MyBatis注解之增删查改

朴灿烈づ我的快乐病毒、 2021-07-24 19:24 444阅读 0赞

**一 领域模型**

package org.fkit.domain;
    import java.io.Serializable;
    /**
    * CREATE TABLE `tb_user` (
      `id` INT(11) NOT NULL AUTO_INCREMENT,
      `name` VARCHAR(18) DEFAULT NULL,
      `sex` CHAR(2) DEFAULT NULL,
      `age` INT(11) DEFAULT NULL,
      PRIMARY KEY  (`id`)
    )
    */
    public class User implements Serializable{
         
         private static final long serialVersionUID = 1L;
         
         private Integer id;
         private String name;
         private String sex;
         private Integer age;
         
         public User() {
               super();
               // TODO Auto-generated constructor stub
         }
         
         public User( String name, String sex, Integer age) {
               super();
               this.name = name;
               this.sex = sex;
               this.age = 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 String getSex() {
               return sex;
         }
         public void setSex(String sex) {
               this.sex = sex;
         }
         public Integer getAge() {
               return age;
         }
         public void setAge(Integer age) {
               this.age = age;
         }
         @Override
         public String toString() {
               return "User [id=" + id + ", name=" + name + ", sex="  + sex + ", age="
                         + age + "]";
         }
         
         
    }

**二 会话工厂**

package org.fkit.factory;
    
    import java.io.InputStream;
    
    import org.apache.ibatis.io.Resources;
    import org.apache.ibatis.session.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.apache.ibatis.session.SqlSessionFactoryBuilder;
    
    public class FKSqlSessionFactory {
        
        private static SqlSessionFactory sqlSessionFactory = null;
        
        // 初始化创建SqlSessionFactory对象
        static{
            try (// 读取mybatis-config.xml文件
                    InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
                ){
                sqlSessionFactory = new SqlSessionFactoryBuilder()
                        .build(is);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        
        // 获取SqlSession对象的静态方法
        public static SqlSession getSqlSession(){
            return sqlSessionFactory.openSession();
        }
    
        // 获取SqlSessionFactory的静态方法
        public static SqlSessionFactory getSqlSessionFactory() {
            return sqlSessionFactory;
        }
    
    }

**三 mapper**

package org.fkit.mapper;
    
    import java.util.List;
    
    import org.apache.ibatis.annotations.Delete;
    import org.apache.ibatis.annotations.Insert;
    import org.apache.ibatis.annotations.Options;
    import org.apache.ibatis.annotations.Param;
    import org.apache.ibatis.annotations.Result;
    import org.apache.ibatis.annotations.Results;
    import org.apache.ibatis.annotations.Select;
    import org.apache.ibatis.annotations.Update;
    import org.fkit.domain.User;
    
    public interface UserMapper {
        
        @Insert("INSERT INTO TB_USER(name,sex,age) VALUES(#{name},#{sex},#{age})")
        @Options(useGeneratedKeys=true,keyProperty="id")
    //    @SelectKey(before=false,keyProperty="id",resultType=Integer.class,
    //    statement="SELECT LAST_INSERT_ID() AS id")
        int saveUser(User user);
        
        @Delete("DELETE FROM TB_USER WHERE id = #{id}")
        int removeUser(@Param("id") Integer id);
        
        @Update("UPDATE TB_USER SET name = #{name},sex = #{sex},age = #{age} WHERE id = #{id}")
        void modifyUser(User user);
        
        @Select("SELECT * FROM TB_USER WHERE id = #{id}")
        @Results({
            @Result(id=true,column="id",property="id"),
            @Result(column="name",property="name"),
            @Result(column="sex",property="sex"),
            @Result(column="age",property="age")
        })
        User selectUserById(@Param("id") Integer id);
        
        @Select("SELECT * FROM TB_USER ")
        List<User> selectAllUser();
    
    }

**四 配置文件**

1 db.properties

driver=com.mysql.jdbc.Driver
    url=jdbc:mysql://127.0.0.1:3306/mybatis
    username=root
    password=123456

