统一异常处理

代码托管地址:https://gitee.com/ZomiCC/code/tree/master/exception

非统一异常处理

A代码:try...catch...
B代码:try...catch...
C代码:try...catch...
D代码:try...catch...

统一异常处理

此文应用到了[统一校验]部分功能,没有看多可先参考上文:统一校验

统一处理,我们很容易会想到spring中的AOP。没错,本篇文章核心就是使用spring为我们提供的两个注解@RestControllerAdvice + @ExceptionHandler 来实现异常的统一处理。
我们的任务主要分以下几步:

  1. 自定义统一异常类BizException,规范异常类型,便于ExceptionHandler使用
  2. 对controller切面,实现对BindingResult(即调用者请求参数)的统一异常/校验处理,我们称这一步为前置异常捕获
  3. 对service切面,捕获所有的service异常,统一封装为BizException,再返回给controller,方便RestControllerAdvice+ExceptionHandler处理异常类型。我们称这一步为业务异常捕获
  4. 全局异常处理器中,也就是RestControllerAdvice+ExceptionHandler的处理方法中,封装响应结果返回给调用者。

关键代码

依赖包
       <!-- valid校验 -->
        <dependency>
            <groupId>javax.validation</groupId>
            <artifactId>validation-api</artifactId>
            <version>2.0.1.Final</version>
        </dependency>
        <!-- 想要BindResult生效,这个依赖一定要有 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>
        <!-- aop -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
统一异常定义
package com.example.exception.exception;

public class BizException extends RuntimeException{
    private String code;
    private String msg;

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

    public String getCode() {
        return code;
    }

    public String getMsg() {
        return msg;
    }
}

前置异常捕获
/**
 * 前置异常切面
 */
@Slf4j
@Aspect
@Component
public class ControllerAspect {

    @Pointcut("@annotation(org.springframework.web.bind.annotation.RequestMapping)" +
            "&&args(..,org.springframework.validation.BindingResult)")
    public void controllerAspect() {
    }

    @Around("controllerAspect()")
    public Object doBefore(ProceedingJoinPoint joinPoint) throws Throwable{
        Object[] args = joinPoint.getArgs();
        for (Object arg : args) {
            if (arg instanceof BindingResult) {
                BindingResult result = (BindingResult) arg;
                if (result.hasErrors()) {
                    log.error("请求参数校验错误");
                    FieldError fieldError = result.getFieldError();
                    if (fieldError != null) {
                        //return ResponseUtil.fail(new BizException("111111", fieldError.getDefaultMessage()));
                        throw new BizException("111111", fieldError.getDefaultMessage());
                    }
                    //return ResponseUtil.fail(new BizException("999999", "未知参数错误"));
                    throw new BizException("222222", "未知参数错误┭┮﹏┭┮");
                }
            }
        }
        return joinPoint.proceed();
    }
}
业务异常捕获
/**
 * Service异常捕获,将Service中的所有异常,转换为统一的BizException,方便ExceptionHandler统一处理
 */
@Aspect
public class ServiceAspect {
    @Pointcut("execution(public * com.example.exception.service.*.*(..))")
    public void serviceAspect() {
    }

    @Around("serviceAspect()")
    public Object doAround(ProceedingJoinPoint joinPoint) throws Throwable {
        try {
            return joinPoint.proceed();
        } catch (Exception e) {
            if (e instanceof BizException) {
                throw e;
            } else {
                throw new BizException("999999", "系统错误^_^");
            }
        }
    }
}
全局异常处理器
package com.example.exception.handler;

import com.example.exception.dto.ResponseEntity;
import com.example.exception.exception.BizException;
import com.example.exception.util.ResponseUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

@RestControllerAdvice
@Slf4j
public class GlobalExceptionHandler {
    /**
     * 业务异常处理
     */
    @ExceptionHandler(BizException.class)
    public ResponseEntity bizExceptionHandler(BizException e) {
        return ResponseUtil.fail(e);
    }

    /**
     * 通用异常处理
     */
    @ExceptionHandler(Exception.class)
    public ResponseEntity exceptionHandler(Exception e) {
        log.error(e.getMessage(), e);
        return ResponseUtil.fail("999999", "系统错误(#^.^#)");
    }
}

流程图参考

posted @ 2022-09-03 12:10  zomicc  阅读(150)  评论(0编辑  收藏  举报