默認效果：
1）、瀏覽器，返回一個默認的錯誤頁面
1.1 請求頭
1.2返回結果
2）、如果是其他客戶端，默認響應一個json數據
2.1請求頭
2.2返回結果
{ "timestamp": "2018-11-25T08:22:36.343+0000", "status": 404, "error": "Not Found", "message": "No message available", "path": "/golden" }
步驟：
1）系統出現4xx或者5xx之類的錯誤；ErrorPageCustomizer就會生效（定制錯誤的響應規則）；
2） 根據相應規則來到/error請求；被BasicErrorController處理；
3）響應頁面；被Controller處理后去哪個頁面是由DefaultErrorViewResolver解析得到的；
源碼解析
public class ErrorMvcAutoConfiguration {
// 系統出現錯誤以后來到error請求進行處理；（相當於web.xml注冊錯誤頁面規則） @Bean public ErrorPageCustomizer errorPageCustomizer() { return new ErrorPageCustomizer(this.serverProperties, this.dispatcherServletPath); } /** * {@link WebServerFactoryCustomizer} that configures the server's error pages. */ private static class ErrorPageCustomizer implements ErrorPageRegistrar, Ordered { private final ServerProperties properties; private final DispatcherServletPath dispatcherServletPath; protected ErrorPageCustomizer(ServerProperties properties, DispatcherServletPath dispatcherServletPath) { this.properties = properties; this.dispatcherServletPath = dispatcherServletPath; } @Override public void registerErrorPages(ErrorPageRegistry errorPageRegistry) { ErrorPage errorPage = new ErrorPage(this.dispatcherServletPath .getRelativePath(this.properties.getError().getPath())); errorPageRegistry.addErrorPages(errorPage); } @Override public int getOrder() { return 0; } } } public class ErrorProperties { /** * Path of the error controller. */ @Value("${error.path:/error}") private String path = "/error"; }
public class ErrorMvcAutoConfiguration { // 系統出現錯誤以后來到error請求進行處理；（相當於web.xml注冊錯誤頁面規則） @Bean public ErrorPageCustomizer errorPageCustomizer() { return new ErrorPageCustomizer(this.serverProperties, this.dispatcherServletPath); } /** * {@link WebServerFactoryCustomizer} that configures the server's error pages. */ private static class ErrorPageCustomizer implements ErrorPageRegistrar, Ordered { private final ServerProperties properties; private final DispatcherServletPath dispatcherServletPath; protected ErrorPageCustomizer(ServerProperties properties, DispatcherServletPath dispatcherServletPath) { this.properties = properties; this.dispatcherServletPath = dispatcherServletPath; } @Override public void registerErrorPages(ErrorPageRegistry errorPageRegistry) { ErrorPage errorPage = new ErrorPage(this.dispatcherServletPath .getRelativePath(this.properties.getError().getPath())); errorPageRegistry.addErrorPages(errorPage); } @Override public int getOrder() { return 0; } } @Configuration @ConditionalOnProperty(prefix = "server.error.whitelabel", name = "enabled", matchIfMissing = true) @Conditional(ErrorTemplateMissingCondition.class) protected static class WhitelabelErrorViewConfiguration { //默認的SpringBoot錯誤頁面 private final SpelView defaultErrorView = new SpelView( "<html><body><h1>Whitelabel Error Page</h1>" + "<p>This application has no explicit mapping for /error, so you are seeing this as a fallback.</p>" + "<div id='created'>${timestamp}</div>" + "<div>There was an unexpected error (type=${error}, status=${status}).</div>" + "<div>${message}</div></body></html>"); @Bean(name = "error") @ConditionalOnMissingBean(name = "error") public View defaultErrorView() { return this.defaultErrorView; } // If the user adds @EnableWebMvc then the bean name view resolver from // WebMvcAutoConfiguration disappears, so add it back in to avoid disappointment. @Bean @ConditionalOnMissingBean public BeanNameViewResolver beanNameViewResolver() { BeanNameViewResolver resolver = new BeanNameViewResolver(); resolver.setOrder(Ordered.LOWEST_PRECEDENCE - 10); return resolver; } } } public class ErrorProperties { /** * Path of the error controller. */ @Value("${error.path:/error}") private String path = "/error"; }
