blog/毕业论文/毕业论文-3.md

---
title: 毕业设计(3)
tags: 
    - java
    - ssm
    - react
    - ant design
    - typescript
categories: 毕业设计
date: 2022-12-10 12:38:32
summary: 基本工具类创建

---

## 六、创建Resp返回类

实体类分别包含了四个字段，code、data、errot、message

Resp.class

```java
package org.gjs.utils;


public class Resp<T> {
    int code;
    T data;
    String error;
    String message;

    public int getCode() {
        return code;
    }

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

    public T getData() {
        return data;
    }

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

    public String getError() {
        return error;
    }

    public void setError(String error) {
        this.error = error;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public Resp() {
    }

    public Resp(int code, T data, Exception error, String message) {
        this.code = code;
        this.data = data;
        if (error == null){
            this.error = "";
        }else {
            this.error = error.getMessage();
        }

        this.message = message;
    }

    public static <K> Resp<K> Ok(){
        return new Resp<K>(200,null,null,"");
    }
    public static <K>  Resp<K> Ok(K data){
        return new Resp<K>(200,data,null,"");
    }
    public static <K> Resp<K> Ok(K data,String message){
        return new Resp<K>(200,data,null,message);
    }


    public static <K> Resp<Boolean> Err(int code, Exception e){
        return new Resp<Boolean>(code,false,e,"");
    }

    public static <K> Resp<K> Err(int code, Exception e,K data){
        return new Resp<K>(code,data,e,"");
    }

    public static <K> Resp<K> Err(int code, Exception e,K data,String message){
        return new Resp<K>(code,data,e,message);
    }

    public static <K> Resp<Boolean> Err(int code,Exception e,String message){
        return new Resp<Boolean>(code,false,e,message);
    }
}
```

## 七、全局错误处理

通过**RestControllerAdvice**注解和**RestControllerAdvice**注解进行全局异常处理

ExceptionController.java

```java
package org.gjs.exception;


import org.apache.log4j.Logger;
import org.gjs.utils.Resp;
import org.jetbrains.annotations.NotNull;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import javax.servlet.http.HttpServletResponse;

@RestControllerAdvice
@Component
public class ExceptionController {


    private final Logger logger = Logger.getLogger(this.getClass());


    @ExceptionHandler({RuntimeException.class})
    public Object runtime(HttpServletResponse response,RuntimeException e){
        response.setStatus(503);
        e.printStackTrace();
        return Resp.Err(503,e,"服务端异常错误！");
    }

    @ExceptionHandler({NullPointerException.class})
    @ResponseBody
    @ResponseStatus(code = HttpStatus.SERVICE_UNAVAILABLE)
    public Object nullExc(HttpServletResponse response,Exception e){
        e.printStackTrace();
        return Resp.Err(503,e);
    }

    @ExceptionHandler({Exception.class})
    @ResponseBody
    @ResponseStatus(code = HttpStatus.SERVICE_UNAVAILABLE)
    public Object my(HttpServletResponse response, @NotNull Exception e){
        e.printStackTrace();
        return Resp.Err(503,e);
    }
}
```

## 八、Jwt工具类编写

首先在maven中导入jwt得依赖

```xml
<!-- https://mvnrepository.com/artifact/com.auth0/java-jwt -->
    <dependency>
      <groupId>com.auth0</groupId>
      <artifactId>java-jwt</artifactId>
      <version>4.2.1</version>
    </dependency>
```

工具类编写

Jwt.java

```java
package org.gjs.utils;


import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.interfaces.DecodedJWT;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.Calendar;
import java.util.Date;

public class Jwt {

    private static final String SECRET = "XX#$%()(#*!()!KL<><MQLMNQNQJQK sdfkjsdrow32234545fdf>?N<:{LWPW";

    private static final String EXP = "exp";

    private static final String PAYLOAD = "payload";

    private static final String ISSUE = "gjs";

    private static final Integer MAX_AGE =  60 * 60 * 24 * 30;

    //加密，传入一个对象和有效期
    public static <T> String sign(T object) {
        try {

            ObjectMapper mapper = new ObjectMapper();
            String jsonString = mapper.writeValueAsString(object);
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(new Date());
            calendar.add(Calendar.MONTH,1);
            return JWT.create()
                    .withIssuer(ISSUE)
                    .withClaim(PAYLOAD,jsonString)
                    .withExpiresAt(calendar.getTime())
                    .sign(Algorithm.HMAC256(SECRET));
        } catch(Exception e) {
            return null;
        }
    }

    //解密，传入一个加密后的token字符串和解密后的类型
    public static<T> T verify(String jwt, Class<T> classT) {
        try {
            JWTVerifier verifier = JWT.require(Algorithm.HMAC256(SECRET)).withIssuer(ISSUE).build();
            DecodedJWT v = verifier.verify(jwt);
            Date expiresAt = v.getExpiresAt();
            // 检查是否过期
            if (new Date().after(expiresAt) ){
                return null;
            }
            String s = v.getClaim(PAYLOAD).asString();
            ObjectMapper objectMapper = new ObjectMapper();
            return objectMapper.readValue(s, classT);
        } catch (JsonProcessingException e) {
            return null;
        }

    }
}
```

## 九、日志中间件实现

使用aop进行拦截日志记录

LogAop.java

```java
package org.gjs.aop;

import org.apache.log4j.Logger;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.Signature;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


@Aspect
@Component
public class LogAop {

    public LogAop() {
    }

    private final Logger logger = Logger.getLogger(this.getClass());

    @Before("execution(* org.gjs.controller.*.*(..))")
    public void before(JoinPoint point){

        Signature signature = point.getSignature();
        HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
        logger.info(request.getSession().getId()+" ----------------------------------------------------");
        logger.info(request.getSession().getId() +" - name: "+signature.getName());
        logger.info(request.getSession().getId()+" - ip: "+request.getRemoteAddr());
        logger.info(request.getSession().getId()+" - method: "+request.getMethod());
        logger.info(request.getSession().getId()+" - query: "+request.getQueryString());
        Object[] args = point.getArgs();
        for (Object a : args
        ) {
            if (a != null){
                logger.info(request.getSession().getId()+" - args: "+a.toString());
            }

        }
    }
    @AfterReturning(value = "execution(* org.gjs.controller.*.*(..))",returning = "methodResult")
    public void afterReturning(JoinPoint joinPoint, Object methodResult){
        HttpServletResponse res = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getResponse();
        HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
        logger.info(request.getSession().getId()+ " - status: "+res.getStatus());
        logger.info(request.getSession().getId()+ " - return: "+methodResult);
        logger.info(request.getSession().getId()+" ----------------------------------------------------");
    }
}
```

#