代码规范

VO包

当我们给前台传数据的时候,可能不想要将所有的数据项都传给前台,这时候需要使用VO映射类来封装我们的 数据

domain/vo/实体类名字

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package com.nuyoah.domain.vo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

/**
* 当我们返回给前端数据的时候,并不是想要将数据库中的所有数据项都展示出来
* 这时候我们可以使用vo封装我们想要给前台展示的数据
*/

@Data
@NoArgsConstructor
@AllArgsConstructor
public class HotArticleVo {
private Long id;
private String title;
private Long viewCount;
}

实体对象转换成VO对象

service/impl/service对象

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package com.nuyoah.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.fasterxml.jackson.databind.util.BeanUtil;
import com.nuyoah.domain.ResponseResult;
import com.nuyoah.domain.entity.Article;
import com.nuyoah.domain.vo.HotArticleVo;
import com.nuyoah.mapper.ArticleMapper;
import com.nuyoah.service.ArticleService;

import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;

/**
* 文章表(Article)表服务实现类
*
* @author makejava
* @since 2024-03-07 21:07:55
*/
@Service
public class ArticleServiceImpl extends ServiceImpl<ArticleMapper, Article> implements ArticleService {

@Override
public ResponseResult hostArticleList() {
// 构建查询对象
LambdaQueryWrapper<Article> lambdaQueryWrapper = new LambdaQueryWrapper<>();
// 构建查询参数
// 正式文章
lambdaQueryWrapper.eq(Article::getStatus, 0);
// 按照浏览量排序
lambdaQueryWrapper.orderByAsc(Article::getViewCount);
// 最多展示10条
Page<Article> page = new Page<>(1, 10);
page(page, lambdaQueryWrapper);

List<Article> articles = page.getRecords();
// 将查到的数据进行封装,分装成Vo数据类型
// bean拷贝
List<HotArticleVo> hotArticleVos = new ArrayList<>();
for (Article article : articles) {
HotArticleVo vo = new HotArticleVo();
BeanUtils.copyProperties(article, vo);
hotArticleVos.add(vo);
}
return ResponseResult.okResult(hotArticleVos);
}

}


封装工具类将Bean转换成VO的代码封装一下

utils

返回前台状态和对象

我们可以封装一个类来给前台返回对象,例如状态信息,文字信息,数据信息

enums/AppHttpCodeEnum.java前台状态码

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package com.nuyoah.enums;

public enum AppHttpCodeEnum {
// 成功
SUCCESS(200,"操作成功"),
// 登录
NEED_LOGIN(401,"需要登录后操作"),
NO_OPERATOR_AUTH(403,"无权限操作"),
SYSTEM_ERROR(500,"出现错误"),
USERNAME_EXIST(501,"用户名已存在"),
PHONENUMBER_EXIST(502,"手机号已存在"), EMAIL_EXIST(503, "邮箱已存在"),
REQUIRE_USERNAME(504, "必需填写用户名"),
LOGIN_ERROR(505,"用户名或密码错误");
int code;
String msg;

AppHttpCodeEnum(int code, String errorMessage){
this.code = code;
this.msg = errorMessage;
}

public int getCode() {
return code;
}

public String getMsg() {
return msg;
}
}

domain/ResponseResult返回对象

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package com.nuyoah.domain;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.nuyoah.enums.AppHttpCodeEnum;
import java.io.Serializable;

/**
* @author 35238
* @date 2023/7/19 0019 12:49
*/
//统一响应格式。实体类,或者这个类严格来说叫响应体
@JsonInclude(JsonInclude.Include.NON_NULL)
public class ResponseResult<T> implements Serializable {
private Integer code;
private String msg;
private T data;

public ResponseResult() {
this.code = AppHttpCodeEnum.SUCCESS.getCode();
this.msg = AppHttpCodeEnum.SUCCESS.getMsg();
}

public ResponseResult(Integer code, T data) {
this.code = code;
this.data = data;
}

public ResponseResult(Integer code, String msg, T data) {
this.code = code;
this.msg = msg;
this.data = data;
}

