Springboot 異常處理

摘要： @ExceptionHandler 如何使用 可以用@ExceptionHandler 註解方法去處理異常情況，@ExceptionHandler註解可以在@Controller,@RestController,@ControllerAdvice,@RestControllerAdv...

@ExceptionHandler 如何使用

可以用@ExceptionHandler 註解方法去處理異常情況，@ExceptionHandler註解可以在@Controller,@RestController,@ControllerAdvice,@RestControllerAdvice中使用

在@RestController,@RestControllerAdvice註解的類中使用時方法會預設加上@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) {
// ...
}
}

上面的例子會預設捕獲Exception下所有的異常情況，如果需要更詳細的捕獲，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 方法支援的引數列表

方法引數型別	Description
Exception	異常的詳細情況
HandlerMethod	訪問異常發生的控制器方法的詳細情況
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’sMultipartRequest ,MultipartHttpServletRequest .
javax.servlet.http.HttpSession	Enforces the presence of a session. As a consequence, such an argument is nevernull .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 specificPrincipal implementation class if known.
HttpMethod	The HTTP method of the request.
java.util.Locale	The current request locale, determined by the most specificLocaleResolver available, in effect, the configuredLocaleResolver /LocaleContextResolver .
java.util.TimeZone +java.time.ZoneId	The time zone associated with the current request, as determined by aLocaleContextResolver .
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. SeeRedirect attributes andFlash 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 方法支援的返回型別說明

返回值型別	描述
@ResponseBody	加上@ResponseBody註解可以返回JSON內容
HttpEntity<B> ,ResponseEntity<B>	The return value specifies the full response including HTTP headers and body be converted throughHttpMessageConverter s and written to the response. SeeResponseEntity .
String	A view name to be resolved withViewResolver 's and used together with the implicit model — determined through command objects and@ModelAttribute methods. The handler method may also programmatically enrich the model by declaring aModel argument (see above).
View	AView 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 aModel 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 aRequestToViewNameTranslator .
@ModelAttribute	An attribute to be added to the model with the view name implicitly determined through aRequestToViewNameTranslator .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 avoid return type (ornull return value) is considered to have fully handled the response if it also has aServletResponse , or anOutputStream argument, or an@ResponseStatus annotation. The same is true also if the controller has made a positive ETag or lastModified timestamp check (seeControllers for details).If none of the above is true, avoid 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 byBeanUtils#isSimpleProperty in which case it remains unresolved.

參考連結

• 官網文件：https://docs.spring.io/spring/docs/5.0.12.RELEASE/spring-framework-reference/web.html#mvc-ann-exceptionhandler