public class ErrorMvcAutoConfiguration { @Bean @ConditionalOnMissingBean(value = ErrorController.class, search = SearchStrategy.CURRENT) public BasicErrorController basicErrorController(ErrorAttributes errorAttributes) { return new BasicErrorController(errorAttributes, this.serverProperties.getError(), this.errorViewResolvers); } } public abstract class AbstractErrorController implements ErrorController { private final ErrorAttributes errorAttributes; private final List<ErrorViewResolver> errorViewResolvers; public AbstractErrorController(ErrorAttributes errorAttributes) { this(errorAttributes, null); } //解析錯誤頁面 protected ModelAndView resolveErrorView(HttpServletRequest request, HttpServletResponse response, HttpStatus status, Map<String, Object> model) { for (ErrorViewResolver resolver : this.errorViewResolvers) { ModelAndView modelAndView = resolver.resolveErrorView(request, status, model); if (modelAndView != null) { return modelAndView; } } return null; } } /**取出配置項：server.error.path中的值。如果沒有，則取error.path的值，如果還沒有，則默認為/error路徑*/ @Controller @RequestMapping("${server.error.path:${error.path:/error}}") public class BasicErrorController extends AbstractErrorController { @RequestMapping(produces = "text/html")//產生html類型的數據；瀏覽器發送的請求來到這個方法處理 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()); //去哪個頁面作為錯誤頁面；包含頁面地址和頁面內容 ModelAndView modelAndView = resolveErrorView(request, response, status, model);
//如果為空，返回error視圖（在ErrorMvcConfiguration中配置的@Bean） return (modelAndView != null) ? modelAndView : new ModelAndView("error", model); } //產生json數據，其他客戶端來到這個方法處理； @RequestMapping @ResponseBody public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) { Map<String, Object> body = getErrorAttributes(request, isIncludeStackTrace(request, MediaType.ALL)); HttpStatus status = getStatus(request); return new ResponseEntity<>(body, status); } } public class DefaultErrorViewResolver implements ErrorViewResolver, Ordered { private static final Map<Series, String> SERIES_VIEWS;
private final ResourceProperties resourceProperties; static { Map<Series, String> views = new EnumMap<>(Series.class); views.put(Series.CLIENT_ERROR, "4xx"); views.put(Series.SERVER_ERROR, "5xx"); SERIES_VIEWS = Collections.unmodifiableMap(views); } @Override public ModelAndView resolveErrorView(HttpServletRequest request, HttpStatus status, Map<String, Object> model) { ModelAndView modelAndView = resolve(String.valueOf(status), model); if (modelAndView == null && SERIES_VIEWS.containsKey(status.series())) { modelAndView = resolve(SERIES_VIEWS.get(status.series()), model); } return modelAndView; } private ModelAndView resolve(String viewName, Map<String, Object> model) {
//默認SpringBoot可以去找到一個頁面？ error/404 String errorViewName = "error/" + viewName;
//模板引擎可以解析這個頁面地址就用模板引擎解析 TemplateAvailabilityProvider provider = this.templateAvailabilityProviders .getProvider(errorViewName, this.applicationContext); if (provider != null) {
//模板引擎可用的情況下返回到errorViewName指定的視圖地址 return new ModelAndView(errorViewName, model); }
//模板引擎不可用 return resolveResource(errorViewName, model); } // private ModelAndView resolveResource(String viewName, Map<String, Object> model) {
//從靜態資源文件夾下解析對應的頁面 error/404.html for (String location : this.resourceProperties.getStaticLocations()) { try { Resource resource = this.applicationContext.getResource(location); resource = resource.createRelative(viewName + ".html"); if (resource.exists()) { return new ModelAndView(new HtmlResourceView(resource), model); } } catch (Exception ex) { } } return null; } }
靜態資源文件夾路徑
