org.getobjects.samples.HelloPDF.PDFAction.java Source code

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Here is the source code for org.getobjects.samples.HelloPDF.PDFAction.java

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/*
  Copyright (C) 2007 Helge Hess
    
  This file is part of Go.
    
  Go is free software; you can redistribute it and/or modify it under
  the terms of the GNU Lesser General Public License as published by the
  Free Software Foundation; either version 2, or (at your option) any
  later version.
    
  Go 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 Lesser General Public
  License for more details.
    
  You should have received a copy of the GNU Lesser General Public
  License along with Go; see the file COPYING.  If not, write to the
  Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.
*/
package org.getobjects.samples.HelloPDF;

import java.io.ByteArrayOutputStream;

import org.getobjects.appserver.core.WOContext;
import org.getobjects.appserver.core.WODirectAction;
import org.getobjects.appserver.core.WOResponse;

import com.lowagie.text.Document;
import com.lowagie.text.DocumentException;
import com.lowagie.text.Element;
import com.lowagie.text.Paragraph;
import com.lowagie.text.pdf.PdfPCell;
import com.lowagie.text.pdf.PdfPTable;
import com.lowagie.text.pdf.PdfWriter;

/**
 * A WODirectAction object is pretty much like a servlet, it can accept
 * requests and is responsible for producing a result. The result can be
 * either a WOResponse or a WOComponent or anything else which can be
 * rendered by Go.
 * <p>
 * In this example we directly generate a WOResponse with the
 * application/pdf content type.
 * 
 * @author helge
 */
public class PDFAction extends WODirectAction {

    public PDFAction(WOContext _ctx) {
        super(_ctx);
    }

    /**
     * Add some content to the PDF. This is using iText methods to add some text
     * and a few tables to the given Document.
     * Note how you can reuse higher-level objects once they got added to the
     * document (iText does not keep a higher level structure but directly
     * generates the PDF content).
     * 
     * @param _itext - the iText Document object
     * @throws DocumentException
     */
    void addContent(Document _itext) throws DocumentException {

        /* a small paragraph */

        _itext.add(new Paragraph("Hello World"));

        /* a simple table (default width is 80%) */

        PdfPTable table = new PdfPTable(3);
        table.setSpacingBefore(10);
        table.setSpacingAfter(10);

        PdfPCell th = new PdfPCell(new Paragraph("Title"));
        th.setColspan(3);
        table.addCell(th);

        for (int i = 0; i < 8; i++) {
            for (int j = 0; j < 3; j++)
                table.addCell("" + i + "/" + j);
        }

        _itext.add(table);

        /* readd table with full width */

        table.setWidthPercentage(100);
        _itext.add(table);

        /* readd with align */

        table.setWidthPercentage(60);
        table.setHorizontalAlignment(Element.ALIGN_LEFT);
        _itext.add(table);

        /* and make a big table to enforce a pagebreak */

        for (int i = 0; i < 32; i++) {
            for (int j = 0; j < 3; j++)
                table.addCell("" + i + "/" + j);
        }
        _itext.add(table);
    }

    /**
     * This method is called when you invoke the direct action like this:<pre>
     *   /HelloPDF/wa/PDFAction/default</pre>
     *   
     * @return returns the WOResponse with the PDF or an Exception
     */
    @Override
    public Object defaultAction() {

        /* The book says browsers do not deal well with missing content-lengths,
         * so we can't stream the PDF directly.
         * Technically it would probably be best to stream to a file and then
         * deliver that on the socket using sendfile().
         */
        ByteArrayOutputStream bas = new ByteArrayOutputStream(16000);

        /* generate PDF */

        Document itDoc = new Document();
        try {
            PdfWriter.getInstance(itDoc, bas);
        } catch (DocumentException e) {
            daLog.error("got no PdfWriter instance?", e);
            return e;
        }

        itDoc.open();

        try {
            this.addContent(itDoc);
        } catch (DocumentException e) {
            daLog.error("failed to add PDF paragraph", e);
            return e;
        }

        itDoc.close();

        /* generate response */

        WOResponse r = this.context().response();

        r.setHeaderForKey("application/pdf", "content-type");
        r.setHeaderForKey("inline; filename=test.pdf", "content-disposition");
        r.setContent(bas.toByteArray());
        r.setHeaderForKey("" + bas.size(), "content-length");

        return r;
    }

}