三、基于注解入门实例
1、定义操作 user 表的注解接口 UserMapper.java
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package com.ys.annocation;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 com.ys.po.User;public interface UserMapper { //根据 id 查询 user 表数据 @Select("select * from user where id = #{id}") public User selectUserById(int id) throws Exception; //向 user 表插入一条数据 @Insert("insert into user(username,sex,birthday,address) value(#{username},#{sex},#{birthday},#{address})") public void insertUser(User user) throws Exception; //根据 id 修改 user 表数据 @Update("update user set username=#{username},sex=#{sex} where id=#{id}") public void updateUserById(User user) throws Exception; //根据 id 删除 user 表数据 @Delete("delete from user where id=#{id}") public void deleteUserById(int id) throws Exception; } |
2、向 mybatis-configuration.xml 配置文件中注册 UserMapper.java 文件
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<mappers> <mapper class="com.ys.annocation.UserMapper"/></mappers> |
3、创建测试类
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package com.ys.test;import java.io.InputStream;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.ys.annocation.UserMapper;import com.ys.po.User;public class UserAnnocationTest { //定义 SqlSession SqlSession session =null; @Before public void init(){ //定义mybatis全局配置文件 String resource = "mybatis-configuration.xml"; //加载 mybatis 全局配置文件 InputStream inputStream = CRUDTest.class.getClassLoader() .getResourceAsStream(resource); //构建sqlSession的工厂 SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputStream); //根据 sqlSessionFactory 产生 session session = sessionFactory.openSession(); } //注解的增删改查方法测试 @Test public void testAnncationCRUD() throws Exception{ //根据session获取 UserMapper接口 UserMapper userMapper = session.getMapper(UserMapper.class); //调用selectUserById()方法 User user = userMapper.selectUserById(1); System.out.println(user); //调用 insertUser() 方法 User user1 = new User(); user1.setUsername("aliks"); user1.setSex("不详"); userMapper.insertUser(user1); //调用 updateUserById() 方法 User user2 = new User(); user2.setId(6); user2.setUsername("lbj"); userMapper.updateUserById(user2); //调用 () 方法 userMapper.deleteUserById(6); session.commit(); session.close(); }} |
注意：注解配置我们不需要 userMapper.xml 文件了
