Java tutorial
/** * \cond LICENSE * ******************************************************************** * This is a conditional block for preventing the DoxyGen documentation * tool to include this license header within the description of each * source code file. If you want to include this block, please define * the LICENSE parameter into the provided DoxyFile. * ******************************************************************** * * TeXPrinter - A TeX.SX question printer * Copyright (c) 2012, Paulo Roberto Massa Cereda * All rights reserved. * * Redistribution and use in source and binary forms, with or * without modification, are permitted provided that the following * conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. Neither the name of the project's author nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * ******************************************************************** * End of the LICENSE conditional block * ******************************************************************** * \endcond * * PDFGenerator.java: This class is responsible for generating a PDF file * from a Question object. * Last revision: paulo at temperantia 26 Feb 2012 14:10 */ // package definition package net.sf.texprinter.generators; // needed imports import com.itextpdf.text.Font.FontFamily; import com.itextpdf.text.*; import com.itextpdf.text.html.simpleparser.ChainedProperties; import com.itextpdf.text.html.simpleparser.HTMLWorker; import com.itextpdf.text.html.simpleparser.ImageProvider; import com.itextpdf.text.html.simpleparser.StyleSheet; import com.itextpdf.text.pdf.PdfWriter; import com.itextpdf.text.pdf.draw.LineSeparator; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.StringReader; import java.net.URL; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.logging.Level; import java.util.logging.Logger; import net.sf.texprinter.model.Comment; import net.sf.texprinter.model.Post; import net.sf.texprinter.model.Question; import net.sf.texprinter.utils.Dialogs; import net.sf.texprinter.utils.ProgressMessage; import net.sf.texprinter.utils.StringUtils; import org.apache.commons.codec.binary.Base64; /** * Provides the PDF generation from a Question object. * * @author Paulo Roberto Massa Cereda * @version 2.1 * @since 1.0 */ public class PDFGenerator { // the application logger private static final Logger log = Logger.getLogger(PDFGenerator.class.getCanonicalName()); /** * Generates a PDF file from a Question object. * * @param question The question. * @param filename The filename. */ public static void generate(Question question, String filename) { // wait window ProgressMessage pm = new ProgressMessage("TeXPrinter is printing your PDF file."); // start wait window //pm.start(); // log message log.log(Level.INFO, "Starting PDF generation of {0}.", filename); // define a new PDF document Document document = null; // define a new PDF writer PdfWriter writer = null; // lets try try { // create a new PDF document document = new Document(); // define a new PDF Writer writer = PdfWriter.getInstance(document, new FileOutputStream(filename)); // set the PDF version writer.setPdfVersion(PdfWriter.VERSION_1_6); // open the document document.open(); // set the title font Font titleFont = new Font(FontFamily.HELVETICA, 16, Font.BOLD, BaseColor.BLACK); // set the chunk for the question title Chunk questionTitle = new Chunk(question.getQuestion().getTitle(), titleFont); // create a paragraph from that chunk Paragraph paragraphQuestionTitle = new Paragraph(questionTitle); // log message log.log(Level.INFO, "Adding the question title."); // add the question title to the document document.add(paragraphQuestionTitle); // set the asker font Font askerFont = new Font(FontFamily.HELVETICA, 10, Font.ITALIC, BaseColor.DARK_GRAY); // set the chunk for the asker Chunk questionAsker = new Chunk("Asked by " + question.getQuestion().getUser().getName() + " (" + question.getQuestion().getUser().getReputation() + ") on " + question.getQuestion().getDate() + " (" + String.valueOf(question.getQuestion().getVotes()) + (question.getQuestion().getVotes() == 1 ? " vote" : " votes") + ")", askerFont); // create a paragraph from that chunk Paragraph paragraphQuestionAsker = new Paragraph(questionAsker); // log message log.log(Level.INFO, "Adding both asker and reputation."); // add the asker to the document document.add(paragraphQuestionAsker); // create a line separator LineSeparator line = new LineSeparator(1, 100, null, Element.ALIGN_CENTER, -5); // add the line to the document document.add(line); // add a new line document.add(Chunk.NEWLINE); // create a list of elements from the question objects List<Element> questionTextObjects = getPostText(question.getQuestion().getText()); // log message log.log(Level.INFO, "Adding the question text."); // for each element for (Element questionTextObject : questionTextObjects) { // add it to the document document.add(questionTextObject); } // add a new line document.add(Chunk.NEWLINE); // create a new font for the comments title Font commentsTitleFont = new