PAGENUMBER

最新推荐文章于 2022-07-18 00:06:58 发布
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#import #initialization #exception #templates #image #string
本文介绍了一个使用iText库创建PDF文档的例子，演示如何在PDF文件中添加每页的水印和页码。通过模板和事件监听器，实现自定义页眉、页脚以及透明度可调的水印。
/*
 * $Id: PageNumbersWatermark.java,v 1.3 2005/05/09 11:52:50 blowagie Exp $
 * $Name:  $
 *
 * This code is part of the 'iText Tutorial'.
 * You can find the complete tutorial at the following address:
 * http://itextdocs.lowagie.com/tutorial/
 *
 * This code 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.
 *
 * itext-questions@lists.sourceforge.net
 */
package com.lowagie.examples.directcontent.pageevents;

import java.awt.Color;
import java.io.FileOutputStream;

import com.lowagie.text.Chunk;
import com.lowagie.text.Document;
import com.lowagie.text.Element;
import com.lowagie.text.ExceptionConverter;
import com.lowagie.text.Font;
import com.lowagie.text.Image;
import com.lowagie.text.PageSize;
import com.lowagie.text.Paragraph;
import com.lowagie.text.Phrase;
import com.lowagie.text.Rectangle;
import com.lowagie.text.pdf.BaseFont;
import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfGState;
import com.lowagie.text.pdf.PdfPTable;
import com.lowagie.text.pdf.PdfPageEventHelper;
import com.lowagie.text.pdf.PdfTemplate;
import com.lowagie.text.pdf.PdfWriter;
/**
 * Demonstrates the use of templates to add Watermarks and Pagenumbers.
 */
public class PageNumbersWatermark extends PdfPageEventHelper {
	/** An Image that goes in the header. */
    public Image headerImage;
    /** The headertable. */
    public PdfPTable table;
    /** The Graphic state */
    public PdfGState gstate;
    /** A template that will hold the total number of pages. */
    public PdfTemplate tpl;
    /** The font that will be used. */
    public BaseFont helv;
    
    /**
     * Generates a document with a header containing Page x of y and with a Watermark on every page.
     * @param args no arguments needed
     */
    public static void main(String args[]) {
        try {
        	// step 1: creating the document
            Document doc = new Document(PageSize.A4, 50, 50, 100, 72);
            // step 2: creating the writer
            PdfWriter writer = PdfWriter.getInstance(doc, new FileOutputStream("pageNumbersWatermark.pdf"));
            // step 3: initialisations + opening the document
            writer.setPageEvent(new PageNumbersWatermark());
            doc.open();
            // step 4: adding content
            String text = "some padding text ";
            for (int k = 0; k < 10; ++k)
                text += text;
            Paragraph p = new Paragraph(text);
            p.setAlignment(Element.ALIGN_JUSTIFIED);
            doc.add(p);
            // step 5: closing the document
            doc.close();
        }
        catch ( Exception e ) {
            e.printStackTrace();
        }
    }
    
    /**
     * @see com.lowagie.text.pdf.PdfPageEventHelper#onOpenDocument(com.lowagie.text.pdf.PdfWriter, com.lowagie.text.Document)
     */
    public void onOpenDocument(PdfWriter writer, Document document) {
        try {
        	// initialization of the header table
            headerImage = Image.getInstance("logo.gif");
            table = new PdfPTable(2);
            Phrase p = new Phrase();
            Chunk ck = new Chunk("lowagie.com/n", new Font(Font.TIMES_ROMAN, 16, Font.BOLDITALIC, Color.blue));
            p.add(ck);
            ck = new Chunk("Ghent/nBelgium", new Font(Font.HELVETICA, 12, Font.NORMAL, Color.darkGray));
            p.add(ck);
            table.getDefaultCell().setBackgroundColor(Color.yellow);
            table.getDefaultCell().setBorderWidth(0);
            table.addCell(p);
            table.getDefaultCell().setHorizontalAlignment(Element.ALIGN_RIGHT);
            table.addCell(new Phrase(new Chunk(headerImage, 0, 0)));
            // initialization of the Graphic State
            gstate = new PdfGState();
            gstate.setFillOpacity(0.3f);
            gstate.setStrokeOpacity(0.3f);
            // initialization of the template
            tpl = writer.getDirectContent().createTemplate(100, 100);
            tpl.setBoundingBox(new Rectangle(-20, -20, 100, 100));
            // initialization of the font
            helv = BaseFont.createFont("Helvetica", BaseFont.WINANSI, false);
        }
        catch(Exception e) {
            throw new ExceptionConverter(e);
        }
    }    
    
