Springboot 异常处理

@ExceptionHandler 如何使用

可以用@ExceptionHandler 注解方法去处理异常情况，@ExceptionHandler注解可以在@Controller,@RestController,@ControllerAdvice,@RestControllerAdvice中使用
在@RestController,@RestControllerAdvice注解的类中使用时方法会默认加上@ResponseBody

FOR EXAMPLE:

@Controller
public class SimpleController {
    @ExceptionHandler
    public ResponseEntity<String> handle(IOException ex) {
        // ...
    }
}

@ControllerAdvice(annotations = RestController.class)
public class ExampleAdvice1 {
	@ExceptionHandler
    public ResponseEntity<String> handle(IOException ex) {
        // ...
    }
}

上面的例子会默认捕获Exception下所有的异常情况，如果需要更详细的捕获，可以用如下方式

FOR EXAMPLE:

    @ExceptionHandler(BindException.class)
    public ResponseEntity<String> handle(BindException ex) {
        // ...
    }    
	@ExceptionHandler({RemoteException.class,FileSystemException.class})
    public ResponseEntity<String> handle(Exception ex) {
        // ...
    }

@ExceptionHandler 方法支持的参数列表

方法参数类型	Description
Exception	异常的详细情况
HandlerMethod	访问异常发生的控制器方法的详细情况
WebRequest, NativeWebRequest	Generic access to request parameters, request & session attributes, without direct use of the Servlet API.
javax.servlet.ServletRequest, javax.servlet.ServletResponse	Choose any specific request or response type — e.g. ServletRequest, HttpServletRequest, or Spring’s MultipartRequest, MultipartHttpServletRequest.
javax.servlet.http.HttpSession	Enforces the presence of a session. As a consequence, such an argument is never null. Note: Session access is not thread-safe. Consider setting theRequestMappingHandlerAdapter's "synchronizeOnSession" flag to "true" if multiple requests are allowed to access a session concurrently.
java.security.Principal	Currently authenticated user; possibly a specific Principal implementation class if known.
HttpMethod	The HTTP method of the request.
java.util.Locale	The current request locale, determined by the most specific LocaleResolveravailable, in effect, the configured LocaleResolver/LocaleContextResolver.
java.util.TimeZone + java.time.ZoneId	The time zone associated with the current request, as determined by a LocaleContextResolver.
java.io.OutputStream, java.io.Writer	For access to the raw response body as exposed by the Servlet API.
java.util.Map, org.springframework.ui.Model, org.springframework.ui.ModelMap	For access to the model for an error response, always empty.
RedirectAttributes	Specify attributes to use in case of a redirect — i.e. to be appended to the query string, and/or flash attributes to be stored temporarily until the request after redirect. See Redirect attributes and Flash attributes.
@SessionAttribute	For access to any session attribute; in contrast to model attributes stored in the session as a result of a class-level @SessionAttributes declaration. See@SessionAttribute for more details.
@RequestAttribute	For access to request attributes. See @RequestAttribute for more details.

@ExceptionHandler 方法支持的返回类型说明

返回值类型	描述
@ResponseBody	加上@ResponseBody注解可以返回JSON内容
HttpEntity<B>, ResponseEntity<B>	The return value specifies the full response including HTTP headers and body be converted through HttpMessageConverters and written to the response. See ResponseEntity.
String	A view name to be resolved with ViewResolver's and used together with the implicit model — determined through command objects and @ModelAttributemethods. The handler method may also programmatically enrich the model by declaring a Model argument (see above).
View	A View instance to use for rendering together with the implicit model — determined through command objects and @ModelAttribute methods. The handler method may also programmatically enrich the model by declaring a Model argument (see above).
java.util.Map, org.springframework.ui.Model	Attributes to be added to the implicit model with the view name implicitly determined through a RequestToViewNameTranslator.
@ModelAttribute	An attribute to be added to the model with the view name implicitly determined through a RequestToViewNameTranslator.Note that @ModelAttribute is optional. See "Any other return value" further below in this table.
ModelAndView object	The view and model attributes to use, and optionally a response status.
void	A method with a void return type (or null return value) is considered to have fully handled the response if it also has a ServletResponse, or an OutputStreamargument, or an @ResponseStatus annotation. The same is true also if the controller has made a positive ETag or lastModified timestamp check (see Controllers for details).If none of the above is true, a void return type may also indicate "no response body" for REST controllers, or default view name selection for HTML controllers.
Any other return value	If a return value is not matched to any of the above, by default it is treated as a model attribute to be added to the model, unless it is a simple type, as determined by BeanUtils#isSimpleProperty in which case it remains unresolved.

参考链接

• 官网文档：https://docs.spring.io/spring/docs/5.0.12.RELEASE/spring-framework-reference/web.html#mvc-ann-exceptionhandler