mybatis中使用XML配置文件方式实现CRUD模板流程

场景

Eclipse+Mybatis3.4+log4j1.2+mysql5.7

使用新手入门学习Mybatis时实例模板。

实现

Eclipse中新建项目

1.打开EClipse，File--new--java Project,名字叫做MybatisTemplate,点击Finish。

2.然后右击项目--Build Path--Config Build Path

3.选择Libraries下的Add External JARs

4.选择mybatis的jar包、log4j的jar包、连接mysql所需要的jar包

jar包下载：​​https://github.com/badaoliumang/jarPackageCollection​​

5.然后点击Apply--Apply and Close

6.新建包，目录如下

7.新建配置文件log4j.properties(log4j日志配置文件)、mybatis-config.xml(mybatis配置文件),目录如下

创建数据库

1.新建数据库ssmTemplate

2.新建表User，字段如下，注意id是自增主键。

代码实现

1.pojo包下新建User.java

package com.badao.ssm.ssmTemplate.pojo;

public class User {
 private int id;
 private String userName;
 private String remark;
 public int getId() {
  return id;
 }
 public void setId(int id) {
  this.id = id;
 }
 public String getUserName() {
  return userName;
 }
 public void setUserName(String userName) {
  this.userName = userName;
 }
 public String getRemark() {
  return remark;
 }
 public void setRemark(String remark) {
  this.remark = remark;
 }

}

2.mapper包新建UserMapper.java接口

package com.badao.ssm.ssmTemplate.mapper;

import java.util.List;

import com.badao.ssm.ssmTemplate.pojo.User;


public interface UserMapper {
 public int insertUser(User user);
 public int deleteUser(int id);
 public int updateUser(User user);
 public User getUser(int id);
 public List<User> findUsers(String userName);
}

3.mapper包下新建UserMapper.xml映射文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.badao.ssm.ssmTemplate.mapper.UserMapper">

 <insert id="insertUser" parameterType="user" useGeneratedKeys="true" keyProperty="id">
  insert into User(userName, remark) values(#{userName}, #{remark})
 </insert>

 <delete id="deleteUser" parameterType="int">
  delete from User where id= #{id}
 </delete>

 <update id="updateUser" parameterType="user">
  update User set userName = #{userName}, remark = #{remark} where id= #{id}
 </update>

 <select id="getUser" parameterType="int" resultType="user">
  select id,
  userName as userName, remark from User where id = #{id}
 </select>

 <select id="findUsers" parameterType="string" resultType="user">
  select id, userName as userName, remark from User
  where userName like concat('%', #{userName}, '%')
 </select>
</mapper>

其中namespace属性要与接口的全路径一样，即包名加接口名。

注意id为自增主键，所以针对于mybatis要配置:

seGeneratedKeys="true" keyProperty="id"

4.配置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>
  <typeAliases><!-- 别名 -->
      <typeAlias alias="user" type="com.badao.ssm.ssmTemplate.pojo.User"/>
  </typeAliases>
  <!-- 数据库环境 -->
  <environments default="development">
    <environment id="development">
      <transactionManager type="JDBC"/>
      <dataSource type="POOLED">
        <property name="driver" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/ssmTemplate"/>
        <property name="username" value="root"/>
        <property name="password" value=""/>
      </dataSource>
    </environment>
  </environments>
  <!-- 映射文件 -->
  <mappers>
    <mapper resource="com/badao/ssm/ssmTemplate/mapper/UserMapper.xml"/>
  </mappers>
</configuration>

注：

别名配置是为了以后在别的地方用的时候不用写太长的别名。

映射文件要与上面的mapper文件所在的位置相对应。

5.配置log4j.properties

log4j.rootLogger=DEBUG , stdout
log4j.logger.org.mybatis=DEBUG
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p %d %C: %m%n

6.配置SqlSessionFactoryUtils类

package com.badao.ssm.ssmTemplate.utils;

import java.io.IOException;

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 SqlSessionFactoryUtils {

 private final static Class<SqlSessionFactoryUtils> LOCK = SqlSessionFactoryUtils.class;

 private static SqlSessionFactory sqlSessionFactory = null;

 private SqlSessionFactoryUtils() {
 }

 public static SqlSessionFactory getSqlSessionFactory() {
  synchronized (LOCK) {
   if (sqlSessionFactory != null) {
    return sqlSessionFactory;
   }
   String resource = "mybatis-config.xml";
   InputStream inputStream;
   try {
    inputStream = Resources.getResourceAsStream(resource);
    sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
   } catch (IOException e) {
    e.printStackTrace();
    return null;
   }
   return sqlSessionFactory;
  }
 }

 public static SqlSession openSqlSession() {
  if (sqlSessionFactory == null) {
   getSqlSessionFactory();
  }
  return sqlSessionFactory.openSession(true);
 }
}

测试CRUD

1.新建MybatisMain.java 用于测试CRUD

package com.badao.ssm.ssmTemplate.main;
import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.apache.log4j.Logger;

import com.badao.ssm.ssmTemplate.mapper.UserMapper;
import com.badao.ssm.ssmTemplate.pojo.User;
import com.badao.ssm.ssmTemplate.utils.SqlSessionFactoryUtils;
public class MybatisMain {

 public static void main(String[] args) {
  testUserMapper();
  
  
 }
 private static void testUserMapper() {
  Logger log = Logger.getLogger(MybatisMain.class);
  SqlSession sqlSession = null;
  try {
   sqlSession = SqlSessionFactoryUtils.openSqlSession();
   UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
   //测试查询
   /*Role role = roleMapper.getRole(1l);
   log.info(role.getRoleName());*/
   //测试更新
   /*Role role3 = new Role();
   role3.setId(1l);
   role3.setRoleName("YSH");
   role3.setNote("测试更新");
   int updateResult = roleMapper.updateRole(role3);*/
   
   //测试插入
   /*testInsert();
   User user =new User();
   user.setUserName("霸道");
   user.setRemark("测试");
   int insertResult = userMapper.insertUser(user);
   if(insertResult == 0) {
    System.out.println("插入失败");
    log.info("插入失败");
   }else {
    System.out.println("插入成功");
    log.info("插入成功");
   }*/
   
   //测试查询
   /*User user2 = userMapper.getUser(1);
   log.info("查询到的用户名为："+user2.getUserName());*/
   
   //测试更新
   /*User user3 = new User();
   user3.setId(1);
   user3.setUserName("霸道------");
   user3.setRemark("更新成功了");
   int updateResult = userMapper.updateUser(user3);
   if(updateResult == 0) {
    System.out.println("更新失败");
    log.info("更新失败");
   }else {
    System.out.println("更新成功");
    log.info("更新成功");
   }*/
   
   //测试删除
   /*int deleteResule = userMapper.deleteUser(1);
   if(deleteResule == 0) {
    System.out.println("删除失败");
    log.info("删除失败");
   }else {
    System.out.println("删除成功");
    log.info("删除成功");
   }*/
   
   //测试模糊查询
   /*List<User> userList = userMapper.findUsers("霸");
   for (User user : userList) {
    System.out.println(user.getUserName());
   }*/
  } finally {
   if (sqlSession != null) {
    sqlSession.close();
   }
  }
 }
 private static void testInsert() {
  // TODO Auto-generated method stub
  
 }
 
}

2.测试插入

2.测试查询

3.测试更新

4.测试删除

5.测试模糊查询

项目下载

github:

​​https://github.com/badaoliumang/SSMCodeCollection/tree/master/MybatisTemplate​​

项目总目录