Font(FontFamily.HELVETICA, 12, Font.BOLD, BaseColor.BLACK); // create a new chunk based on that font Chunk commentsTitle = new Chunk( "This question has " + question.getQuestion().getComments().size() + ((question.getQuestion().getComments().size() == 1) ? " comment:" : " comments:"), commentsTitleFont); // create a paragraph from that chunk Paragraph paragraphCommentsTitle = new Paragraph(commentsTitle); // if there are comments to this question if (!question.getQuestion().getComments().isEmpty()) { // log message log.log(Level.INFO, "Adding the question comments."); // add that paragraph to the document document.add(paragraphCommentsTitle); // add a new line document.add(Chunk.NEWLINE); // get all the comments List<Comment> questionComments = question.getQuestion().getComments(); // for each comment for (Comment questionComment : questionComments) { // get the elements of the comment text List<Element> questionCommentObjects = getPostText(questionComment.getText()); // for each element for (Element questionCommentObject : questionCommentObjects) { // add it to the document document.add(questionCommentObject); } // create a new paragraph about the comment author Paragraph paragraphCommentAuthor = new Paragraph(questionComment.getAuthor() + " on " + questionComment.getDate() + " (" + String.valueOf(questionComment.getVotes()) + (questionComment.getVotes() == 1 ? " vote" : " votes") + ")", askerFont); // set the alignment to the right paragraphCommentAuthor.setAlignment(Element.ALIGN_RIGHT); // add the paragraph to the document document.add(paragraphCommentAuthor); // add a new line document.add(Chunk.NEWLINE); } } // add a line separator document.add(line); // add two new lines document.add(Chunk.NEWLINE); document.add(Chunk.NEWLINE); // get the list of answers List<Post> answersList = question.getAnswers(); // if there are no answers if (answersList.isEmpty()) { // log message log.log(Level.INFO, "This question has no answers."); // create a new chunk Chunk noAnswersTitle = new Chunk("Sorry, this question has no answers yet.", titleFont); // create a paragraph from that chunk Paragraph paragraphNoAnswersTitle = new Paragraph(noAnswersTitle); // add the paragraph to the document document.add(paragraphNoAnswersTitle); } else { // log message log.log(Level.INFO, "Adding answers."); // there are answers, so create a counter for answers int answerCount = 1; // for each answer for (Post answer : answersList) { // log message log.log(Level.INFO, "Adding answer {0}.", answerCount); // set the message text as empty String answerAccepted = ""; // if the answer is accepted if (answer.isAccepted()) { // add that to the message answerAccepted = " - Marked as accepted."; } // create a new chunk Chunk answerTitle = new Chunk("Answer #" + answerCount, titleFont); // create a paragraph from that chunk Paragraph paragraphAnswerTitle = new Paragraph(answerTitle); // add the paragraph to the document document.add(paragraphAnswerTitle); // increase the counter answerCount++; // create a new chunk Chunk questionAnswerer = new Chunk("Answered by " + answer.getUser().getName() + " (" + answer.getUser().getReputation() + ") on " + answer.getDate() + answerAccepted + " (" + String.valueOf(answer.getVotes()) + (answer.getVotes() == 1 ? " vote" : " votes") + ")", askerFont); // create a paragraph from that chunk Paragraph paragraphQuestionAnswerer = new Paragraph(questionAnswerer); // add that paragraph to the document document.add(paragraphQuestionAnswerer); // add a line separator document.add(line); // add a new line document.add(Chunk.NEWLINE); // create a list of elements from the answer text List<Element> answerTextObjects = getPostText(answer.getText()); // for each element for (Element answerTextObject : answerTextObjects) { // add it to the document document.add(answerTextObject); } // add a new line document.add(Chunk.NEWLINE); // create a new font style Font answerCommentsTitleFont = new Font(FontFamily.HELVETICA, 12, Font.BOLD, BaseColor.BLACK); // create a new chunk Chunk answerCommentsTitle = new Chunk( "This answer has " + answer.getComments().size() + ((answer.getComments().size() == 1) ? " comment:" : " comments:"), answerCommentsTitleFont); // create a paragraph from that chunk Paragraph paragraphAnswerCommentsTitle = new Paragraph(answerCommentsTitle); // if there are comments for that answer if (!answer.getComments().isEmpty()) { // log message log.log(Level.INFO, "Adding comments for answer {0}.", (answerCount - 1)); // add that paragraph to the document document.add(paragraphAnswerCommentsTitle); // add a new line document.add(Chunk.NEWLINE); // get all the comments List<Comment> answerComments = answer.getComments(); // for each comment for (Comment answerComment : answerComments) { // create a list of elements from the comment text List<Element> answerCommentObjects = getPostText(answerComment.getText()); // for each element for (Element answerCommentObject : answerCommentObjects) { // add it to the document document.add(answerCommentObject); } // create a new paragraph for the comment