    /**
     * @see com.lowagie.text.pdf.PdfPageEventHelper#onEndPage(com.lowagie.text.pdf.PdfWriter, com.lowagie.text.Document)
     */
    public void onEndPage(PdfWriter writer, Document document) {
        PdfContentByte cb = writer.getDirectContent();
        cb.saveState();
        // write the headertable
        table.setTotalWidth(document.right() - document.left());
        table.writeSelectedRows(0, -1, document.left(), document.getPageSize().height() - 50, cb);
        // compose the footer
        String text = "Page " + writer.getPageNumber() + " of ";
        float textSize = helv.getWidthPoint(text, 12);
        float textBase = document.bottom() - 20;
        cb.beginText();
        cb.setFontAndSize(helv, 12);
        // for odd pagenumbers, show the footer at the left
        if ((writer.getPageNumber() & 1) == 1) {
            cb.setTextMatrix(document.left(), textBase);
            cb.showText(text);
            cb.endText();
            cb.addTemplate(tpl, document.left() + textSize, textBase);
        }
        // for even numbers, show the footer at the right
        else {
            float adjust = helv.getWidthPoint("0", 12);
            cb.setTextMatrix(document.right() - textSize - adjust, textBase);
            cb.showText(text);
            cb.endText();
            cb.addTemplate(tpl, document.right() - adjust, textBase);
        }
        cb.saveState();
        // draw a Rectangle around the page
        cb.setColorStroke(Color.orange);
        cb.setLineWidth(2);
        cb.rectangle(20, 20, document.getPageSize().width() - 40, document.getPageSize().height() - 40);
        cb.stroke();
        cb.restoreState();
        // starting on page 3, a watermark with an Image that is made transparent
        if (writer.getPageNumber() >= 3) {
            cb.setGState(gstate);
            cb.setColorFill(Color.red);
            cb.beginText();
            cb.setFontAndSize(helv, 48);
            cb.showTextAligned(Element.ALIGN_CENTER, "Watermark Opacity " + writer.getPageNumber(), document.getPageSize().width() / 2, document.getPageSize().height() / 2, 45);
            cb.endText();
            try {
                cb.addImage(headerImage, headerImage.width(), 0, 0, headerImage.height(), 440, 80);
            }
            catch(Exception e) {
                throw new ExceptionConverter(e);
            }
            cb.restoreState();
        }
    }
    
    /**
     * @see com.lowagie.text.pdf.PdfPageEventHelper#onStartPage(com.lowagie.text.pdf.PdfWriter, com.lowagie.text.Document)
     */
    public void onStartPage(PdfWriter writer, Document document) {
        if (writer.getPageNumber() < 3) {
            PdfContentByte cb = writer.getDirectContentUnder();
            cb.saveState();
            cb.setColorFill(Color.pink);
            cb.beginText();
            cb.setFontAndSize(helv, 48);
            cb.showTextAligned(Element.ALIGN_CENTER, "My Watermark Under " + writer.getPageNumber(), document.getPageSize().width() / 2, document.getPageSize().height() / 2, 45);
            cb.endText();
            cb.restoreState();
        }
    }
    
    /**
     * @see com.lowagie.text.pdf.PdfPageEventHelper#onCloseDocument(com.lowagie.text.pdf.PdfWriter, com.lowagie.text.Document)
     */
    public void onCloseDocument(PdfWriter writer, Document document) {
       tpl.beginText();
       tpl.setFontAndSize(helv, 12);
       tpl.setTextMatrix(0, 0);
       tpl.showText("" + (writer.getPageNumber() - 1));
       tpl.endText();
    }
}