使用@ControllerAdvice如何返回给前端对应错误码-蒲公英云

使用@ControllerAdvice如何返回给前端对应错误码

水深无声 2022-03-02 11:30 469阅读 0赞

@ControllerAdvice可以捕获spring应用下面未被捕获异常，下面是常见代码：

@ExceptionHandler(value = Exception.class)  
@**ResponseStatus**(HttpStatus.INTERNAL\_SERVER\_ERROR)  
public String errorHandler(Exception ex) \{  
    ApiResultVo<String> resultVo = new ApiResultVo<>();  
    resultVo.setErrorCode(500);  
    resultVo.setErrorMsg(ex.getMessage());  
    return JSON.toJSONString(resultVo);  
\}  
@ExceptionHandler(value = MyException.class)  
@**ResponseStatus**(HttpStatus.INTERNAL\_SERVER\_ERROR)  
public String myExceptionHandler(MyException ex) \{  
    ApiResultVo<String> resultVo = new ApiResultVo<>();  
    resultVo.setErrorCode(401);  
    resultVo.setErrorMsg(ex.getMessage());  
    return JSON.toJSONString(resultVo);  
\}

我们在对应异常处理的上面加上ResponseStatus注解就能将系统异常转换为对应的Http状态码，这部分工作由ResponseStatusExceptionResolver这个类完成，下面是关键代码：

protected ModelAndView doResolveException(HttpServletRequest request, HttpServletResponse response,  
        Object handler, Exception ex) \{
    ResponseStatus responseStatus = AnnotatedElementUtils.findMergedAnnotation(ex.getClass(), ResponseStatus.class);  
    if (responseStatus != null) \{  
        try \{  
            return **resolveResponseStatus**(responseStatus, request, response, handler, ex);  
        \}  
        catch (Exception resolveEx) \{  
            logger.warn("Handling of @ResponseStatus resulted in Exception", resolveEx);  
        \}  
    \}  
    else if (ex.getCause() instanceof Exception) \{  
        ex = (Exception) ex.getCause();  
        return doResolveException(request, response, handler, ex);  
    \}  
    return null;  
\}
protected ModelAndView **resolveResponseStatus**(ResponseStatus responseStatus, HttpServletRequest request,  
        HttpServletResponse response, Object handler, Exception ex) throws Exception \{
    int statusCode = responseStatus.code().value();  
    String reason = responseStatus.reason();  
    if (!StringUtils.hasLength(reason)) \{  
        **response.sendError**(statusCode);  
    \}  
    else \{  
        String resolvedReason = (this.messageSource != null ?  
                this.messageSource.getMessage(reason, null, reason, LocaleContextHolder.getLocale()) :  
                reason);  
        response.sendError(statusCode, resolvedReason);  
    \}  
    return new ModelAndView();  
\}