@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false) public class ResourceProperties { private static final String[] CLASSPATH_RESOURCE_LOCATIONS = { "classpath:/META-INF/resources/", "classpath:/resources/", "classpath:/static/", "classpath:/public/" }; /** * Locations of static resources. Defaults to classpath:[/META-INF/resources/, * /resources/, /static/, /public/]. */ private String[] staticLocations = CLASSPATH_RESOURCE_LOCATIONS; }
2）、如果定制錯誤響應
1、如何定制錯誤的頁面
1）、有模板引擎的情況下；error/狀態碼; 【將錯誤頁面命名為 錯誤狀態碼.html 放在模板引擎文件夾里面的error文件夾下】，發生此狀態碼的錯誤就會來到 對應的頁面；
我們可以使用4xx和5xx作為錯誤頁面的文件名來匹配這種類型的所有錯誤，精確優先（優先尋找精確的狀態碼.html）；
頁面能獲取的信息：
timestamp：時間戳
status：狀態碼
error：錯誤提示
exception：異常對象
message：異常消息
errors：JSR303數據校驗的錯誤都在這里
2）、沒有模板引擎（模板引擎找不到這個錯誤頁面），靜態資源文件夾下找
3）、以上都沒有錯誤頁面，就是默認來到SpringBoot默認的錯誤提示頁面
2、如何定制錯誤的json數據；
1）、自定義異常處理&返回定制json數據；
一、頁面請求出錯
1. 自定義異常：
public class UserNotExistException extends RuntimeException { private static final long serialVersionUID = -7200824453209817228L; public UserNotExistException() { super("用戶不存在"); } }
2. Controller調用
@Controller public class HelloController { @RequestMapping("/hello") @ResponseBody public String createInvoice(@RequestParam("user") String user) { if(user.equals("aaa")) { throw new UserNotExistException(); } return "hello world"; } }
3. 5xx.html
<!DOCTYPE html> <html xmlns:th="http://www.thymeleaf.org"> <head> <meta charset="UTF-8"> <title>5xx.html</title> </head> <body> timestamp:[[${timestamp}]] <br> status:[[${status}]] <br> error:[[${error}]] <br> exception:[[${exception}]] <br> errors:[[${errors}]] <br> message:[[${message}]] <br> </body> </html>
4. 正確結果
5. 錯誤結果
二、json錯誤定制
1.編寫異常處理器
@ControllerAdvice public class MyExceptionHandler { //1、瀏覽器客戶端返回的都是json @ResponseBody @ExceptionHandler(UserNotExistException.class) public Map<String,Object> handleException(Exception e){ Map<String,Object> map = new HashMap<>(); map.put("code","user.notexist"); map.put("message",e.getMessage()); return map; } }
請求：
頁面也顯示json數據
但若想讓瀏覽器返回錯誤頁面，客戶端返回json數據，且是自適應的，怎么辦呢？
源碼解析
@Controller @RequestMapping("${server.error.path:${error.path:/error}}") public class BasicErrorController extends AbstractErrorController { @RequestMapping(produces = MediaType.TEXT_HTML_VALUE) public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) { HttpStatus status = getStatus(request); //status就是端口號 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) ? modelAndView : new ModelAndView("error", model); } } public abstract class AbstractErrorController implements ErrorController {
protected HttpStatus getStatus(HttpServletRequest request) { Integer statusCode = (Integer) request .getAttribute("javax.servlet.error.status_code"); if (statusCode == null) { return HttpStatus.INTERNAL_SERVER_ERROR; } try { return HttpStatus.valueOf(statusCode); } catch (Exception ex) { return HttpStatus.INTERNAL_SERVER_ERROR; } } }
@ControllerAdvice public class MyExceptionHandler { @ExceptionHandler(UserNotExistException.class) public String handleException(Exception e, HttpServletRequest request){ Map<String,Object> map = new HashMap<>(); //傳入我們自己的錯誤狀態碼 4xx 5xx /** * Integer statusCode = (Integer) request .getAttribute("javax.servlet.error.status_code"); */ request.setAttribute("javax.servlet.error.status_code",500); map.put("code","user.notexist"); map.put("message","用戶出錯啦"); request.setAttribute("ext",map); //下面自定義異常返回結果時，將獲取到此request作用域中的數據 //轉發到/error return "forward:/error"; } }
但是這種方式無法返回map對象里自定義的數據到頁面
Spring Boot 默認的實現原理如下：
public class BasicErrorController extends AbstractErrorController {
//SpringBoot 默認的返回錯誤html頁面代碼 @RequestMapping(produces = MediaType.TEXT_HTML_VALUE) 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) ? modelAndView : new ModelAndView("error", model); }
//Spring Boot 默認的返回json數據請求 @RequestMapping public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) { Map<String, Object> body = getErrorAttributes(request, isIncludeStackTrace(request, MediaType.ALL)); HttpStatus status = getStatus(request); return new ResponseEntity<>(body, status); } }
