Java tutorial
/* * Copyright 2013 JBoss Inc * * 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 org.overlord.commons.ui.header; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.io.Serializable; import java.util.ArrayList; import java.util.Collection; import java.util.Comparator; import java.util.Date; import java.util.List; import java.util.Properties; import java.util.TreeSet; import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.apache.commons.io.FileUtils; import org.apache.commons.io.IOUtils; import org.codehaus.jackson.JsonEncoding; import org.codehaus.jackson.JsonFactory; import org.codehaus.jackson.JsonGenerator; /** * This is a simple servlet that generates the javascript data used by the Overlord Header javascript. * * @author eric.wittmann@redhat.com */ public class OverlordHeaderDataJS extends HttpServlet { private static final long serialVersionUID = -4982770016769892713L; private String appId; private String logoutUrl; /** * Constructor. */ public OverlordHeaderDataJS() { } /** * @see javax.servlet.GenericServlet#init() */ @Override public void init() throws ServletException { ServletConfig config = getServletConfig(); appId = config.getInitParameter("app-id"); //$NON-NLS-1$ if (appId == null || appId.trim().length() == 0) { throw new ServletException( "Application identifier (app-id) parameter missing from Overlord Header Data JS servlet."); //$NON-NLS-1$ } logoutUrl = config.getInitParameter("logout-url"); //$NON-NLS-1$ if (logoutUrl == null || logoutUrl.trim().length() == 0) { logoutUrl = "?GLO=true"; //$NON-NLS-1$ } } /** * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest, * javax.servlet.http.HttpServletResponse) */ @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // Tell the browser to never cache this JavaScript (it's generated and includes // information like the currently logged-in user). noCache(response); // Now generate the JavaScript data (JSON) response.setContentType("text/javascript"); //$NON-NLS-1$ try { List<TabInfo> tabs = getTabs(request); response.getOutputStream().write("var OVERLORD_HEADER_DATA = ".getBytes("UTF-8")); //$NON-NLS-1$ //$NON-NLS-2$ JsonFactory f = new JsonFactory(); JsonGenerator g = f.createJsonGenerator(response.getOutputStream(), JsonEncoding.UTF8); g.useDefaultPrettyPrinter(); g.writeStartObject(); g.writeStringField("username", getRemoteUser(request)); //$NON-NLS-1$ g.writeStringField("logoutLink", getLogoutLink(request)); //$NON-NLS-1$ g.writeStringField("primaryBrand", getPrimaryBrand(tabs)); //$NON-NLS-1$ g.writeStringField("secondaryBrand", getSecondaryBrand(tabs)); //$NON-NLS-1$ g.writeArrayFieldStart("tabs"); //$NON-NLS-1$ for (TabInfo tabInfo : tabs) { g.writeStartObject(); g.writeStringField("app-id", tabInfo.appId); //$NON-NLS-1$ g.writeStringField("href", tabInfo.href); //$NON-NLS-1$ g.writeStringField("label", tabInfo.label); //$NON-NLS-1$ g.writeBooleanField("active", tabInfo.active); //$NON-NLS-1$ g.writeEndObject(); } g.writeEndArray(); g.writeEndObject(); g.flush(); response.getOutputStream().write(";".getBytes("UTF-8")); //$NON-NLS-1$ //$NON-NLS-2$ g.close(); } catch (Exception e) { throw new ServletException(e); } } /** * Gets the remote user, handles null. * @param request */ private String getRemoteUser(HttpServletRequest request) { return request.getRemoteUser() == null ? "<anonymous>" : request.getRemoteUser(); //$NON-NLS-1$ } /** * Gets the configured logout link. * @param request */ private String getLogoutLink(HttpServletRequest request) { return logoutUrl; } /** * Gets the primary brand from the currently active tab. * @param tabs */ private String getPrimaryBrand(List<TabInfo> tabs) { for (TabInfo tabInfo : tabs) { if (tabInfo.active) { return tabInfo.primaryBrand; } } return ""; //$NON-NLS-1$ } /** * Gets the secondary brand from the currently active tab. * @param tabs */ private String getSecondaryBrand(List<TabInfo> tabs) { for (TabInfo tabInfo : tabs) { if (tabInfo.active) { return tabInfo.secondaryBrand; } } return ""; //$NON-NLS-1$ } /** * Gets the tabs configured to appear in the UI. * @param request */ private List<TabInfo> getTabs(HttpServletRequest request) throws Exception { HttpSession session = request.getSession(); @SuppressWarnings("unchecked") List<TabInfo> tabs = (List<TabInfo>) session.getAttribute("overlord-tabs"); //$NON-NLS-1$ if (tabs == null) { tabs = new ArrayList<TabInfo>(); getConfiguredTabs(tabs); session.setAttribute("overlord-tabs", tabs); //$NON-NLS-1$ } return tabs; } /** * Reads any overlord header config files to determine which overlord applications * are currently deployed/configured. * @param tabs */ private void getConfiguredTabs(List<TabInfo> tabs) throws Exception { File