Java tutorial
/* * Copyright (C) 2013 David Sowerby * * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * specific language governing permissions and limitations under the License. */ package uk.q3c.krail.core.shiro; import com.google.inject.Inject; import com.vaadin.server.DefaultErrorHandler; import com.vaadin.server.ErrorEvent; import org.apache.commons.lang3.exception.ExceptionUtils; import org.apache.shiro.authz.AuthorizationException; import org.apache.shiro.authz.UnauthenticatedException; import org.apache.shiro.authz.UnauthorizedException; import uk.q3c.krail.core.navigate.InvalidURIException; import uk.q3c.krail.core.navigate.InvalidURIExceptionHandler; import uk.q3c.krail.core.navigate.Navigator; import uk.q3c.krail.core.shiro.aop.NotAGuestException; import uk.q3c.krail.core.shiro.aop.NotAUserException; import uk.q3c.krail.core.user.notify.UserNotifier; import uk.q3c.krail.core.view.component.LoginFormException; /** * Extends the {@link DefaultErrorHandler} to intercept known V& exceptions, including Shiro related exceptions - * {@link UnauthorizedException} and {@link UnauthenticatedException}. Uses pluggable handlers for all caught * exceptions. * * @author David Sowerby 4 Jan 2013 */ public class KrailErrorHandler extends DefaultErrorHandler { private final UnauthenticatedExceptionHandler authenticationHandler; private final NotAGuestExceptionHandler notAGuestExceptionHandler; private final NotAUserExceptionHandler notAUserExceptionHandler; private final UnauthorizedExceptionHandler authorisationHandler; private final InvalidURIExceptionHandler invalidUriHandler; private final Navigator navigator; private UserNotifier userNotifier; @Inject protected KrailErrorHandler(UnauthenticatedExceptionHandler authenticationHandler, NotAGuestExceptionHandler notAGuestExceptionHandler, NotAUserExceptionHandler notAUserExceptionHandler, UnauthorizedExceptionHandler authorisationHandler, InvalidURIExceptionHandler invalidUriHandler, Navigator navigator, UserNotifier userNotifier) { super(); this.authenticationHandler = authenticationHandler; this.notAGuestExceptionHandler = notAGuestExceptionHandler; this.notAUserExceptionHandler = notAUserExceptionHandler; this.authorisationHandler = authorisationHandler; this.invalidUriHandler = invalidUriHandler; this.navigator = navigator; this.userNotifier = userNotifier; } @Override public void error(ErrorEvent event) { Throwable originalError = event.getThrowable(); // handle an attempt to navigate to an invalid page int invalidURI = ExceptionUtils.indexOfThrowable(originalError, InvalidURIException.class); if (invalidURI >= 0) { InvalidURIException e = (InvalidURIException) ExceptionUtils.getThrowables(originalError)[invalidURI]; invalidUriHandler.invoke(e); return; } // handle an unauthorised access attempt int unauthorised = ExceptionUtils.indexOfThrowable(originalError, UnauthorizedException.class); if (unauthorised >= 0) { authorisationHandler.invoke(); return; } // handle an unauthenticated access attempt int unauthenticated = ExceptionUtils.indexOfThrowable(originalError, UnauthenticatedException.class); if (unauthenticated >= 0) { authenticationHandler.invoke(); return; } int notAUser = ExceptionUtils.indexOfThrowable(originalError, NotAUserException.class); if (notAUser >= 0) { notAUserExceptionHandler.invoke(); return; } int notAGuest = ExceptionUtils.indexOfThrowable(originalError, NotAGuestException.class); if (notAGuest >= 0) { notAGuestExceptionHandler.invoke(); return; } // catch-all handle an unauthorised access attempt, exceptions are not always thrown at more specific level unauthorised = ExceptionUtils.indexOfThrowable(originalError, AuthorizationException.class); if (unauthorised >= 0) { authorisationHandler.invoke(); return; } // no handler identified, display the exception on the error page int loginEmpty = ExceptionUtils.indexOfThrowable(originalError, LoginFormException.class); if (loginEmpty > 0) { LoginFormException lfe = (LoginFormException) ExceptionUtils.getThrowableList(originalError) .get(loginEmpty); userNotifier.notifyWarning(lfe.getMsgKey(), lfe.getParams()); return; } navigator.error(event.getThrowable()); } }