第三节基于注解实现CURD

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本文介绍了一个使用MyBatis实现用户信息增删改查功能的Java示例。示例中定义了User类，包含基本属性及getter和setter方法；UserDao接口，定义了用户数据操作的方法，并通过MyBatis注解实现SQL语句；Test类用于测试增删改查功能。通过配置文件mybatis-config.xml将UserDao接口映射为实际的数据库操作。

User.java

package cn.edu.scnu.entity;

public class User {
    private Integer id;
    private String name;
    private int age;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

UserDao.java

package cn.edu.scnu.dao;

import cn.edu.scnu.entity.User;
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;

public interface UserDao {
    @Insert("insert into users(id,username,age) values(#{id},#{name},#{age})")
    public int saveUser(User user);
    @Delete("delete from users where id=#{id}")
    public int deleteUser(Integer id);
    @Update("update users set username=#{name},age=#{age} where id=#{id}")
    public int updateUser(User user);
    @Select("select * from users where id=#{id}")
    public User findOne(Integer id);
    @Select("select * from users")
    public List<User> findAll();
}

Test.java

package cn.edu.scnu;

import cn.edu.scnu.dao.UserDao;
import cn.edu.scnu.entity.User;
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.Test;

import java.io.IOException;
import java.io.InputStream;

public class Test2 {
    private SqlSessionFactory sqlSessionFactory;
    private SqlSession sqlSession;

    @Before
    public void init(){
        String resource = "mybatis-config.xml";
        try{
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
            sqlSession = sqlSessionFactory.openSession();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    @After
    public void destroy(){
        sqlSession.commit();
        sqlSession.close();
    }

    @Test
    public void addUser(){
        User user = new User();
        user.setId(2);
        user.setName("乔峰");
        user.setAge(34);

        UserDao userDao = sqlSession.getMapper(UserDao.class);
        int result = userDao.saveUser(user);
    }
}

mybatis-config.xml

<mapper class="cn.edu.scnu.dao.UserDao"/>

第三节 基于注解实现CURD

第三节基于注解实现CURD