【JavaWeb】项目后端部分统一解决方案

项目后端部分统一解决方案

文章目录

项目后端部分统一解决方案
一、异步响应规范格式类
二、MD5加密工具类
三、JwtHelper工具类
四、CrosFilter过滤器

一、异步响应规范格式类

Result类

package com.pro.common;/*** 全局统一返回结果类**/
public class Result<T> {// 返回码private Integer code;// 返回消息private String message;// 返回数据private T data;public Result(){}// 返回数据protected static <T> Result<T> build(T data) {Result<T> result = new Result<T>();if (data != null)result.setData(data);return result;}public static <T> Result<T> build(T body, Integer code, String message) {Result<T> result = build(body);result.setCode(code);result.setMessage(message);return result;}public static <T> Result<T> build(T body, ResultCodeEnum resultCodeEnum) {Result<T> result = build(body);result.setCode(resultCodeEnum.getCode());result.setMessage(resultCodeEnum.getMessage());return result;}/*** 操作成功* @param data  baseCategory1List* @param <T>* @return*/public static<T> Result<T> ok(T data){Result<T> result = build(data);return build(data, ResultCodeEnum.SUCCESS);}public Result<T> message(String msg){this.setMessage(msg);return this;}public Result<T> code(Integer code){this.setCode(code);return this;}public Integer getCode() {return code;}public void setCode(Integer code) {this.code = code;}public String getMessage() {return message;}public void setMessage(String message) {this.message = message;}public T getData() {return data;}public void setData(T data) {this.data = data;}
}

ResultCodeEnum 枚举类

package com.pro.common;
/*** 统一返回结果状态信息类**/
public enum ResultCodeEnum {SUCCESS(200,"success"),USERNAME_ERROR(501,"usernameError"),PASSWORD_ERROR(503,"passwordError"),NOTLOGIN(504,"notLogin"),USERNAME_USED(505,"userNameUsed");private Integer code;private String message;private ResultCodeEnum(Integer code, String message) {this.code = code;this.message = message;}public Integer getCode() {return code;}public String getMessage() {return message;}
}

二、MD5加密工具类

package com.pro.util;import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;public final class MD5Util {public static String encrypt(String strSrc) {try {char hexChars[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8','9', 'a', 'b', 'c', 'd', 'e', 'f' };byte[] bytes = strSrc.getBytes();MessageDigest md = MessageDigest.getInstance("MD5");md.update(bytes);bytes = md.digest();int j = bytes.length;char[] chars = new char[j * 2];int k = 0;for (int i = 0; i < bytes.length; i++) {byte b = bytes[i];chars[k++] = hexChars[b >>> 4 & 0xf];chars[k++] = hexChars[b & 0xf];}return new String(chars);} catch (NoSuchAlgorithmException e) {e.printStackTrace();throw new RuntimeException("MD5加密出错！！+" + e);}}
}

三、JwtHelper工具类

package com.pro.util;import com.alibaba.druid.util.StringUtils;
import io.jsonwebtoken.*;import java.util.Date;public class JwtHelper {private static long tokenExpiration = 24*60*60*1000;private static String tokenSignKey = "123456";//生成token字符串public static String createToken(Long userId) {String token = Jwts.builder().setSubject("YYGH-USER").setExpiration(new Date(System.currentTimeMillis() + tokenExpiration)).claim("userId", userId).signWith(SignatureAlgorithm.HS512, tokenSignKey).compressWith(CompressionCodecs.GZIP).compact();return token;}//从token字符串获取useridpublic static Long getUserId(String token) {if(StringUtils.isEmpty(token)) return null;Jws<Claims> claimsJws = Jwts.parser().setSigningKey(tokenSignKey).parseClaimsJws(token);Claims claims = claimsJws.getBody();Integer userId = (Integer)claims.get("userId");return userId.longValue();}//判断token是否有效public static boolean isExpiration(String token){try {boolean isExpire = Jwts.parser().setSigningKey(tokenSignKey).parseClaimsJws(token).getBody().getExpiration().before(new Date());//没有过期，有效，返回falsereturn isExpire;}catch(Exception e) {//过期出现异常，返回truereturn true;}}
}

步骤：

前端登陆时发送登陆请求，后端校验，成功则将用户id加密到token中，返回给前端
前端收到 token 存到 localStorage 或 sessionStorage 中
后续发送请求时都将 token 放到请求头中，带给后端

且前端在路由跳转前都需校验是否存在 token 才进行页面跳转（使用路由前置守卫）

四、CrosFilter过滤器

package com.pro.filters;import jakarta.servlet.*;
import jakarta.servlet.annotation.WebFilter;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;import java.io.IOException;@WebFilter("/*")
public class CrosFilter implements Filter {@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {HttpServletResponse response = (HttpServletResponse) servletResponse;HttpServletRequest request =(HttpServletRequest) servletRequest;response.setHeader("Access-Control-Allow-Origin", "*");response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE, HEAD");response.setHeader("Access-Control-Max-Age", "3600");response.setHeader("Access-Control-Allow-Headers", "access-control-allow-origin, authority, content-type, version-info, X-Requested-With");// 非预检请求,放行即可,预检请求,则到此结束,不需要放行if(!request.getMethod().equalsIgnoreCase("OPTIONS")){filterChain.doFilter(servletRequest, servletResponse);}}
}