Java tutorial
/* Copyright (C) 2016 maik.jablonski@jease.org This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ package jease.cms.web.servlet; import java.io.IOException; import java.util.Comparator; import java.util.HashSet; import java.util.List; import java.util.Locale; import java.util.Set; import java.util.function.Function; import java.util.function.Supplier; import java.util.regex.Pattern; import javax.servlet.DispatcherType; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.annotation.WebFilter; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import jease.Names; import jease.Registry; import jease.cmf.domain.Node; import jease.cmf.service.Nodes; import jease.cms.domain.Redirect; import jfix.db4o.Database; import jfix.servlet.ResponseRewriter; import jfix.servlet.Servlets; import org.apache.commons.lang3.StringUtils; @WebFilter(urlPatterns = { "/*" }, dispatcherTypes = { DispatcherType.REQUEST, DispatcherType.FORWARD, DispatcherType.INCLUDE, DispatcherType.ERROR }) public class JeaseController implements javax.servlet.Filter { private static Supplier<List<Redirect>> redirectSupplier = () -> { List<Redirect> redirects = Database.query(Redirect.class); redirects.sort(Comparator.comparing(Redirect::getTimestamp)); return redirects; }; private static Supplier<Function<String, String>> rewriterSupplier = () -> { try { String jeaseSiteRewriter = Registry.getParameter(Names.JEASE_SITE_REWRITER); return (Function<String, String>) Class.forName(jeaseSiteRewriter).newInstance(); } catch (ReflectiveOperationException e) { e.printStackTrace(); return null; } }; private static String contextPath; private static String dispatcher; private static Pattern servlets; private static Set<String> locales; public static String getContextPath() { return contextPath; } public void init(FilterConfig config) throws ServletException { contextPath = config.getServletContext().getContextPath(); dispatcher = config.getServletContext().getInitParameter(Names.JEASE_SITE_DISPATCHER); servlets = Pattern.compile( String.format("/(%s).*", config.getServletContext().getInitParameter(Names.JEASE_SITE_SERVLETS))); locales = new HashSet<>(); for (Locale locale : Locale.getAvailableLocales()) { locales.add(locale.getLanguage()); } } public void destroy() { } public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain) throws IOException, ServletException { HttpServletRequest request = (HttpServletRequest) servletRequest; HttpServletResponse response = (HttpServletResponse) servletResponse; request.setCharacterEncoding("UTF-8"); response.setCharacterEncoding("UTF-8"); String uri = request.getRequestURI(); // Strip jsessionid from URI. int jsessionidIndex = uri.indexOf(";jsessionid="); if (jsessionidIndex != -1) { uri = uri.substring(0, jsessionidIndex); } // Process internal context prefix int tilde = uri.indexOf("~"); if (tilde != -1) { String path = uri.substring(tilde + 1); response.sendRedirect(response .encodeRedirectURL(buildURI(request.getContextPath() + path, request.getQueryString()))); return; } // Try to resolve node from URI (without context path). String nodePath = uri.substring(request.getContextPath().length()); Node node = Nodes.getByPath(nodePath); // Process redirect rules if (node == null && !servlets.matcher(nodePath).matches()) { String sourceURI = buildURI(nodePath, request.getQueryString()); String targetURI = rewriteURI(sourceURI); if (!targetURI.equals(sourceURI)) { if (targetURI.contains("://")) { response.sendRedirect(response.encodeRedirectURL(targetURI)); } else { response.sendRedirect(response.encodeRedirectURL(request.getContextPath() + targetURI)); } return; } } // Save "virtual" root node. Per default it is the absolute root of the // instance. // If a node with the server name exists, this node is used as virtual // root. if (request.getAttribute("Root") == null) { String server = Servlets.getServerName(request).replaceFirst("www.", ""); Node root = Nodes.getRoot() != null ? Nodes.getRoot().getChild(server) : null; if (root == null) { root = Nodes.getRoot(); } if (node != null) { if (node.getParent() == root && locales.contains(node.getId())) { root = node; } else { for (Node parent : node.getParents()) { if (parent.getParent() == root && locales.contains(parent.getId())) { root = parent; break; } } } } request.setAttribute("Root", root); if (node != null && root.getParent() == node) { response.sendRedirect(response.encodeRedirectURL(request.getContextPath() + root.getPath())); return; } } // If no node is found, process filter chain. if (node == null) { chain.doFilter(request, response); return; } // Redirect if trailing slash is missing for containers. if (node.isContainer() && !uri.endsWith("/")) { response.sendRedirect(response.encodeRedirectURL(buildURI(uri + "/", request.getQueryString()))); } else { // Set node into request scope and forward to dispatcher request.setAttribute(Node.class.getSimpleName(), node); request.setAttribute(Names.JEASE_SITE_DISPATCHER, dispatcher); Function<String, String> rewriter = StringUtils.isNotBlank( Registry.getParameter(Names.JEASE_SITE_REWRITER)) ? Database.query(rewriterSupplier) : null; request.getRequestDispatcher(dispatcher).forward(request, rewriter != null ? new ResponseRewriter(response, rewriter) : response); } } private String buildURI(String uri, String query) { if (query != null) { return String.format("%s%s%s", uri, uri.contains("?") ? "&" : "?", query); } else { return uri; } } private String rewriteURI(String uri) { for (Redirect redirect : Database.query(redirectSupplier)) { String output = redirect.transform(uri); if (!output.equals(uri)) { return output; } } return uri; } }