2 log4j.xml

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">  
    <log4j:configuration  xmlns:log4j="http://jakarta.apache.org/log4j/">  
        <appender name="STDOUT"  class="org.apache.log4j.ConsoleAppender">  
            <layout class="org.apache.log4j.PatternLayout">  
                <param name="ConversionPattern" value="%5p [%t] %m%n"  />  
            </layout>  
        </appender>   
         <logger name="org.fkit.mapper">  
            <level value="DEBUG" />  
        </logger>
        <root>  
            <level value="ERROR" />  
            <appender-ref ref="STDOUT" />  
        </root>  
    </log4j:configuration>

3 mybatis-config.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>
         <properties resource="db.properties"/>
         
         <settings>
               <setting name="logImpl" value="LOG4J"/>
         </settings>
         <environments default="mysql">
         
        <environment id="mysql">
        
          <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>
      
      <mappers>
          <mapper class="org.fkit.mapper.UserMapper"/>
      </mappers>
    </configuration>

**五 测试**

1 InsertTest

package org.fkit.test;
    
    import org.apache.ibatis.session.SqlSession;
    import org.fkit.domain.User;
    import org.fkit.factory.FKSqlSessionFactory;
    import org.fkit.mapper.UserMapper;
    
    public class InsertTest {
    
        public static void main(String[] args) {
            // 定义SqlSession变量
            SqlSession sqlSession = null;
            try {
                // 创建SqlSession实例
                sqlSession = FKSqlSessionFactory.getSqlSession();
                
                // 创建UserMapper实例
                UserMapper um = sqlSession.getMapper(UserMapper.class);
                // 创建User对象并设置属性
                User user = new User();
                user.setName("test");
                user.setSex("男");
                user.setAge(18);
                // 插入数据
                um.saveUser(user);
                // 查看插入数据生成的主键
                System.out.println("插入数据生成的主键id为：" + user.getId());
                
                // 提交事务
                sqlSession.commit();
            } catch (Exception e) {
                // 回滚事务
                sqlSession.rollback();
                e.printStackTrace();
            }finally {
                // 关闭SqlSession
                if(sqlSession != null)
                    sqlSession.close();
            }
        }
    
    }

测试结果

DEBUG [main] ==>  Preparing: INSERT INTO TB_USER(name,sex,age)  VALUES(?,?,?)
    DEBUG [main] ==> Parameters: test(String), 男(String),  18(Integer)
    DEBUG [main] <==    Updates: 1
    插入数据生成的主键id为：3

2 SelectAllTest

package org.fkit.test;
    
    import java.util.List;
    import org.apache.ibatis.session.SqlSession;
    import org.fkit.domain.User;
    import org.fkit.factory.FKSqlSessionFactory;
    import org.fkit.mapper.UserMapper;
    public class SelectAllTest {
    
        public static void main(String[] args)  {
            // 定义SqlSession变量
            SqlSession sqlSession = null;
            try {
                // 创建SqlSession实例
                sqlSession = FKSqlSessionFactory.getSqlSession();
                // 创建UserMapper实例
                UserMapper um = sqlSession.getMapper(UserMapper.class);
                // 根据id查询User对象
                List<User> list = um.selectAllUser();
                // 查看查询到的User对象
                list.forEach(user->System.out.println(user));
                // 提交事务
                sqlSession.commit();
            } catch (Exception e) {
                // 回滚事务
                sqlSession.rollback();
                e.printStackTrace();
            }finally {
                // 关闭SqlSession
                if(sqlSession != null)
                    sqlSession.close();
            }
        }
    
    }

测试结果

DEBUG [main] ==>  Preparing: SELECT * FROM TB_USER
    DEBUG [main] ==> Parameters:
    DEBUG [main] <==      Total: 3
    User [id=1, name=cakin, sex=男, age=18]
    User [id=2, name=jack, sex=男, age=20]
    User [id=3, name=test, sex=男, age=18]

