mybatis之注解方式实现

* 使用mybatis举例，使用注解方式实现
* 不需要针对UserMapperI接口去编写具体的实现类代码，这个具体的实现类由MyBatis帮我们动态构建出来，我们只需要直接拿来使用即可。
* 1、导入jar包：mybatis和mysql-connector
* 2、mybatis配置文件：mybatis-config.xml，加载Mapper接口路径
* 3、编写JavaBean类：UserBean
* 4、编写执行sql接口
* 5、编写测试类进行测试

mybatis-config-zhujie.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>
     <!--从外部配置文件导入jdbc信息-->
     <properties resource="jdbc.properties"></properties>

     <environments default="development">
         <environment id="development">
             <transactionManager type="JDBC"/>
             <dataSource type="POOLED">
                 <property name="driver" value="${driver}"/>
                 <property name="url" value="${url}"/>
                 <property name="username" value="${username}"/>
                 <property name="password" value="${password}"/>
             </dataSource>
         </environment>
     </environments>

     <!--指定映射资源文件-->
     <mappers>
         <mapper class="zhujie.UserMapperInterface"></mapper>

     </mappers>
 </configuration>

UserMapperInterface.java

 package zhujie;

 import bean.UserSalary;
 import first.UserBean;
 import org.apache.ibatis.annotations.Delete;
 import org.apache.ibatis.annotations.Insert;
 import org.apache.ibatis.annotations.Select;
 import org.apache.ibatis.annotations.Update;

 import java.util.List;

 /*
 * 使用mybatis举例，使用注解方式实现
 * 不需要针对UserMapperI接口去编写具体的实现类代码，这个具体的实现类由MyBatis帮我们动态构建出来，我们只需要直接拿来使用即可。
 * 1、导入jar包：mybatis和mysql-connector
 * 2、mybatis配置文件：mybatis-config.xml，加载Mapper接口路径
 * 3、编写JavaBean类：UserBean
 * 4、编写执行sql接口
 * 5、编写测试类进行测试，自动实例化，调用方法
 * */
 public interface UserMapperInterface {

     //    UserBean
     @Select("select * from user where id = #{id}")
     public UserBean selectOneUser(int id);

     @Select("select * from user")
     public List<UserBean> selectAllUser();

     @Insert("insert into user (id, name, age) values (#{id} ,#{name}, #{age})")
     public int insertUser(UserBean userBean);

     @Update("update user set name=#{name} where id=#{id}")
     public int updateUser(UserBean userBean);

     @Delete("delete from user where id=#{id}")
     public int deleteById(int id);

     @Delete("delete from user where id=#{id}")
     public int deleteByUserBean(UserBean userBean);

     // 使用User和Salary表联合查询
     @Select("select u.id, u.name, u.age, s.salary from user u, salary s where u.name = s.name and u.name = #{name}")
     public UserSalary selectOneUserSalary(String name);

 }

TestZhuJie.java

 package zhujie;

 import bean.UserSalary;
 import first.UserBean;
 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.After;
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;

 import java.io.IOException;
 import java.io.InputStream;
 import java.util.List;

 /*
 * 使用mybatis举例，使用注解方式实现
 * 不需要针对UserMapperI接口去编写具体的实现类代码，这个具体的实现类由MyBatis帮我们动态构建出来，我们只需要直接拿来使用即可。
 * 1、导入jar包：mybatis和mysql-connector
 * 2、mybatis配置文件：mybatis-config.xml，加载Mapper接口路径
 * 3、编写JavaBean类：UserBean
 * 4、编写执行sql接口
 * 5、编写测试类进行测试
 * */
 public class TestZhuJie {
     String resource = "mybatis-config-zhujie.xml";
     SqlSessionFactory sqlSessionFactory = null;
     SqlSession session = null;

     @Before
     public void before() {
 //        System.out.println("Before");
         try {
             InputStream inputStream = Resources.getResourceAsStream(resource);
 //            创建工厂
             sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
 //            创建session对象
             session = sqlSessionFactory.openSession();

         } catch (IOException e) {
             e.printStackTrace();
         }
     }

     @After
     public void close() {
         session.close();
 //        System.out.println("After");
     }

     @Test
     public void testSelectOneUser() {
 //        接口自动实例化
         UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
 //        执行sql
         UserBean userBean = userMapperInterface.selectOneUser(1);
         System.out.println(userBean);
     }

 //    批量查询
     @Test
     public void testSelectAllUser() {
 //        接口自动实例化
         UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
 //        执行sql
         List<UserBean> listUserBean = userMapperInterface.selectAllUser();
         System.out.println("记录个数：" + listUserBean.size());
         System.out.println(listUserBean);
     }

     @Ignore
     @Test
     public void testInsertUser() {
         UserBean userBean = new UserBean("CoCo2", "50");
         UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
         int n = userMapperInterface.insertUser(userBean);
 //        提交
         session.commit();
         System.out.println("插入数据成功：" + userBean);
     }

     @Ignore
     @Test
     public void testUpdateUser() {
         UserBean userBean = new UserBean(2, "Tom44", "40");
         UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
         userMapperInterface.updateUser(userBean);
         session.commit();
         System.out.println("修改数据成功：" + userBean);
     }

     @Ignore
     @Test
     public void testDeleteUser() {
         UserBean userBean = new UserBean(15, "XXX", "40");
         UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
         int n = userMapperInterface.deleteByUserBean(userBean);
         session.commit();
         System.out.println("删除数据成功：" + userBean);
         System.out.println("操作成功记录数：" + n);
     }

     @Test
     public void testSelectOneUserSalary() {
 //        接口自动实例化
         UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
 //        执行sql
         UserSalary userSalary = userMapperInterface.selectOneUserSalary("Tom");
         System.out.println(userSalary);
     }

 }