MyBatis基础-07-mybatis一对多关联查询

pom.xml

 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.monkey1024</groupId>
  <artifactId>01mybatis</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>
  <dependencies>
	  	<dependency>
		    <groupId>org.mybatis</groupId>
		    <artifactId>mybatis</artifactId>
		    <version>3.4.6</version>
		</dependency>
		<dependency>
		    <groupId>mysql</groupId>
		    <artifactId>mysql-connector-java</artifactId>
		    <version>5.1.46</version>
		</dependency>
		<dependency>
		    <groupId>log4j</groupId>
		    <artifactId>log4j</artifactId>
		    <version>1.2.17</version>
		</dependency>
		<dependency>
		  <groupId>commons-io</groupId>
		  <artifactId>commons-io</artifactId>
		  <version>2.6</version>
		</dependency>
		<dependency>
		  <groupId>commons-fileupload</groupId>
		  <artifactId>commons-fileupload</artifactId>
		  <version>1.3.3</version>
		</dependency>
		<dependency>
		   <groupId>org.hibernate</groupId>
		   <artifactId>hibernate-validator</artifactId>
		   <version>6.0.9.Final</version>
		</dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.0.4.RELEASE</version>
        </dependency>

    </dependencies>
    <build>
    	<!-- 与工程名一致 -->
        <finalName>01mybatis</finalName>
        <resources>
        	<resource>
        		<directory>src/main/java</directory>
        		<includes>
        			<include>**/*.xml</include>
        		</includes>
        	</resource>
        </resources>
        <plugins>
            <!-- 编译插件，指定编译用的的jdk版本 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <!-- jdk的版本号 -->
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

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>

	<!-- 注册db配置文件 -->
	<properties resource="db.properties"/>
	
	<!-- mybatis配置文件中的标签是有顺序的 -->
	<!-- 注册实体类的权限定义名的别名 -->
	<typeAliases>
		<!-- 方式一:这种方式配置不太方便 -->
		<typeAlias type="com.monkey1024.bean.Student" alias="student"/>
		<!-- 方式二:mybatis会在这个包下搜索需要的javabean -->
		<package name="com.monkey1024.bean"/>
	</typeAliases>
	
	
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.user}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!--注册映射文件-->
        <mapper resource="com/monkey1024/dao/TeamMapper.xml"/>
    </mappers>
</configuration>

TeamMapper.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="com.monkey1024.dao.TeamDao">

	<resultMap id="teamMap" type="team">
		<!-- 篮球队的属性 -->
		<id column="teamid" property="id"/>
		<result column="tname" property="name"/>
		
		<!-- 关联属性的映射关系 -->
		<collection property="playerList" ofType="player">
			<id column="pid" property="id"/>
			<result column="pname" property="name"/>
		</collection>
	</resultMap>

	<select id="selectTeamById" resultMap="teamMap">
		select t.id teamid,t.name tname,p.id pid,p.name pname
		from t_team t,t_player p
		where t.id=p.tid and t.id=#{id}
	</select>
</mapper>

db.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/learnmybatis?useSSL=false
jdbc.user=root
jdbc.password=666666

log4j.properties

log4j.rootLogger=debug,console
#log4j.logger.com.monkey1024.dao.StudentDao=debug,concole
#\u63A7\u5236\u53F0\u9644\u52A0\u5668
log4j.appender.console = org.apache.log4j.ConsoleAppender
log4j.appender.console.Target = System.out
log4j.appender.console.layout = org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern = [%-5p][%d{yyyy-MM--dd HH:mm:ss}]%m%n

Player.java 

package com.monkey1024.bean;



/*
 * 篮球队员
 */
public class Player {	
	private int id;
	private String name;
	public Player(String name){
		this.name = name;
	}
	public Player(){
		
	}
	@Override
	public String toString() {
		return "Player [id=" + id + ", name=" + name + "]";
	}
	public int getId(){
		return id;
	}
	public void setId(int id){
		this.id = id;
	}
	public String getName(){
		return name;
	}
	public void setName(String name){
		this.name = name;
	}

}

Team.java

package com.monkey1024.bean;

import java.util.List;

/*
 * 篮球队
 */
public class Team {
	private int id;
	private String name;
	private List<Player> playerList;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	@Override
	public String toString() {
		return "Team [id=" + id + ", name=" + name + ", playerList=" + playerList + "]";
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public List<Player> getPlayerList() {
		return playerList;
	}
	public void setPlayerList(List<Player> playerList) {
		this.playerList = playerList;
	}
	
}

TeamDao.java

package com.monkey1024.dao;

import com.monkey1024.bean.Team;

public interface TeamDao {
	Team selectTeamById(int id);
}

MyBatisUtil.java

package com.monkey1024.util;

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;

/*
 * DCL鐨勫崟渚嬫ā寮�
 */
public class MyBatisUtil {
	// 鏃犻渶灏嗘瀯閫犳柟娉曠鏈夊寲锛屽洜涓鸿繖閲岄潰鍙淇濊瘉鍒涘缓涓�涓猄qlSessionFactory鐨勫璞�
	// private MyBatisUtil()
	private static volatile SqlSessionFactory sqlSessionFactory;

	public static SqlSession getSqlSession() {
		try {
			if (sqlSessionFactory == null) {
				// 璇诲彇涓婚厤缃枃浠�
				InputStream input = Resources.getResourceAsStream("mybatis.xml");
				synchronized (MyBatisUtil.class) {
					if (sqlSessionFactory == null) {
						sqlSessionFactory = new SqlSessionFactoryBuilder().build(input);
					}
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		//mybatis鑷姩鎻愪氦浜嬪姟
//		return sqlSessionFactory.openSession(true);
		return sqlSessionFactory.openSession();

	}
}

TeamTest01.java

package com.monkey1024.test;

import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.monkey1024.bean.Team;
import com.monkey1024.dao.TeamDao;
import com.monkey1024.util.MyBatisUtil;

public class TeamTest01 {
	private SqlSession sqlSession;
	private TeamDao teamDao;
	
	@Before
	public void init(){
		sqlSession = MyBatisUtil.getSqlSession();
		teamDao = sqlSession.getMapper(TeamDao.class);
	}
	
	@After 
	public void closeSession(){
		if(sqlSession!=null){
			sqlSession.close();
		}
	}
	
	@Test
	public void selectTeamById(){
		Team team = teamDao.selectTeamById(1);
		System.out.println(team);
	}
	
}