Mybatis注解开发单表CRUD

Mybatis注解开发单表CRUD

---

mybatis注解开发和xml开发不可兼容，要么全部使用注解，要么全部使用xml，个人建议注解，简单。

当实体类属性名称和数据库表属性名称一致时：无需配置Results

实体类User

 package com.itheima.domain;
 ​
 import java.io.Serializable;
 import java.util.Date;
 import java.util.List;
 ​
 /**
  * @Author: lijiahao
  * @Description:
  * @Data: Create in 21:37 2020/2/22
  * @Modified By:
  */
 public class User implements Serializable {
     private Integer id;
     private String username;
     private Date birthday;
     private String sex;
     private String address;
 ​
     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 Date getBirthday() {
         return birthday;
     }
 ​
     public void setBirthday(Date birthday) {
         this.birthday = birthday;
     }
 ​
     public String getSex() {
         return sex;
     }
 ​
     public void setSex(String sex) {
         this.sex = sex;
     }
 ​
     public String getAddress() {
         return address;
     }
 ​
     public void setAddress(String address) {
         this.address = address;
     }
 ​
     @Override
     public String toString() {
         return "User{" +
                 "id=" + id +
                 ", username='" + username + '\'' +
                 ", birthday=" + birthday +
                 ", sex='" + sex + '\'' +
                 ", address='" + address + '\'' +
                 '}';
     }
 }
 ​

接口IUserDao

 package com.itheima.dao;
 ​
 import com.itheima.domain.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.beans.IntrospectionException;
 import java.util.List;
 ​
 /**
  * @Author: lijiahao
  * @Description: 用户的持久层接口
  * @Data: Create in 21:42 2020/2/22
  * @Modified By:
  */
 public interface IUserDao {
 ​
     //查询所有用户，同时获取到用户下所有账户的信息
     @Select("select * from user")
     List<User> findAll();
 ​
     @Insert("Insert into user (username,address,sex,birthday) values (#{username},#{address},#{sex},#{birthday})")
     void  saveUser(User user);
 ​
     @Update("update user set username=#{username},address=#{address},sex=#{sex},birthday=#{birthday} where id = #{id}")
     void updateUser(User user);
 ​
     @Delete("delete from user where id = #{id}")
     void deleteUser(Integer integer);
 ​
     @Select("select * from user where id = #{id}")
     User findById(Integer integer);
 ​
     @Select("Select * from user where username like #{username}")
  /*   @Select("Select * from user where username like '%${value}%'")*/
     List<User> findUserByName(String username);
 ​
     @Select("select count(*) from user")
     int findTotalUser();
 }
 ​

配置文件

主配置文件

 <?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">
 ​
 <!--mybatis的主配置文件-->
 <configuration>
 ​
     <properties resource="jdbcConfig.properties"/>
 ​
     <!--配置别名 类名就是别名，不区分大小写-->
     <typeAliases>
         <package name="com.itheima.domain" ></package>
     </typeAliases>
 ​
     <!--配置环境-->
     <environments default="mysql">
         <!--配置mysql的环境-->
         <environment id="mysql">
             <!--配置事务的类型-->
             <transactionManager type="JDBC"></transactionManager>
             <!--配置数据源（连接池）-->
             <dataSource type="POOLED">
                 <!--配置数据库的四个基本信息-->
                 <property name="driver" value="${jdbc.driver}" />
                 <property name="url" value="${jdbc.url}"/>
                 <property name="username" value="${jdbc.username}" />
                 <property name="password" value="${jdbc.password}" />
             </dataSource>
         </environment>
     </environments>
 ​
     <!--指定dao接口所在位置-->
     <mappers>
         <package name="com.itheima.dao"></package>
     </mappers>
 </configuration>

连接池

 jdbc.driver=com.mysql.cj.jdbc.Driver
 jdbc.url=jdbc:mysql://localhost:3306/eesy?serverTimezone=Asia/Shanghai&characterEncoding=utf8&useSSL=false
 jdbc.username=root
 jdbc.password=123456

日志

 ### 设置###
 log4j.rootLogger = debug,CONSOLE,LOGFILE
 ​
 log4j.logger.org.apache.axis.enterprise=FATAL,CONSOLE
 ​
 log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
 log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
 log4j.appender.CONSOLE.layout.ConversionPattern=%d{ISO8601} %-6r [%15.15t] %-5p %30.30c %x - %m\n
 ​
 ### 输出ERROR 级别以上的日志到=E://logs/error.log ###
 log4j.appender.LOGFILE = org.apache.log4j.FileAppender
 log4j.appender.LOGFILE.FILE = F://logs/error.log
 log4j.appender.LOGFILE.Append = true
 log4j.appender.LOGFILE.layout = org.apache.log4j.PatternLayout
 log4j.appender.LOGFILE.layout.ConversionPattern = %d{ISO8601} %-6r [%15.15t] %-5p %30.30c %x - %m\n