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

public static ResponseResult errorResult(int code, String msg) {
ResponseResult result = new ResponseResult();
return result.error(code, msg);
}
public static ResponseResult okResult() {
ResponseResult result = new ResponseResult();
return result;
}
public static ResponseResult okResult(int code, String msg) {
ResponseResult result = new ResponseResult();
return result.ok(code, null, msg);
}

public static ResponseResult okResult(Object data) {
ResponseResult result = setAppHttpCodeEnum(AppHttpCodeEnum.SUCCESS, AppHttpCodeEnum.SUCCESS.getMsg());
if(data!=null) {
result.setData(data);
}
return result;
}

public static ResponseResult errorResult(AppHttpCodeEnum enums){
return setAppHttpCodeEnum(enums,enums.getMsg());
}

public static ResponseResult errorResult(AppHttpCodeEnum enums, String msg){
return setAppHttpCodeEnum(enums,msg);
}

public static ResponseResult setAppHttpCodeEnum(AppHttpCodeEnum enums){
return okResult(enums.getCode(),enums.getMsg());
}

private static ResponseResult setAppHttpCodeEnum(AppHttpCodeEnum enums, String msg){
return okResult(enums.getCode(),msg);
}

public ResponseResult<?> error(Integer code, String msg) {
this.code = code;
this.msg = msg;
return this;
}

public ResponseResult<?> ok(Integer code, T data) {
this.code = code;
this.data = data;
return this;
}

public ResponseResult<?> ok(Integer code, T data, String msg) {
this.code = code;
this.data = data;
this.msg = msg;
return this;
}

public ResponseResult<?> ok(T data) {
this.data = data;
return this;
}

public Integer getCode() {
return code;
}

public void setCode(Integer code) {
this.code = code;
}

public String getMsg() {
return msg;
}

public void setMsg(String msg) {
this.msg = msg;
}

public T getData() {
return data;
}

public void setData(T data) {
this.data = data;
}

}

返回对象

service

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package com.nuyoah.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.fasterxml.jackson.databind.util.BeanUtil;
import com.nuyoah.domain.ResponseResult;
import com.nuyoah.domain.entity.Article;
import com.nuyoah.domain.vo.HotArticleVo;
import com.nuyoah.mapper.ArticleMapper;
import com.nuyoah.service.ArticleService;

import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;

/**
* 文章表(Article)表服务实现类
*
* @author makejava
* @since 2024-03-07 21:07:55
*/
@Service
public class ArticleServiceImpl extends ServiceImpl<ArticleMapper, Article> implements ArticleService {

@Override
public ResponseResult hostArticleList() {
// 构建查询对象
LambdaQueryWrapper<Article> lambdaQueryWrapper = new LambdaQueryWrapper<>();
// 构建查询参数
// 正式文章
lambdaQueryWrapper.eq(Article::getStatus, 0);
// 按照浏览量排序
lambdaQueryWrapper.orderByAsc(Article::getViewCount);
// 最多展示10条
Page<Article> page = new Page<>(1, 10);
page(page, lambdaQueryWrapper);

List<Article> articles = page.getRecords();
// 将查到的数据进行封装,分装成Vo数据类型
// bean拷贝
List<HotArticleVo> hotArticleVos = new ArrayList<>();
for (Article article : articles) {
HotArticleVo vo = new HotArticleVo();
BeanUtils.copyProperties(article, vo);
hotArticleVos.add(vo);
}
// 封装返回信息
return ResponseResult.okResult(hotArticleVos);
}

}

常量类

当我们数据库中有数字表示状态信息的时候,在JAVA里面需要封装一个常量类,这样在修改状态字符的时候,只需要修改常量类中的数字即可

constants/SystemConstants

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package com.nuyoah.constants;

public class SystemConstants {
/**
* 文章是草稿
*/
public static final int ARTICLE_STATUS_DRAFT = 1;

/**
* 文章是正常分布状态
*/
public static final int ARTICLE_STATUS_NORMAL = 0;
}

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@Service
public class ArticleServiceImpl extends ServiceImpl<ArticleMapper, Article> implements ArticleService {

@Override
public ResponseResult hostArticleList() {

LambdaQueryWrapper<Article> lambdaQueryWrapper = new LambdaQueryWrapper<>();
// 将status数字转换为常量
lambdaQueryWrapper.eq(Article::getStatus, SystemConstans.ARTICLE_STATUS_DRAFT);

}

}