mybatis中resulthandler的用法
作者：杭川奇迹
这篇文章主要介绍了mybatis中resulthandler的用法，具有很好的参考价值，希望对大家有所帮助。如有错误或未考虑完全的地方，望不吝赐教
resulthandler的用法
ResultHandler，顾名思义，对返回的结果进行处理，最终得到自己想要的数据格式或类型。也就是说，可以自定义返回类型。下面通过一个例子讲解它的使用方法：
创建实体类
package com.ccb.demossm.entity;
import com.ccb.demossm.annotation.MyAnnotation;
import org.springframework.stereotype.Component;
@Component
public class Users {
//用户ID
private String userId;
//用户名
private String userName;
//用户密码
private String userPwd;
//用户性别
public String sex;
//备注
protected String mark;
public String getMark() {
return mark;
}
public void setMark(String mark) {
this.mark = mark;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getUserId() {
return userId;
}
public void setUserId(String userId) {
this.userId = userId;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getUserPwd() {
return userPwd;
}
public void setUserPwd(String userPwd) {
this.userPwd = userPwd;
}
public Users() {
}
public Users(String userId) {
this.userId = userId;
}
}
sql，返回值类型要写
<select id="getUserResult" resultType="com.ccb.demossm.entity.Users"> select u.userId,u.userName, u.userPwd from users u </select>
Mapper，返回值必须是void
void getUserResult(ResultHandler<Users> resultHandler);package com.ccb.demossm.mapper;
import com.ccb.demossm.entity.Users;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.session.ResultHandler;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.stereotype.Repository;
import java.util.List;
import java.util.Map;
@Repository
@SpringBootApplication
public interface UsersMapper {
void getUserResult(ResultHandler<Users> resultHandler);
}
Test
package com.ccb.demossm;
import com.ccb.demossm.entity.Users;
import com.ccb.demossm.mapper.UsersMapper;
import org.apache.ibatis.session.ResultContext;
import org.apache.ibatis.session.ResultHandler;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
@SpringBootTest
@RunWith(SpringRunner.class)
public class TestResultHandle {
@Autowired
private UsersMapper usersMapper;
@Test
public void test() {
usersMapper.getUserResult(new ResultHandler<Users>() {
@Override
public void handleResult(ResultContext<? extends Users> resultContext) {
Users resultObject = resultContext.getResultObject();
String userId = resultObject.getUserId();
//写数据处理业务
System.out.println(userId);
}
});
}
}
ResultHandler(传入map返回map)
测试代码
package com.xwhbshweb.service;
import java.util.HashMap;
import java.util.Map;
import org.apache.ibatis.session.ResultContext;
import org.apache.ibatis.session.ResultHandler;
public interface OrdersService {
/**
* 返回某日订单成交数及当日成交总金额 day 的格式为 2018/01/30
*
* 若 day 为 null 则返回总成交订单及总成交金额
*
* @param id
* 商户号
* @param day
* @return
*/
public Map<String, String> getOrderCountTotal(String id, String day);
/**
* 处理 select 结果
*
* @author Administrator
*
*/
class OrdersResultHandler implements ResultHandler {
private final Map<String, String> mappedResults = new HashMap<String, String>();
@Override
public void handleResult(ResultContext resultContext) {
Map map = (Map) resultContext.getResultObject();
if (map.get("count") instanceof Long) {
System.out.println("count Long ");
if (null == String.valueOf((Long) map.get("count"))
|| String.valueOf((Long) map.get("count")).equals("")) {
mappedResults.put("count", "0");
} else {
mappedResults.put("count", String.valueOf((Long) map.get("count")));
}
}
if (map.get("total") instanceof Double) {
System.out.println("total Long ");
String total = String.valueOf((Double) map.get("total")).split("\\.")[0];
if (total.equals("0")) {
mappedResults.put("total", "0");
}else {
float yuan = Float.valueOf(total) / 1000;
mappedResults.put("total", String.valueOf(yuan));
}
}
}
public Map getMappedResults() {
return mappedResults;
}
}
}实现
package com.xwhbshweb.service.imp;
import java.util.HashMap;
import java.util.Map;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.springframework.stereotype.Service;
import com.xwhbshweb.config.MybatisSqlSessionFactory;
import com.xwhbshweb.service.OrdersService;
@Service
public class OrdersServiceI implements OrdersService {
private SqlSessionFactory sqlSessionFactory = MybatisSqlSessionFactory.getOne();
@Override
public Map<String, String> getOrderCountTotal(String id,String day) {
SqlSession session = sqlSessionFactory.openSession(true);
Map<String, String> params = new HashMap<String, String>();
params.put("id", id);
if (null == day) {
params.put("day", "%");
}else {
params.put("day", day+"%");
}
OrdersService.OrdersResultHandler handler = new OrdersService.OrdersResultHandler();
session.select("com.xwhbank.cn.config.mybatis.namespace.ordersMapper.selectDayOrderCountTotal", params, handler);
session.close();
Map<String,String> map =handler.getMappedResults();
return map;
}
}xml
<?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.xwhbank.cn.config.mybatis.namespace.ordersMapper">
<select id="selectOne" resultType="orders">
select * from orders where the_super_id = #{id};
</select>
<select id="selectDayOrderCountTotal" parameterType="java.util.Map" resultType="java.util.HashMap">
select count(*) as count,SUM(money_to_tenant) as total from orders where the_super_id = #{id} and order_time like #{day} and state='2';
</select>
<insert id="insertOne" parameterType="orders">
insert into orders (id,tenant_order_no,the_super_id,state,money_amount,cut,money_to_tenant,money_to_xwh,pay_way,good_info,asy_notify_url,sy_return_url,sign_,order_time,sharding_id) values ("next value for MYCATSEQ_order",#{tenant_order_no},#{the_super_id},#{state},#{money_amount},#{cut},#{money_to_tenant},#{money_to_xwh},#{pay_way},#{good_info},#{asy_notify_url},#{sy_return_url},#{sign_},#{order_time},#{sharding_id});
</insert>
</mapper>注意传入 map参数 及 传出map参数 的颜色对应
map传入值时 若是不同类型 将 map的值改为Object就好了
以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。