configDir = getConfigDir(); if (configDir == null) return; TreeSet<TabInfo> sortedTabs = new TreeSet<TabInfo>(new Comparator<TabInfo>() { @Override public int compare(TabInfo o1, TabInfo o2) { return o1.appId.compareTo(o2.appId); } }); Collection<File> configFiles = FileUtils.listFiles(configDir, new String[] { "properties" }, false); //$NON-NLS-1$ for (File configFile : configFiles) { if (!configFile.getCanonicalPath().endsWith("-overlordapp.properties")) //$NON-NLS-1$ continue; FileReader reader = new FileReader(configFile); try { Properties configProps = new Properties(); configProps.load(new FileReader(configFile)); String appId = configProps.getProperty("overlordapp.app-id"); //$NON-NLS-1$ String href = configProps.getProperty("overlordapp.href"); //$NON-NLS-1$ // TODO need i18n support here - need different versions of the config files for each lang? String primaryBrand = configProps.getProperty("overlordapp.primary-brand"); //$NON-NLS-1$ String secondaryBrand = configProps.getProperty("overlordapp.secondary-brand"); //$NON-NLS-1$ String label = configProps.getProperty("overlordapp.label"); //$NON-NLS-1$ sortedTabs.add( new TabInfo(appId, primaryBrand, secondaryBrand, href, label, appId.equals(this.appId))); } finally { IOUtils.closeQuietly(reader); } } tabs.addAll(sortedTabs); } /** * Returns the directory to check for overlord-app config files. */ private File getConfigDir() { File configDir = null; // First, check for a configured system property String configDirProp = System.getProperty("org.overlord.apps.config-dir"); //$NON-NLS-1$ if (configDirProp != null) { configDir = new File(configDirProp); if (configDir.isDirectory()) { return configDir; } } // Next, check for JBoss String jbossConfigDir = System.getProperty("jboss.server.config.dir"); //$NON-NLS-1$ if (jbossConfigDir != null) { File dirFile = new File(jbossConfigDir); if (dirFile.isDirectory()) { configDir = new File(dirFile, "overlord-apps"); //$NON-NLS-1$ if (configDir.isDirectory()) { return configDir; } } } String jbossConfigUrl = System.getProperty("jboss.server.config.url"); //$NON-NLS-1$ if (jbossConfigUrl != null) { File dirFile = new File(jbossConfigUrl); if (dirFile.isDirectory()) { configDir = new File(dirFile, "overlord-apps"); //$NON-NLS-1$ if (configDir.isDirectory()) { return configDir; } } } String jbossDataDir = System.getProperty("jboss.server.data.dir"); //$NON-NLS-1$ if (jbossDataDir != null) { File dirFile = new File(jbossDataDir); if (dirFile.isDirectory()) { configDir = new File(dirFile, "overlord-apps"); //$NON-NLS-1$ if (configDir.isDirectory()) { return configDir; } } } // Now try tomcat String catalinaHomeDir = System.getProperty("catalina.home"); //$NON-NLS-1$ if (catalinaHomeDir != null) { File dirFile = new File(catalinaHomeDir, "conf"); //$NON-NLS-1$ if (dirFile.isDirectory()) { configDir = new File(dirFile, "overlord-apps"); //$NON-NLS-1$ if (configDir.isDirectory()) { return configDir; } } } // Now try karaf/fuse String karafDir = System.getProperty("karaf.home"); //$NON-NLS-1$ if (karafDir != null) { File dirFile = new File(karafDir, "etc"); //$NON-NLS-1$ if (dirFile.isDirectory()) { configDir = new File(dirFile, "overlord-apps"); //$NON-NLS-1$ if (configDir.isDirectory()) { return configDir; } } } // Now try jetty String jettyDir = System.getProperty("jetty.home"); //$NON-NLS-1$ if (jettyDir != null) { File dirFile = new File(jettyDir, "etc"); //$NON-NLS-1$ if (dirFile.isDirectory()) { configDir = new File(dirFile, "overlord-apps"); //$NON-NLS-1$ if (configDir.isDirectory()) { return configDir; } } } return null; } /** * Make sure to tell the browser not to cache it. * * @param response */ private void noCache(HttpServletResponse response) { Date now = new Date(); response.setDateHeader("Date", now.getTime()); //$NON-NLS-1$ // one day old response.setDateHeader("Expires", now.getTime() - 86400000L); //$NON-NLS-1$ response.setHeader("Pragma", "no-cache"); //$NON-NLS-1$ //$NON-NLS-2$ response.setHeader("Cache-control", "no-cache, no-store, must-revalidate"); //$NON-NLS-1$ //$NON-NLS-2$ } /** * A single tab in the UI. * @author eric.wittmann@redhat.com */ private static final class TabInfo implements Serializable { private static final long serialVersionUID = 7628110060136125387L; public final String appId; public final String primaryBrand; public final String secondaryBrand; public final String href; public final String label; public final boolean active; public TabInfo(String appId, String primaryBrand, String secondaryBrand, String href, String label, boolean active) { this.appId = appId; this.primaryBrand = primaryBrand; this.secondaryBrand = secondaryBrand; this.href = href; this.label = label; this.active = active; } } }