使用MyBatis对表执行CRUD操作

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 3 <!-- 为这个mapper指定一个唯一的namespace，namespace的值习惯上设置成包名+sql映射文件名，这样就能够保证namespace的值是唯一的
 4 例如namespace="me.gacl.mapping.userMapper"就是me.gacl.mapping(包名)+userMapper(userMapper.xml文件去除后缀)
 5  -->
 6 <mapper namespace="me.gacl.mapping.userMapper">
 7     <!-- 在select标签中编写查询的SQL语句， 设置select标签的id属性为getUser，id属性值必须是唯一的，不能够重复
 8     使用parameterType属性指明查询时使用的参数类型，resultType属性指明查询返回的结果集类型
 9     resultType="me.gacl.domain.User"就表示将查询结果封装成一个User类的对象返回
10     User类就是users表所对应的实体类
11     -->
12     <!-- 
13         根据id查询得到一个user对象
14      -->
15     <select id="getUser" parameterType="int" 
16         resultType="me.gacl.domain.User">
17         select * from users where id=#{id}
18     </select>
19     
20     <!-- 创建用户(Create) -->
21     <insert id="addUser" parameterType="me.gacl.domain.User">
22         insert into users(name,age) values(#{name},#{age})
23     </insert>
24     
25     <!-- 删除用户(Remove) -->
26     <delete id="deleteUser" parameterType="int">
27         delete from users where id=#{id}
28     </delete>
29     
30     <!-- 修改用户(Update) -->
31     <update id="updateUser" parameterType="me.gacl.domain.User">
32         update users set name=#{name},age=#{age} where id=#{id}
33     </update>
34     
35     <!-- 查询全部用户-->
36     <select id="getAllUsers" resultType="me.gacl.domain.User">
37         select * from users
38     </select>
39     
40 </mapper>

 1 package me.gacl.test;
 2 
 3 import java.util.List;
 4 import me.gacl.domain.User;
 5 import me.gacl.util.MyBatisUtil;
 6 import org.apache.ibatis.session.SqlSession;
 7 import org.junit.Test;
 8 
 9 public class TestCRUDByXmlMapper {
10 
11     @Test
12     public void testAdd(){
13         //SqlSession sqlSession = MyBatisUtil.getSqlSession(false);
14         SqlSession sqlSession = MyBatisUtil.getSqlSession(true);
15         /**
16          * 映射sql的标识字符串，
17          * me.gacl.mapping.userMapper是userMapper.xml文件中mapper标签的namespace属性的值，
18          * addUser是insert标签的id属性值，通过insert标签的id属性值就可以找到要执行的SQL
19          */
20         String statement = "me.gacl.mapping.userMapper.addUser";//映射sql的标识字符串
21         User user = new User();
22         user.setName("用户Isaac");
23         user.setAge(20);
24         //执行插入操作
25         int retResult = sqlSession.insert(statement,user);
26         //手动提交事务
27         //sqlSession.commit();
28         //使用SqlSession执行完SQL之后需要关闭SqlSession
29         sqlSession.close();
30         System.out.println(retResult);
31     }
32     
33     @Test
34     public void testUpdate(){
35         SqlSession sqlSession = MyBatisUtil.getSqlSession(true);
36         /**
37          * 映射sql的标识字符串，
38          * me.gacl.mapping.userMapper是userMapper.xml文件中mapper标签的namespace属性的值，
39          * updateUser是update标签的id属性值，通过update标签的id属性值就可以找到要执行的SQL
40          */
41         String statement = "me.gacl.mapping.userMapper.updateUser";//映射sql的标识字符串
42         User user = new User();
43         user.setId(3);
44         user.setName("Isaac");
45         user.setAge(25);
46         //执行修改操作
47         int retResult = sqlSession.update(statement,user);
48         //使用SqlSession执行完SQL之后需要关闭SqlSession
49         sqlSession.close();
50         System.out.println(retResult);
51     }
52     
53     @Test
54     public void testDelete(){
55         SqlSession sqlSession = MyBatisUtil.getSqlSession(true);
56         /**
57          * 映射sql的标识字符串，
58          * me.gacl.mapping.userMapper是userMapper.xml文件中mapper标签的namespace属性的值，
59          * deleteUser是delete标签的id属性值，通过delete标签的id属性值就可以找到要执行的SQL
60          */
61         String statement = "me.gacl.mapping.userMapper.deleteUser";//映射sql的标识字符串
62         //执行删除操作
63         int retResult = sqlSession.delete(statement,5);
64         //使用SqlSession执行完SQL之后需要关闭SqlSession
65         sqlSession.close();
66         System.out.println(retResult);
67     }
68     
69     @Test
70     public void testGetAll(){
71         SqlSession sqlSession = MyBatisUtil.getSqlSession();
72         /**
73          * 映射sql的标识字符串，
74          * me.gacl.mapping.userMapper是userMapper.xml文件中mapper标签的namespace属性的值，
75          * getAllUsers是select标签的id属性值，通过select标签的id属性值就可以找到要执行的SQL
76          */
77         String statement = "me.gacl.mapping.userMapper.getAllUsers";//映射sql的标识字符串
78         //执行查询操作，将查询结果自动封装成List<User>返回
79         List<User> lstUsers = sqlSession.selectList(statement);
80         //使用SqlSession执行完SQL之后需要关闭SqlSession
81         sqlSession.close();
82         System.out.println(lstUsers);
83     }
84 }