3 SelectTest

package org.fkit.test;
    
    import org.apache.ibatis.session.SqlSession;
    import org.fkit.domain.User;
    import org.fkit.factory.FKSqlSessionFactory;
    import org.fkit.mapper.UserMapper;
    public class SelectTest {
    
        public static void main(String[] args) {
            // 定义SqlSession变量
            SqlSession sqlSession = null;
            try {
                // 创建SqlSession实例
                sqlSession = FKSqlSessionFactory.getSqlSession();
                // 创建UserMapper实例
                UserMapper um = sqlSession.getMapper(UserMapper.class);
                // 根据id查询User对象
                User user = um.selectUserById(1);
                // 查看查询到的User对象
                System.out.println(user);
                // 提交事务
                sqlSession.commit();
            } catch (Exception e) {
                // 回滚事务
                sqlSession.rollback();
                e.printStackTrace();
            }finally {
                // 关闭SqlSession
                if(sqlSession != null)
                    sqlSession.close();
            }
        }
    
    }

测试结果

DEBUG [main] ==>  Preparing: SELECT * FROM TB_USER WHERE id = ?
    DEBUG [main] ==> Parameters: 1(Integer)
    DEBUG [main] <==      Total: 1
    User [id=1, name=cakin, sex=男, age=18]

4 UpdateTest

package org.fkit.test;
    
    import org.apache.ibatis.session.SqlSession;
    import org.fkit.domain.User;
    import org.fkit.factory.FKSqlSessionFactory;
    import org.fkit.mapper.UserMapper;
    public class UpdateTest {
    
        public static void main(String[] args)  {
            // 定义SqlSession变量
            SqlSession sqlSession = null;
            try {
                // 创建SqlSession实例
                sqlSession = FKSqlSessionFactory.getSqlSession();
                // 创建UserMapper实例
                UserMapper um = sqlSession.getMapper(UserMapper.class);
                // 查询id=5的User对象
                User user = um.selectUserById(2);
                // 修改查询到的User对象
                user.setName("update");
                user.setSex("女");
                user.setAge(19);
                // 修改User对象
                um.modifyUser(user);
                // 提交事务
                sqlSession.commit();
            } catch (Exception e) {
                // 回滚事务
                sqlSession.rollback();
                e.printStackTrace();
            }finally {
                // 关闭SqlSession
                if(sqlSession != null)
                    sqlSession.close();
            }
        }
    
    }

测试结果

DEBUG [main] ==>  Preparing: SELECT * FROM TB_USER WHERE id = ?
    DEBUG [main] ==> Parameters: 2(Integer)
    DEBUG [main] <==      Total: 1
    DEBUG [main] ==>  Preparing: UPDATE TB_USER SET name = ?,sex =  ?,age = ? WHERE id = ?
    DEBUG [main] ==> Parameters: update(String), 女(String),  19(Integer), 2(Integer)
    DEBUG [main] <==    Updates: 1

5 DeleteTest

package org.fkit.test;
    
    import org.apache.ibatis.session.SqlSession;
    import org.fkit.factory.FKSqlSessionFactory;
    import org.fkit.mapper.UserMapper;
    public class DeleteTest {
    
        public static void main(String[] args)  {
            // 定义SqlSession变量
            SqlSession sqlSession = null;
            try {
                // 创建SqlSession实例
                sqlSession = FKSqlSessionFactory.getSqlSession();
                // 创建UserMapper实例
                UserMapper um = sqlSession.getMapper(UserMapper.class);
                // 删除User对象
                um.removeUser(2);
                // 提交事务
                sqlSession.commit();
            } catch (Exception e) {
                // 回滚事务
                sqlSession.rollback();
                e.printStackTrace();
            }finally {
                // 关闭SqlSession
                if(sqlSession != null)
                    sqlSession.close();
            }
                    
        }
    
    }

测试结果

DEBUG [main] ==>  Preparing: DELETE FROM TB_USER WHERE id = ?
    DEBUG [main] ==> Parameters: 2(Integer)
    DEBUG [main] <==    Updates: 1