into user(username,sex,birthday,address) values(#{username},#{sex},#{birthday},#{address})
     </insert>
<!-- 删除用户 -->
    <delete id="deleteUser" parameterType="java.lang.Integer">
        delete from user where id=#{id}
    </delete>
<!-- 更新用户 -->
    <update id="updateUser" parameterType="com.zxy.mybatis.po.User">
        update user set username=#{username},sex=#{sex},birthday=#{birthday},address=#{address} where id=#{id}
    </update>
</mapper>

log4j.properties

# 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

SqlMapConfig.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>
    <!-- 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:3306/mybatis?characterEncoding=utf-8" />
                <property name="username" value="root" />
                <property name="password" value="123" />
            </dataSource>
        </environment>
    </environments>
    <!-- 加载配置文件 -->
    <mappers>
        <mapper resource="sqlmap/User.xml"/>
    </mappers>
</configuration>

基于Mapper代理的开发方法

四点需要遵守的规则：
(1) 配置文件UserMapper.xml的配置文件的namesapce属性要设置为Mapper接口UserMapper.java的地址所在
(2) mapper.java接口中的方法名和mapper.xml中statement的id一致
(3) mapper.java接口中的方法输入参数类型和mapper.xml中 statement的parameterType指定的类型一致。
(4) mapper.java接口中的方法返回值类型和mapper.xml中statement
的resultType指定的类型一致。
这里写图片描述

目录结构

这里写图片描述

UserMapper.java

package com.zxy.mybatis.mapper;

import com.zxy.mybatis.po.User;

/**
 * mapper接口
 * @author zxy
 *
 */
public interface UserMapper {
    //根据id查询用户信息
    public User findUserById(int id)throws Exception;
    //添加用户
    public void insertUser(User user)throws Exception;
    //删除用户
    public void deleteUser(int id)throws Exception;
}

User.java

package com.zxy.mybatis.po;

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 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 + "]";
    }

}

UserMapperTest.java（测试文件）

package com.zxy.mybatis.mapper;

import static org.junit.Assert.*;

import java.io.InputStream;
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;
import org.junit.Before;
import org.junit.Test;

import com.zxy.mybatis.po.User;

public class UserMapperTest {

    private SqlSessionFactory sqlSessionFactory;
    @Before
    public void setUp() throws Exception {
        String resource="SqlMapConfig.xml";
        InputStream inputStream=Resources.getResourceAsStream(resource);
        sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);        
    }

    @Test
    public void testFindUserById() throws Exception {
        SqlSession sqlSession=sqlSessionFactory.openSession();
        UserMapper usermapper=sqlSession.getMapper(UserMapper.class);
        User user=usermapper.findUserById(1);
        sqlSession.close();
        System.out.println(user);
    }

    @Test
    public void testInsertUser() throws Exception {
        SqlSession sqlSession=sqlSessionFactory.openSession();
        UserMapper usermapper=sqlSession.getMapper(UserMapper.class);
        User user=new User();
        user.setSex("1");
        user.setBirthday(new Date());
        user.setUsername("力量12");
        user.setAddress("山阴县ads");
        usermapper.insertUser(user);
        sqlSession.commit();
        sqlSession.close();
    }

    @Test
    public void testDeleteUser() throws Exception {
        SqlSession sqlSession=sqlSessionFactory.openSession();
        UserMapper usermapper=sqlSession.getMapper(UserMapper.class);
        usermapper.deleteUser(34);
        sqlSession.commit();
        sqlSession.close();
    }

}

UserMapper.xml（方法没有完全实现）

<?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.zxy.mybatis.mapper.UserMapper">

<!-- 根据id获取用户信息 -->
    <select id="findUserById" parameterType="int" resultType="com.zxy.mybatis.po.User">
        select * from user where id=#{id}
    </select>
<!-- 根据用户名模糊查询用户信息 -->
    <select id="findUserByName" parameterType="java.lang.String" resultType="com.zxy.mybatis.po.User">
        SELECT * FROM USER WHERE username LIKE '%${value}%'
    </select>   
<!-- 插入用户 -->
     <insert id="insertUser" parameterType="com.zxy.mybatis.po.User">
        <selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer">
            SELECT LAST_INSERT_ID()
        </selectKey>
        insert into user(username,sex,birthday,address) values(#{username},#{sex},#{birthday},#{address})
     </insert>
<!-- 删除用户 -->
    <delete id="deleteUser" parameterType="java.lang.Integer">
        delete from user where id=#{id}
    </delete>
<!-- 更新用户 -->
    <update id="updateUser" parameterType="com.zxy.mybatis.po.User">
        update user set username=#{username},sex=#{sex},birthday=#{birthday},address=#{address} where id=#{id}
    </update>
</mapper>

log4j.properties

# 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

SqlMapConfig.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>
    <!-- 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:3306/mybatis?characterEncoding=utf-8" />
                <property name="username" value="root" />
                <property name="password" value="123" />
            </dataSource>
        </environment>
    </environments>
    <!-- 加载配置文件 -->
    <mappers>
        <mapper resource="mapper/UserMapper.xml"/>
    </mappers>
</configuration>

Mybatis学习【1】