1.介紹
在日常開發中發生了異常，往往是需要通過一個統一的異常處理處理所有異常，來保證客戶端能夠收到友好的提示。SpringBoot在頁面發生異常的時候會自動把請求轉到/error，SpringBoot內置了一個BasicErrorController對異常進行統一的處理，當然也可以自定義這個路徑
application.yaml
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server: port: 8080 error: path: /custom/error |
BasicErrorController提供兩種返回錯誤一種是頁面返回、當你是頁面請求的時候就會返回頁面，另外一種是json請求的時候就會返回json錯誤
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@RequestMapping(produces = "text/html")public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) { HttpStatus status = getStatus(request); Map<String, Object> model = Collections.unmodifiableMap(getErrorAttributes( request, isIncludeStackTrace(request, MediaType.TEXT_HTML))); response.setStatus(status.value()); ModelAndView modelAndView = resolveErrorView(request, response, status, model); return (modelAndView == null ? new ModelAndView("error", model) : modelAndView);}@RequestMapping@ResponseBodypublic ResponseEntity<Map<String, Object>> error(HttpServletRequest request) { Map<String, Object> body = getErrorAttributes(request, isIncludeStackTrace(request, MediaType.ALL)); HttpStatus status = getStatus(request); return new ResponseEntity<Map<String, Object>>(body, status);} |
分別會有如下兩種返回
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{ "timestamp": 1478571808052, "status": 404, "error": "Not Found", "message": "No message available", "path": "/rpc"} |
2.通用Exception處理
通過使用@ControllerAdvice來進行統一異常處理，@ExceptionHandler(value = Exception.class)來指定捕獲的異常
下面針對兩種異常進行了特殊處理分別返回頁面和json數據，使用這種方式有個局限，無法根據不同的頭部返回不同的數據格式，而且無法針對404、403等多種狀態進行處理
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@ControllerAdvicepublic class GlobalExceptionHandler { public static final String DEFAULT_ERROR_VIEW = "error"; @ExceptionHandler(value = CustomException.class) @ResponseBody public ResponseEntity defaultErrorHandler(HttpServletRequest req, CustomException e) throws Exception { return ResponseEntity.ok("ok"); } @ExceptionHandler(value = Exception.class) public ModelAndView defaultErrorHandler(HttpServletRequest req, Exception e) throws Exception { ModelAndView mav = new ModelAndView(); mav.addObject("exception", e); mav.addObject("url", req.getRequestURL()); mav.setViewName(DEFAULT_ERROR_VIEW); return mav; }} |
3.自定義BasicErrorController 錯誤處理
在初始介紹哪里提到了BasicErrorController，這個是SpringBoot的默認錯誤處理，也是一種全局處理方式。咱們可以模仿這種處理方式自定義自己的全局錯誤處理
下面定義了一個自己的BasicErrorController，可以根據自己的需求自定義errorHtml()和error()的返回值。
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@Controller@RequestMapping("${server.error.path:${error.path:/error}}")public class BasicErrorController extends AbstractErrorController { private final ErrorProperties errorProperties; private static final Logger LOGGER = LoggerFactory.getLogger(BasicErrorController.class); @Autowired private ApplicationContext applicationContext; /** * Create a new {@link org.springframework.boot.autoconfigure.web.BasicErrorController} instance. * * @param errorAttributes the error attributes * @param errorProperties configuration properties */ public BasicErrorController(ErrorAttributes errorAttributes, ErrorProperties errorProperties) { this(errorAttributes, errorProperties, Collections.<ErrorViewResolver>emptyList()); } /** * Create a new {@link org.springframework.boot.autoconfigure.web.BasicErrorController} instance. * * @param errorAttributes the error attributes * @param errorProperties configuration properties * @param errorViewResolvers error view resolvers */ public BasicErrorController(ErrorAttributes errorAttributes, ErrorProperties errorProperties, List<ErrorViewResolver> errorViewResolvers) { super(errorAttributes, errorViewResolvers); Assert.notNull(errorProperties, "ErrorProperties must not be null"); this.errorProperties = errorProperties; } @Override public String getErrorPath() { return this.errorProperties.getPath(); } @RequestMapping(produces = "text/html") public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) { HttpStatus status = getStatus(request); Map<String, Object> model = Collections.unmodifiableMap(getErrorAttributes( request, isIncludeStackTrace(request, MediaType.TEXT_HTML))); response.setStatus(status.value()); ModelAndView modelAndView = resolveErrorView(request, response, status, model); insertError(request); return modelAndView == null ? new ModelAndView("error", model) : modelAndView; } @RequestMapping @ResponseBody public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) { Map<String, Object> body = getErrorAttributes(request, isIncludeStackTrace(request, MediaType.ALL)); HttpStatus status = getStatus(request); insertError(request); return new ResponseEntity(body, status); } /** * Determine if the stacktrace attribute should be included. * * @param request the source request * @param produces the media type produced (or {@code MediaType.ALL}) * @return if the stacktrace attribute should be included */ protected boolean isIncludeStackTrace(HttpServletRequest request, MediaType produces) { ErrorProperties.IncludeStacktrace include = getErrorProperties().getIncludeStacktrace(); if (include == ErrorProperties.IncludeStacktrace.ALWAYS) { return true; } if (include == ErrorProperties.IncludeStacktrace.ON_TRACE_PARAM) { return getTraceParameter(request); } return false; } /** * Provide access to the error properties. * * @return the error properties */ protected ErrorProperties getErrorProperties() { return this.errorProperties; }} |
SpringBoot提供了一種特殊的Bean定義方式，可以讓我們容易的覆蓋已經定義好的Controller,原生的BasicErrorController是定義在ErrorMvcAutoConfiguration中的
具體代碼如下：
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@Bean@ConditionalOnMissingBean(value = ErrorController.class, search = SearchStrategy.CURRENT)public BasicErrorController basicErrorController(ErrorAttributes errorAttributes) { return new BasicErrorController(errorAttributes, this.serverProperties.getError(), this.errorViewResolvers);} |
可以看到這個注解@ConditionalOnMissingBean 意思就是定義這個bean 當 ErrorController.class 這個沒有定義的時候， 意思就是說只要我們在代碼里面定義了自己的ErrorController.class時，這段代碼就不生效了，具體自定義如下：
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@Configuration@ConditionalOnWebApplication@ConditionalOnClass({Servlet.class, DispatcherServlet.class})@AutoConfigureBefore(WebMvcAutoConfiguration.class)@EnableConfigurationProperties(ResourceProperties.class)public class ConfigSpringboot { @Autowired(required = false) private List<ErrorViewResolver> errorViewResolvers; private final ServerProperties serverProperties; public ConfigSpringboot( ServerProperties serverProperties) { this.serverProperties = serverProperties; } @Bean public MyBasicErrorController basicErrorController(ErrorAttributes errorAttributes) { return new MyBasicErrorController(errorAttributes, this.serverProperties.getError(), this.errorViewResolvers); }} |
在使用的時候需要注意MyBasicErrorController不能被自定義掃描Controller掃描到，否則無法啟動。
3.總結
一般來說自定義BasicErrorController這種方式比較實用，因為可以通過不同的頭部返回不同的數據格式，在配置上稍微復雜一些，但是從實用的角度來說比較方便而且可以定義通用組件
本文代碼：SpringBoot-Learn.rar
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持服務器之家。
原文鏈接：http://blog.csdn.net/king_is_everyone/article/details/53080851
