第七色在线视频,2021少妇久久久久久久久久,亚洲欧洲精品成人久久av18,亚洲国产精品特色大片观看完整版,孙宇晨将参加特朗普的晚宴

整合mybatis相關(guān)配置

mybatis:

????type-aliases-package: #實(shí)體類掃描路徑

????mapper-locations: classpath:mappers/*.xml #所有mapper映射文件所在目錄

mapper:

????mappers:#所有mapper需要實(shí)現(xiàn)的接口

????not-empty:false #進(jìn)行數(shù)據(jù)庫操作時(shí)，是否對(duì)屬性追加不為空字符串的判斷

? ? identity:?MYSQL

#分頁插件助手的配置

pagehelper:

????helper-dialect:mysql

????support-methods-arguments:true

整合mybatis依賴導(dǎo)入

配置HicariCP數(shù)據(jù)源：

引入HicariCP數(shù)據(jù)源依賴

import?java.io.Serializable;
import?java.util.HashMap;
import?java.util.Map;

/*
????使用@RestController或@ResponseBody時(shí)，可直接返回該對(duì)象，
????Spring?Boot默認(rèn)使用Jackson會(huì)自動(dòng)將該對(duì)象轉(zhuǎn)換為json字符串
????如{"code":?0,"msg":?"","data":?[{},?{}]}
?*/
public?class?JsonResult?extends?HashMap<String,?Object>?implements?Serializable?{
????public?static?final?long?serialVersionUID?=?1L;

????public?static?final?int?SUCCESS?=?0;
????public?static?final?int?FAIL?=?1;
????public?static?final?int?ERROR?=?2;
????public?static?final?int?LOGOUT?=?1001;

????public?JsonResult(int?code,?String?msg,?Object?data)?{
????????super(3);??//繼承自Map，設(shè)置初始容量
????????this.put("code",?code);?//狀態(tài)碼，layui中code=0表示成功
????????this.put("msg",?msg);???//提示消息
????????this.put("data",?data);?//數(shù)據(jù)體
????}

????//一般返回code、msg和data這三個(gè)即可，但layui加載table時(shí)還要求count值
????//添加額外的返回值
????public?JsonResult?put(String?key,?Object?value)?{
????????super.put(key,?value);
????????return?this;
????}

????//快速返回請(qǐng)求成功
????public?static?JsonResult?success(Object?data)?{
????????return?new?JsonResult(SUCCESS,?"ok",?data);
????}

????//快速返回請(qǐng)求失敗
????public?static?JsonResult?fail(String?msg)?{
????????return?new?JsonResult(FAIL,?msg,?null);
????}

????public?static?JsonResult?error(String?msg,?Object?data)?{
????????return?new?JsonResult(ERROR,?msg,?data);
????}

????public?static?JsonResult?logout()?{
????????return?new?JsonResult(LOGOUT,?"未登錄",?null);
????}

????//快速生成一個(gè)Map鍵值對(duì)
????public?static?Map<String,?Object>?fastMap(String?key,?Object?value)?{
????????Map<String,?Object>?data?=?new?HashMap<>(1);
????????data.put(key,?value);
????????return?data;
????}
}

4字開頭的錯(cuò)誤是前段的錯(cuò)誤

5字開頭的是后端的錯(cuò)誤

spring tool

寫映射文件，有利于dba做sql審核 ，優(yōu)化

異步任務(wù)

定時(shí)任務(wù)的使用場(chǎng)景：

如更新庫存

建立一個(gè)配置類

@Configuration

@EnableScheduling

@Slf4j

public class MyTask{

????????//添加一個(gè)任務(wù)，并且注明任務(wù)的運(yùn)行表達(dá)式

????????@Scheduled(cron = "*/5 * * * * ?")

????`????public void publishMsg(){

????????????????log.warn("開始執(zhí)行任務(wù)：");

????????}

}

分布式的定時(shí)任務(wù)使用其它框架?

檢驗(yàn)參數(shù)

javax.validator

bo:業(yè)務(wù)對(duì)象

用于接收從前端傳入的數(shù)據(jù)

控制接收后再將它賦值給實(shí)體類對(duì)象

BeanUtils.copyProperties(sourceObj,targetObj)

通用響應(yīng)對(duì)象

public class JSONResult{

????private Integer status;

????private String msg;

????private Object data;

????private? String ok;

}

用于接受參數(shù)的注解

@RequestParam:et 用一獲得url中的參數(shù)

@PathVariable