 1 package me.gacl.mapping;
 2 
 3 import java.util.List;
 4 import me.gacl.domain.User;
 5 import org.apache.ibatis.annotations.Delete;
 6 import org.apache.ibatis.annotations.Insert;
 7 import org.apache.ibatis.annotations.Select;
 8 import org.apache.ibatis.annotations.Update;
 9 
10 /**
11  * @author gacl
12  * 定义sql映射的接口，使用注解指明方法要执行的SQL
13  */
14 public interface UserMapperI {
15 
16     //使用@Insert注解指明add方法要执行的SQL
17     @Insert("insert into users(name, age) values(#{name}, #{age})")
18     public int add(User user);
19     
20     //使用@Delete注解指明deleteById方法要执行的SQL
21     @Delete("delete from users where id=#{id}")
22     public int deleteById(int id);
23     
24     //使用@Update注解指明update方法要执行的SQL
25     @Update("update users set name=#{name},age=#{age} where id=#{id}")
26     public int update(User user);
27     
28     //使用@Select注解指明getById方法要执行的SQL
29     @Select("select * from users where id=#{id}")
30     public User getById(int id);
31     
32     //使用@Select注解指明getAll方法要执行的SQL
33     @Select("select * from users")
34     public List<User> getAll();
35 }

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
 3 <configuration>
 4     <environments default="development">
 5         <environment id="development">
 6             <transactionManager type="JDBC" />
 7             <!-- 配置数据库连接信息 -->
 8             <dataSource type="POOLED">
 9                 <property name="driver" value="com.mysql.jdbc.Driver" />
10                 <property name="url" value="jdbc:mysql://localhost:3306/mybatis" />
11                 <property name="username" value="root" />
12                 <property name="password" value="XDP" />
13             </dataSource>
14         </environment>
15     </environments>
16     
17     <mappers>
18         <!-- 注册userMapper.xml文件， 
19         userMapper.xml位于me.gacl.mapping这个包下，所以resource写成me/gacl/mapping/userMapper.xml-->
20         <mapper resource="me/gacl/mapping/userMapper.xml"/>
21         <!-- 注册UserMapper映射接口-->
22         <mapper class="me.gacl.mapping.UserMapperI"/>
23     </mappers>
24     
25 </configuration>