---

测试类

 package com.itheima;
 ​
 import com.itheima.dao.IUserDao;
 import com.itheima.domain.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;
 import java.util.Date;
 import java.util.List;
 ​
 /**
  * @Author: lijiahao
  * @Description:
  * @Data: Create in 22:56 2020/2/22
  * @Modified By:
  */
 public class AnnotationCRUDTest {
     private InputStream in;
     private SqlSession sqlSession;
     private IUserDao iUserDao;
     private SqlSessionFactory sqlSessionFactory;
 ​
     @Before
     public void init() throws Exception {
         in = Resources.getResourceAsStream("SqlMapConfig.xml");
         sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
         sqlSession = sqlSessionFactory.openSession();
         iUserDao = sqlSession.getMapper(IUserDao.class);
     }
 ​
     @After
     public void destroy() throws IOException {
         sqlSession.commit();
         sqlSession.close();
         in.close();
     }
 ​
     @Test
     public void testSave(){
         User user = new User();
         user.setUsername("李家豪");
         user.setAddress("郑州市");
 ​
         iUserDao.saveUser(user);
     }
 ​
     @Test
     public void testUpdate(){
         User user = new User();
         user.setId(47);
         user.setUsername("李家豪");
         user.setAddress("郑州市");
         user.setSex("女");
         user.setBirthday(new Date());
 ​
         iUserDao.updateUser(user);
         System.out.println(user);
     }
 ​
     @Test
     public void testDelete(){
         iUserDao.deleteUser(47);
     }
 ​
     @Test
     public void testFindById(){
         User user = iUserDao.findById(57);
         System.out.println(user);
     }
 ​
     @Test
     public void testFindUserByName(){
         List<User> users = iUserDao.findUserByName("%王%");
         //List<User> users = iUserDao.findUserByName("王");
         for(User user : users)
         System.out.println(user);
     }
 ​
     @Test
     public void testFindTotal(){
         int count = iUserDao.findTotalUser();
         System.out.println(count);
     }
 }

---

当实体类属性名称和数据库表属性名称一致时：需配置Results

接口IUserDao

 package com.itheima.dao;
 ​
 import com.itheima.domain.User;
 import org.apache.ibatis.annotations.*;
 ​
 import java.beans.IntrospectionException;
 import java.util.List;
 ​
 /**
  * @Author: lijiahao
  * @Description: 用户的持久层接口
  * @Data: Create in 21:42 2020/2/22
  * @Modified By:
  */
 public interface IUserDao {
 ​
     //查询所有用户，同时获取到用户下所有账户的信息
     @Select("select * from user")
     //当实体类的属性和数据库的属性名称不一致时，需要配置对应关系，id为该Results的唯一标识
     @Results(id = "userMap", value={
             @Result(id=true,column = "id",property = "userId"),
             @Result(column = "username",property = "userName"),
             @Result(column = "sex",property = "userSex"),
             @Result(column = "address",property = "userAddress"),
             @Result(column = "birthday",property = "userBirthday"),
     })
     List<User> findAll();
 ​
     @Insert("Insert into user (username,address,sex,birthday) values (#{username},#{address},#{sex},#{birthday})")
     void  saveUser(User user);
 ​
     @Update("update user set username=#{username},address=#{address},sex=#{sex},birthday=#{birthday} where id = #{id}")
     void updateUser(User user);
 ​
     @Delete("delete from user where id = #{id}")
     void deleteUser(Integer integer);
 ​
     @Select("select * from user where id = #{id}")
     @ResultMap(value = {"userMap"})
     User findById(Integer integer);
 ​
     @Select("Select * from user where username like #{username}")
     @ResultMap(value = {"userMap"})
     List<User> findUserByName(String username);
 ​
 }
 ​

测试

 package com.itheima;
 ​
 import com.itheima.dao.IUserDao;
 import com.itheima.domain.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;
 import java.util.Date;
 import java.util.List;
 ​
 /**
  * @Author: lijiahao
  * @Description:
  * @Data: Create in 22:56 2020/2/22
  * @Modified By:
  */
 public class AnnotationCRUDTest {
     private InputStream in;
     private SqlSession sqlSession;
     private IUserDao iUserDao;
     private SqlSessionFactory sqlSessionFactory;
 ​
     @Before
     public void init() throws Exception {
         in = Resources.getResourceAsStream("SqlMapConfig.xml");
         sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
         sqlSession = sqlSessionFactory.openSession();
         iUserDao = sqlSession.getMapper(IUserDao.class);
     }
 ​
     @After
     public void destroy() throws IOException {
         sqlSession.commit();
         sqlSession.close();
         in.close();
     }
 ​
     @Test
     public void testFindAll(){
         List<User> users = iUserDao.findAll();
         for(User user : users)
             System.out.println(user);
     }
 ​
     @Test
     public void testFindById(){
         User user = iUserDao.findById(57);
         System.out.println(user);
     }
 ​
     @Test
     public void testFindUserByName(){
         List<User> users = iUserDao.findUserByName("%王%");
         //List<User> users = iUserDao.findUserByName("王");
         for(User user : users)
         System.out.println(user);
     }
 ​
 }