mybatis实现表与对象的关联关系_动力节点Java学院整理

<dependencies>     <dependency>       <groupId>org.mybatis</groupId>       <artifactId>mybatis</artifactId>       <version>3.2.7</version>     </dependency>     <dependency>       <groupId>junit</groupId>       <artifactId>junit</artifactId>       <version>4.9</version>       <scope>test</scope>     </dependency>     <dependency>       <groupId>org.apache.derby</groupId>       <artifactId>derby</artifactId>       <version>10.10.2.0</version>     </dependency>     <dependency>       <groupId>org.apache.derby</groupId>       <artifactId>derbyclient</artifactId>       <version>10.10.2.0</version>     </dependency>   </dependencies> 

CREATE TABLE USER_TEST_TB_RELATIONSHIP( USER_ID INT PRIMARY KEY,   USER_USERNAME VARCHAR(20) NOT NULL,   USER_PASSWORD VARCHAR(20) NOT NULL,   USER_NICKNAME VARCHAR(20) NOT NULL   );  INSERT INTO USER_TEST_TB_RELATIONSHIP(USER_ID,USER_USERNAME,USER_PASSWORD,USER_NICKNAME) SELECT ID,USERNAME,PASSWORD,NICKNAME FROM USER_TEST_TB; 

<?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>   <properties>     <property name="driver" value="org.apache.derby.jdbc.ClientDriver" />     <property name="url"       value="jdbc:derby://localhost:1527/bjpowernode;create=true" />   </properties>   <environments default="development">     <environment id="development">       <transactionManager type="JDBC" />       <dataSource type="POOLED">         <property name="driver" value="${driver}" />         <property name="url" value="${url}" />       </dataSource>     </environment>   </environments>   <mappers>     <mapper resource="com/bjpowernode/practice/UserMapper.xml" />  </mappers> </configuration>  

package com.bjpowernode.practice; public class User {   private Integer id;   private String username;   private String password;   private String nickname;   public Integer getId()   {     return id;   }   public void setId(Integer id)   {     this.id = id;   }   public String getUsername()   {     return username;   }   public void setUsername(String username)   {     this.username = username;   }   public String getPassword()   {     return password;   }   public void setPassword(String password)   {     this.password = password;   }   public String getNickname()   {     return nickname;   }   public void setNickname(String nickname)   {     this.nickname = nickname;   } } 

<?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.bjpowernode.practice.UserMapper">    <!-- 对象属性和表字段的对应 -->   <resultMap id="userResultMap" type="com.bjpowernode.practice.User">     <result property="id" column="USER_ID"/>     <result property="username" column="USER_USERNAME"/>     <result property="password" column="USER_PASSWORD"/>     <result property="nickname" column="USER_NICKNAME"/>   </resultMap>      <select id="getUser" resultMap="userResultMap">     select *     from USER_TEST_TB_RELATIONSHIP   </select> </mapper> 

package com.bjpowernode.practice;  import java.util.List;  public interface UserMapper {   public List<User> getUser(); } 

package com.bjpowernode.practice; import java.io.InputStream; import java.text.MessageFormat; import java.util.List; 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; public class TestMyBatis {   private String source;   private InputStream inputStream;   private SqlSessionFactory sqlSessionFactory;   @Before   public void setUp()   {     /**      * 准备Mybatis运行环境      */     source = "test-mybatis-configuration.xml";     inputStream = TestMyBatis.class.getClassLoader().getResourceAsStream(source);     sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);   }   @Test   public void testGet()   {     try     {       // 获取Session连接       SqlSession session = sqlSessionFactory.openSession();       // 获取Mapper       UserMapper userMapper = session.getMapper(UserMapper.class);       // 显示User信息       System.out.println("Test Get start...");       this.printUsers(userMapper.getUser());       System.out.println("Test Get finished...");     }     catch (Exception e)     {       e.printStackTrace();     }   }   /**    *    * 打印用户信息到控制台    *    * @param users    */   private void printUsers(final List<User> users)   {     int count = 0;     for (User user : users)     {       System.out.println(MessageFormat.format("==User[{0}]=================", ++count));       System.out.println("User Id: " + user.getId());       System.out.println("User UserName: " + user.getUsername());       System.out.println("User Password: " + user.getPassword());       System.out.println("User nickname: " + user.getNickname());     }   } }