MyBtais整合Spring Boot整合，TypeHandler对枚举类（enum）处理

概要

问题描述

我想用枚举类来表示用户当前状态，枚举类由 code 和 msg 组成，但我只想把 code 保存到数据库，查询处理，能知道用户当前状态，这应该怎么做呢？在 Spring 整合MyBatis 的时候，我们有一个MyBatis的配置文件，我们可以用下面的标签样式指定


那 Spring Boot 整合 MyBatis 呢？
解决方案
MyBatis为我们提供了解决方案：你可以集成 baseTypeHandler，或者实现 TypeHandler。我们需要在应用配置文件中指定handler的路径
  type-handlers-package: com.xxx.handlers

另外，我们需要在Handler上添加注解，指明枚举类（enum）。
枚举类
package com.fengwenyi.learn.java.mybatisenum;


public enum Status {

    LOGIN(100, "在线"),
    LOGOUT(200, "不在线")
    ;

    private Integer code;
    private String msg;

    Status(Integer code, String msg) {
 this.code = code;
 this.msg = msg;
    }

    
    public static Status getStatusByCode(Integer code) {
 switch (code) {
     case 100:
  return LOGIN;
     case 200:
  return LOGOUT;
     default:
  return LOGOUT;
 }
    }

    // getter
}

TypeHandler
package com.fengwenyi.learn.java.mybatisenum.handlers;

import com.fengwenyi.learn.java.mybatisenum.Status;
import org.apache.ibatis.type.JdbcType;
import org.apache.ibatis.type.MappedTypes;
import org.apache.ibatis.type.TypeHandler;

import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;



@MappedTypes({Status.class})
public class UserStatusTypeHandler implements TypeHandler {

    @Override
    public void setParameter(PreparedStatement preparedStatement, int i, Status status, JdbcType jdbcType) throws SQLException {
 preparedStatement.setInt(i, status.getCode());
    }

    @Override
    public Status getResult(ResultSet resultSet, String s) throws SQLException {
 Integer code = resultSet.getInt(s);
 return Status.getStatusByCode(code);
    }

    @Override
    public Status getResult(ResultSet resultSet, int i) throws SQLException {
 Integer code = resultSet.getInt(i);
 return Status.getStatusByCode(code);
    }

    @Override
    public Status getResult(CallableStatement callableStatement, int i) throws SQLException {
 Integer code = callableStatement.getInt(i);
 return Status.getStatusByCode(code);
    }
}

application.yml
spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/learn
    username: root
    password: xfsy2018
mybatis:
  type-aliases-package: com.fengwenyi.learn.java.mybatisenum.model
  mapper-locations: classpath:mapper/*.xml
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
  type-handlers-package: com.fengwenyi.learn.java.mybatisenum.handlers

测试
@Autowired
private IUserService userService;

@Test
public void contextLoads() {

    // find();
    insert();
}

private void insert() {
    UserModel model = new UserModel();
    model.setStatus(Status.LOGIN);
    boolean rs = userService.save(model);
    System.out.println(rs);
}

private void find() {
    List modelList = userService.findAll();
    for (UserModel model : modelList) {
 System.out.println(model.toString());
    }
}

数据


测试代码
https://github.com/fengwenyi/JavaLearnProject/tree/master/mybatis-enum

MyBtais整合Spring Boot整合，TypeHandler对枚举类（enum）处理

SpringBoot相关栏目本月热门文章