spring boot 对请求进行全局异常处理

缺乏、安全感 2023-02-11 11:23 4阅读 0赞

**个人认为：如果不使用全局异常处理的话，那么会有很多异常都需要使用try catch进行捕获，重复代码增加，增加代码的恶心程度。**

###  controller层代码： ###

@RestController
    @RequestMapping(value = "/user")
    public class UserController {
    
        @Resource
        private UserService userService;
        
        @GetMapping(value = "get")
        public R getUser(@RequestParam(name = "id") Integer id) throws BusinessException {
            User user = userService.getUser(id);
            if (user == null) {
                throw new BusinessException(BusinessError.REQUEST_FAIL);
            }
            return R.common(new ErrorCode(BusinessError.REQUEST_SUCCESS.getErrCode(), BusinessError.REQUEST_SUCCESS.getErrMsg()));
        }
    }

**当请求参数错误，tomcat层会返回一个400的状态码和一个页面**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NDk1Nzg2_size_16_color_FFFFFF_t_70][]

**亦或是，输入一个不存在的请求路径，同样会返回一个页面，并且返回404状态码**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NDk1Nzg2_size_16_color_FFFFFF_t_70 1][]

**给到前端也没有办法去进行解析。**

**因此需要定义一个公共的异常处理拦截器，对不同的异常不同处理，并返回统一个格式给到前端，让前端对其解析。**

**定义一个全局异常处理器：**

**可以使用@RestControllerAdvice\+@ExceptionHandler结合使用；**

**如果使用@ControllerAdvice\+@ExceptionHandler的话，还需要在每个异常处理的方法上加上****@ResponseBody注解，否则返回的是页面。**

@Slf4j
    @RestControllerAdvice
    public class GlobalExceptionHandler {
    
        //自定义的业务异常
        @ExceptionHandler(BusinessException.class)
        public R doError(BusinessException e){
            log.error("BusinessException:{}",e);
            return R.common(e.getErrorCode());
        }
    
        //请求路径找不到
        @ExceptionHandler(NoHandlerFoundException.class)
        public R doError(NoHandlerFoundException e){
            log.error("NoHandlerFoundException:{}",e);
            return R.common(new ErrorCode(BusinessError.NO_HANDLER_FOUNT.getErrCode(),BusinessError.NO_HANDLER_FOUNT.getErrMsg()));
        }
    
        //请求参数错误异常
        @ExceptionHandler(MissingServletRequestParameterException.class)
        public R doError(MissingServletRequestParameterException e){
            log.error("MissingServletRequestParameterException:{}",e);
            return R.common(new ErrorCode(BusinessError.BIND_EXCEPTION_ERROR.getErrCode(),BusinessError.BIND_EXCEPTION_ERROR.getErrMsg()));
        }
    
        //上面异常都未捕获到的话，就会被这个给捕获到
        @ExceptionHandler(Exception.class)
        public R doError(Exception e){
            log.error("UNKNOWN:{}",e);
            return R.common(new ErrorCode(BusinessError.UNKNOWN.getErrCode(),BusinessError.UNKNOWN.getErrMsg()));
        }
    }

**加上全局异常处理器过后：测试 **

![20200523144009201.png][]

![20200523144021755.png][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NDk1Nzg2_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200523143100686.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NDk1Nzg2,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NDk1Nzg2_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200523143307681.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NDk1Nzg2,size_16,color_FFFFFF,t_70
[20200523144009201.png]: https://img-blog.csdnimg.cn/20200523144009201.png
[20200523144021755.png]: https://img-blog.csdnimg.cn/20200523144021755.png