 1 package me.gacl.test;
 2 
 3 import java.util.List;
 4 import me.gacl.domain.User;
 5 import me.gacl.mapping.UserMapperI;
 6 import me.gacl.util.MyBatisUtil;
 7 import org.apache.ibatis.session.SqlSession;
 8 import org.junit.Test;
 9 
10 public class TestCRUDByAnnotationMapper {
11 
12     @Test
13     public void testAdd(){
14         SqlSession sqlSession = MyBatisUtil.getSqlSession(true);
15         //得到UserMapperI接口的实现类对象，UserMapperI接口的实现类对象由sqlSession.getMapper(UserMapperI.class)动态构建出来
16         UserMapperI mapper = sqlSession.getMapper(UserMapperI.class);
17         User user = new User();
18         user.setName("用户xdp");
19         user.setAge(20);
20         int add = mapper.add(user);
21         //使用SqlSession执行完SQL之后需要关闭SqlSession
22         sqlSession.close();
23         System.out.println(add);
24     }
25     
26     @Test
27     public void testUpdate(){
28         SqlSession sqlSession = MyBatisUtil.getSqlSession(true);
29         //得到UserMapperI接口的实现类对象，UserMapperI接口的实现类对象由sqlSession.getMapper(UserMapperI.class)动态构建出来
30         UserMapperI mapper = sqlSession.getMapper(UserMapperI.class);
31         User user = new User();
32         user.setId(3);
33         user.setName("Isaac_xdp");
34         user.setAge(26);
35         //执行修改操作
36         int retResult = mapper.update(user);
37         //使用SqlSession执行完SQL之后需要关闭SqlSession
38         sqlSession.close();
39         System.out.println(retResult);
40     }
41     
42     @Test
43     public void testDelete(){
44         SqlSession sqlSession = MyBatisUtil.getSqlSession(true);
45         //得到UserMapperI接口的实现类对象，UserMapperI接口的实现类对象由sqlSession.getMapper(UserMapperI.class)动态构建出来
46         UserMapperI mapper = sqlSession.getMapper(UserMapperI.class);
47         //执行删除操作
48         int retResult = mapper.deleteById(7);
49         //使用SqlSession执行完SQL之后需要关闭SqlSession
50         sqlSession.close();
51         System.out.println(retResult);
52     }
53     
54     @Test
55     public void testGetUser(){
56         SqlSession sqlSession = MyBatisUtil.getSqlSession();
57         //得到UserMapperI接口的实现类对象，UserMapperI接口的实现类对象由sqlSession.getMapper(UserMapperI.class)动态构建出来
58         UserMapperI mapper = sqlSession.getMapper(UserMapperI.class);
59         //执行查询操作，将查询结果自动封装成User返回
60         User user = mapper.getById(8);
61         //使用SqlSession执行完SQL之后需要关闭SqlSession
62         sqlSession.close();
63         System.out.println(user);
64     }
65     
66     @Test
67     public void testGetAll(){
68         SqlSession sqlSession = MyBatisUtil.getSqlSession();
69         //得到UserMapperI接口的实现类对象，UserMapperI接口的实现类对象由sqlSession.getMapper(UserMapperI.class)动态构建出来
70         UserMapperI mapper = sqlSession.getMapper(UserMapperI.class);
71         //执行查询操作，将查询结果自动封装成List<User>返回
72         List<User> lstUsers = mapper.getAll();
73         //使用SqlSession执行完SQL之后需要关闭SqlSession
74         sqlSession.close();
75         System.out.println(lstUsers);
76     }
77 }

 1 package me.gacl.util;
 2 
 3 import java.io.InputStream;
 4 
 5 import org.apache.ibatis.session.SqlSession;
 6 import org.apache.ibatis.session.SqlSessionFactory;
 7 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 8 
 9 public class MyBatisUtil {
10 
11     /**
12      * 获取SqlSessionFactory
13      * @return SqlSessionFactory
14      */
15     public static SqlSessionFactory getSqlSessionFactory() {
16         String resource = "conf.xml";
17         InputStream is = MyBatisUtil.class.getClassLoader().getResourceAsStream(resource);
18         SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);
19         return factory;
20     }
21     
22     /**
23      * 获取SqlSession
24      * @return SqlSession
25      */
26     public static SqlSession getSqlSession() {
27         return getSqlSessionFactory().openSession();
28     }
29     
30     /**
31      * 获取SqlSession
32      * @param isAutoCommit 
33      *         true 表示创建的SqlSession对象在执行完SQL之后会自动提交事务
34      *         false 表示创建的SqlSession对象在执行完SQL之后不会自动提交事务，这时就需要我们手动调用sqlSession.commit()提交事务
35      * @return SqlSession
36      */
37     public static SqlSession getSqlSession(boolean isAutoCommit) {
38         return getSqlSessionFactory().openSession(isAutoCommit);
39     }
40 }