Java tutorial
/* * Copyright 2000-2018 Vaadin Ltd. * * 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 com.vaadin.server; import com.vaadin.shared.ui.ErrorLevel; /** * <code>SystemError</code> is an error message for a problem caused by error in * system, not the user application code. The system error can contain technical * information such as stack trace and exception. * * SystemError does not support HTML in error messages or stack traces. If HTML * messages are required, use {@link UserError} or a custom implementation of * {@link ErrorMessage}. * * @author Vaadin Ltd. * @since 3.0 */ @SuppressWarnings("serial") public class SystemError extends AbstractErrorMessage { /** * Constructor for SystemError with error message specified. * * @param message * the Textual error description. */ public SystemError(String message) { super(message); setErrorLevel(ErrorLevel.SYSTEM); setMode(ContentMode.HTML); setMessage(getHtmlMessage()); } /** * Constructor for SystemError with causing exception and error message. * * @param message * the Textual error description. * @param cause * the throwable causing the system error. */ public SystemError(String message, Throwable cause) { this(message); addCause(AbstractErrorMessage.getErrorMessageForException(cause)); } /** * Constructor for SystemError with cause. * * @param cause * the throwable causing the system error. */ public SystemError(Throwable cause) { this(null, cause); } /** * Returns the message of the error in HTML. * * Note that this API may change in future versions. */ protected String getHtmlMessage() { // TODO wrapping div with namespace? See the old code: // target.addXMLSection("div", message, // "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"); StringBuilder sb = new StringBuilder(); if (getMessage() != null) { sb.append("<h2>"); sb.append(VaadinServlet.safeEscapeForHtml(getMessage())); sb.append("</h2>"); } return sb.toString(); } }