public abstract class AbstractErrorController implements ErrorController { private final ErrorAttributes errorAttributes; protected Map<String, Object> getErrorAttributes(HttpServletRequest request, boolean includeStackTrace) { WebRequest webRequest = new ServletWebRequest(request); return this.errorAttributes.getErrorAttributes(webRequest, includeStackTrace); } } @Order(Ordered.HIGHEST_PRECEDENCE) public class DefaultErrorAttributes implements ErrorAttributes, HandlerExceptionResolver, Ordered { @Override public Map<String, Object> getErrorAttributes(WebRequest webRequest, boolean includeStackTrace) { Map<String, Object> errorAttributes = new LinkedHashMap<>(); errorAttributes.put("timestamp", new Date()); addStatus(errorAttributes, webRequest); addErrorDetails(errorAttributes, webRequest, includeStackTrace); addPath(errorAttributes, webRequest); return errorAttributes; } }
3）、將我們的定制數據攜帶出去
出現錯誤以后，會來到/error請求，會被BasicErrorController處理，響應出去可以獲取的數據是由
getErrorAttributes得到的（是AbstractErrorController（ErrorController）規定的方法）；
1、完全來編寫一個ErrorController的實現類【或者是編寫AbstractErrorController的子類】，放在容器中；
2、頁面上能用的數據，或者是json返回能用的數據都是通過errorAttributes.getErrorAttributes得到；
容器中DefaultErrorAttributes.getErrorAttributes()；默認進行數據處理的；
@AutoConfigureBefore(WebMvcAutoConfiguration.class) @EnableConfigurationProperties({ ServerProperties.class, ResourceProperties.class,WebMvcProperties.class }) public class ErrorMvcAutoConfiguration { private final ServerProperties serverProperties; //當容器中沒有ErrorAttributes類型的bean時，才走默認的，所以我們自定義ErrorAttributes的實現類就可以實現定制化 @Bean @ConditionalOnMissingBean(value = ErrorAttributes.class, search = SearchStrategy.CURRENT) public DefaultErrorAttributes errorAttributes() { return new DefaultErrorAttributes( this.serverProperties.getError().isIncludeException()); } }
Spring Boot1.5.10版本
//給容器中加入我們自己定義的ErrorAttributes,用其實現類，避免重寫多個無需改造的方法 @Component public class MyErrorAttributes extends DefaultErrorAttributes { @Override public Map<String, Object> getErrorAttributes(RequestAttributes requestAttributes,boolean includeStackTrace) { Map<String, Object> map = super.getErrorAttributes(requestAttributes,includeStackTrace); map.put("company","everjiankang"); //自定義屬性
map.put("name","超軼絕塵"); return map; } }
Spring Boot 2.0 版本
import java.util.Map;
// import org.springframework.boot.web.servlet.error.DefaultErrorAttributes; servlet的可以成功執行 //import org.springframework.boot.web.reactive.error.DefaultErrorAttributes; reactive 也有這個類，但是執行不了 import org.springframework.stereotype.Component; import org.springframework.web.context.request.WebRequest; @Component public class MyErrorAttributes extends DefaultErrorAttributes{ @Override public Map<String, Object> getErrorAttributes(WebRequest webRequest, boolean includeStackTrace) {
//獲取到上文中異常處理類中設置到request作用域中的“ext”屬性 requeste.setAtrribute("exgt",map);
Map<String,Object> extMap = (Map<String, Object) webRequest.getAttribute("ext", RequestAttributes.SCOPE_REQUEST);
Map<String,Object> map = super.getErrorAttributes(webRequest, includeStackTrace); map.put("name", "xiaochao");
map.put("ext", extMap); //將異常處理類中的自定義信息返回給頁面
return map; } }
public interface WebRequest extends RequestAttributes {
}
public interface RequestAttributes {
int SCOPE_REQUEST = 0;
int SCOPE_SESSION = 1;
}
Spring Webflux 版本，執行未成功
在Spring boot 2.1.0版本中，第一個參數變成了org.springframework.web.reactive.function.server.ServerRequest類型，需要引入jar包
但是此段代碼不能適用。如何自定義詳情查看Spring Boot官方文檔
Spring 5 之 Spring Webflux 開發 Reactive 應用
<!-- 此依賴 會依賴於Netty --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-webflux</artifactId> <!--【改】增加“flux”四個字符--> </dependency>
//import org.springframework.boot.web.reactive.error.DefaultErrorAttributes; reactive 也有這個類，但是執行不了