Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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.apache.jackrabbit.demo.blog.servlet; import java.io.IOException; import java.util.Calendar; import java.util.Iterator; import java.util.List; import javax.jcr.LoginException; import javax.jcr.Node; import javax.jcr.RepositoryException; import javax.jcr.Session; import javax.jcr.SimpleCredentials; import javax.jcr.Value; import javax.servlet.RequestDispatcher; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.DefaultFileItemFactory; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.servlet.ServletFileUpload; /** * This servlet is the controller for adding blog entries. A Title and a text content is passed * with the request as request parameters. Optionally an image attachment and/or a video * attachment also can be present as request parameters. Requests to this servlet must be multi-part * encoded. */ public class BlogAddControllerServlet extends ControllerServlet { /** * Serial version UID. */ private static final long serialVersionUID = -2175972214551818679L; /** * This methods handles POST requests and adds the blog entries according to the parameters in the * request. Request must be multi-part encoded. */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { List parameters = null; String title = null; String content = null; FileItem image = null; FileItem video = null; // Check whether the request is multipart encoded if (ServletFileUpload.isMultipartContent(request)) { DefaultFileItemFactory fileItemFactory = new DefaultFileItemFactory(); ServletFileUpload fileUpload = new ServletFileUpload(fileItemFactory); try { // Parse the request and get the paramter set parameters = fileUpload.parseRequest(request); Iterator paramIter = parameters.iterator(); // Resolve the parameter set while (paramIter.hasNext()) { FileItem item = (FileItem) paramIter.next(); if (item.getFieldName().equalsIgnoreCase("title")) { title = item.getString(); } else if (item.getFieldName().equalsIgnoreCase("content")) { content = item.getString(); } else if (item.getFieldName().equalsIgnoreCase("image")) { image = item; } else if (item.getFieldName().equalsIgnoreCase("video")) { video = item; } } } catch (FileUploadException e) { throw new ServletException("Error occured in processing the multipart request", e); } } else { throw new ServletException("Request is not a multi-part encoded request"); } try { //log in to the repository and aquire a session Session session = repository.login(new SimpleCredentials("username", "password".toCharArray())); String username = (String) request.getSession().getAttribute("username"); // Only logged in users are allowed to create blog entries if (username == null) { //set the attributes which are required by user messae page request.setAttribute("msgTitle", "Authentication Required"); request.setAttribute("msgBody", "Only logged in users are allowed to add blog entries."); request.setAttribute("urlText", "go back to login page"); request.setAttribute("url", "/jackrabbit-jcr-demo/blog/index.jsp"); //forward the request to user massage page RequestDispatcher requestDispatcher = this.getServletContext() .getRequestDispatcher("/blog/userMessage.jsp"); requestDispatcher.forward(request, response); return; } Node blogRootNode = session.getRootNode().getNode("blogRoot"); Node userNode = blogRootNode.getNode(username); // Node to hold the current year Node yearNode; // Node to hold the current month Node monthNode; // Node to hold the blog entry to be added Node blogEntryNode; // Holds the name of the blog entry node String nodeName; // createdOn property of the blog entry is set to the current time. Calendar calendar = Calendar.getInstance(); String year = calendar.get(Calendar.YEAR) + ""; String month = calendar.get(Calendar.MONTH) + ""; // check whether node exists for current year under usernode and creates a one if not exist if (userNode.hasNode(year)) { yearNode = userNode.getNode(year); } else { yearNode = userNode.addNode(year, "nt:folder"); } // check whether node exists for current month under the current year and creates a one if not exist if (yearNode.hasNode(month)) { monthNode = yearNode.getNode(month); } else { monthNode = yearNode.addNode(month, "nt:folder"); } if (monthNode.hasNode(title)) { nodeName = createUniqueName(title, monthNode); } else { nodeName = title; } // creates a blog entry under the current month blogEntryNode = monthNode.addNode(nodeName, "blog:blogEntry"); blogEntryNode.setProperty("blog:title", title); blogEntryNode.setProperty("blog:content", content); Value date = session.getValueFactory().createValue(Calendar.getInstance()); blogEntryNode.setProperty("blog:created", date); blogEntryNode.setProperty("blog:rate", 0); // If the blog entry has an image if (image.getSize() > 0) { if (image.getContentType().startsWith("image")) { Node imageNode = blogEntryNode.addNode("image", "nt:file"); Node contentNode = imageNode.addNode("jcr:content", "nt:resource"); contentNode.setProperty("jcr:data", image.getInputStream()); contentNode.setProperty("jcr:mimeType", image.getContentType()); contentNode.setProperty("jcr:lastModified", date); } else { session.refresh(false); //set the attributes which are required by user messae page request.setAttribute("msgTitle", "Unsupported image format"); request.setAttribute("msgBody", "The image you attached in not supported"); request.setAttribute("urlText", "go back to new blog entry page"); request.setAttribute("url", "/jackrabbit-jcr-demo/blog/addBlogEntry.jsp"); //forward the request to user massage page RequestDispatcher requestDispatcher = this.getServletContext() .getRequestDispatcher("/blog/userMessage.jsp"); requestDispatcher.forward(request, response); return; } } // If the blog entry has a video if (video.getSize() > 0) { if (video.getName().endsWith(".flv") || video.getName().endsWith(".FLV")) { Node imageNode = blogEntryNode.addNode("video", "nt:file"); Node contentNode = imageNode.addNode("jcr:content", "nt:resource"); contentNode.setProperty("jcr:data", video.getInputStream()); contentNode.setProperty("jcr:mimeType", video.getContentType()); contentNode.setProperty("jcr:lastModified", date); } else { session.refresh(false); //set the attributes which are required by user messae page request.setAttribute("msgTitle", "Unsupported video format"); request.setAttribute("msgBody", "Only Flash videos (.flv) are allowed as video attachement. click <a href=\"www.google.com\">here</a> to covert the videos online."); request.setAttribute("urlText", "go back to new blog entry page"); request.setAttribute("url", "/jackrabbit-jcr-demo/blog/addBlogEntry.jsp"); //forward the request to user massage page RequestDispatcher requestDispatcher = this.getServletContext() .getRequestDispatcher("/blog/userMessage.jsp"); requestDispatcher.forward(request, response); return; } } // persist the changes done session.save(); //set the attributes which are required by user messae page request.setAttribute("msgTitle", "Blog entry added succesfully"); request.setAttribute("msgBody", "Blog entry titled \"" + title + "\" was successfully added to your blog space"); request.setAttribute("urlText", "go back to my blog page"); request.setAttribute("url", "/jackrabbit-jcr-demo/blog/view"); //forward the request to user massage page RequestDispatcher requestDispatcher = this.getServletContext() .getRequestDispatcher("/blog/userMessage.jsp"); requestDispatcher.forward(request, response); } catch (RepositoryException e) { throw new ServletException("Repository error occured", e); } finally { if (session != null) { session.logout(); } } } /** * Method that creates a unique title when the given title already exists in the parent node * Parent node is the node for the current month */ private String createUniqueName(String name, Node node) throws RepositoryException { String unique; int i = 0; do { unique = name + (i++); } while (node.hasNode(unique)); return unique; } }