author Paragraph paragraphAnswerCommentAuthor = new Paragraph( answerComment.getAuthor() + " on " + answerComment.getDate() + " (" + String.valueOf(answerComment.getVotes()) + (answerComment.getVotes() == 1 ? " vote" : " votes") + ")", askerFont); // set the aligment to the right paragraphAnswerCommentAuthor.setAlignment(Element.ALIGN_RIGHT); // add the paragraph to the document document.add(paragraphAnswerCommentAuthor); // add a new line document.add(Chunk.NEWLINE); } } // add a line separator document.add(line); // add two new lines document.add(Chunk.NEWLINE); document.add(Chunk.NEWLINE); } } // log message log.log(Level.INFO, "PDF generation complete, closing {0}.", filename); // close the document document.close(); // stop wait window pm.interrupt(); } catch (IOException ioexception) { // stop wait window pm.interrupt(); // log message log.log(Level.SEVERE, "An IO error occurred while trying to create the PDF file. MESSAGE: {0}", StringUtils.printStackTrace(ioexception)); // critical error, exit Dialogs.showExceptionWindow(); } catch (Exception exception) { // log message log.log(Level.SEVERE, "A generic error occurred while trying to create the PDF file. MESSAGE: {0}", StringUtils.printStackTrace(exception)); // log message log.log(Level.INFO, "I will try to remove the remaining PDF file."); try { // log message log.log(Level.INFO, "Closing both document and writer."); // close the document document.close(); // close the writer writer.close(); } catch (Exception ex) { // log message log.log(Level.WARNING, "I could not close either document or writer. MESSAGE: {0}", StringUtils.printStackTrace(ex)); } try { // reference problematic file File target = new File(filename); // log message log.log(Level.INFO, "Opening problematic file {0}.", filename); // check if file exists if (target.exists()) { // log message log.log(Level.INFO, "File exists, trying to delete it."); // trying to remove it if (target.delete()) { // log message log.log(Level.INFO, "File {0} was successfully removed.", filename); } else { // log message log.log(Level.SEVERE, "File {0} could not be removed.", filename); } } } catch (SecurityException se) { // log message log.log(Level.SEVERE, "A security exception was raised. MESSAGE: {0}", StringUtils.printStackTrace(se)); } // stop wait window pm.interrupt(); // critical error, exit Dialogs.showExceptionWindow(); } } /** * Parses the HTML text to a list of elements. * * @param text The text. * @return A list of elements. * @throws IOException Throws an IOException if the StringReader couldn't * get the string provided. */ private static List<Element> getPostText(String text) throws IOException { // set the text to a snippet String snippet = text; // full code tag is not supported snippet = snippet.replaceAll("<pre><code>", "<pre>"); snippet = snippet.replaceAll("<pre class=.*\"><code>", "<pre>"); snippet = snippet.replaceAll("</code></pre>", "</pre>"); // code tag is not supported snippet = snippet.replaceAll("<code>", "<font face=\"Courier\">"); snippet = snippet.replaceAll("</code>", "</font>"); // add new lines snippet = snippet.replaceAll("\n", "<br/>"); // create a new stylesheet StyleSheet styles = new StyleSheet(); // configure lists styles.loadTagStyle("ul", "indent", "10"); styles.loadTagStyle("li", "leading", "14"); // configure hyperlinks styles.loadTagStyle("a", "color", "blue"); // create a map of providers HashMap providers = new HashMap(); // set the image provider providers.put("img_provider", new TeXImageFactory()); // parse the HTML to a list List<Element> objects = HTMLWorker.parseToList(new StringReader(snippet), styles, providers); // return the new list return objects; } /** * Image factory implementation. */ public static class TeXImageFactory implements ImageProvider { /** * Gets the image. * * @param string the image URL. * @param map A map. * @param cprops The properties. * @param doc The document listener. * @return An image. */ @Override public Image getImage(String string, Map<String, String> map, ChainedProperties cprops, DocListener doc) { // log message log.log(Level.INFO, "Trying to get current image."); // define the image Image img = null; // lets try try { // create a new URL URL image = new URL(string); // get the image img = Image.getInstance(image); // if the image width is too big if (img.getWidth() > 500) { // scale the image img.scalePercent(50); } } catch (Exception except) { // image had a problem // log message log.log(Level.WARNING, "An error occurred while getting the current image. Trying to set the replacement image instead. MESSAGE: {0}", StringUtils.printStackTrace(except)); // lets try try { // create a new image img = Image.getInstance((new Base64()).decode( "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")); } catch (Exception exception) { // log message log.log(Level.SEVERE, "An error occured while trying to create the image replacement. MESSAGE: {0}", StringUtils.printStackTrace(exception)); } } // log message log.log(Level.INFO, "Image retrieved succesfully."); // return image return img; } } }