iText实战--Table、cell 和 page event

5.1 使用表和单元格事件装饰表

实现PdfPTableEvent 接口

实现PdfPCellEvent 接口

合并表格和单元格事件

5.2 基本构建块的事件

通用块（Chunk）功能

段落（Paragraph）事件

章节（Chapter）和 区域（Section）事件

页面顺序和空白页面

5.3 页面边界概述

媒体盒

作物箱

其他页面边界

5.4 添加页码事件到 PdfWriter

PdfPageEvent 接口

onOpenDocument()：当文档打开后触发，初始化变量整个文档可使用

onStartPage()：当开始一个新页面触发，初始化页面级变量，不要在这个方法内添加内容

onEndPage()：开始一个新页面并在文档关闭前触发，这里添加header、footer、watermark等

onCloseDocument()：文档关闭时触发，这里释放资源

添加页头与页尾

import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.SQLException;
import com.itextpdf.text.Chapter;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.Font.FontFamily;
import com.itextpdf.text.pdf.ColumnText;
import com.itextpdf.text.pdf.PdfPageEventHelper;
import com.itextpdf.text.pdf.PdfWriter;public class MovieHistory2 {/** The resulting PDF file. */public static final String RESULT= "results/part1/chapter05/movie_history2.pdf";/** Inner class to add a header and a footer. */class HeaderFooter extends PdfPageEventHelper {/** Alternating phrase for the header. */Phrase[] header = new Phrase[2];/** Current page number (will be reset for every chapter). */int pagenumber;/*** Initialize one of the headers.* @see com.itextpdf.text.pdf.PdfPageEventHelper#onOpenDocument(*      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)*/public void onOpenDocument(PdfWriter writer, Document document) {header[0] = new Phrase("Movie history");}/*** Initialize one of the headers, based on the chapter title;* reset the page number.* @see com.itextpdf.text.pdf.PdfPageEventHelper#onChapter(*      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document, float,*      com.itextpdf.text.Paragraph)*/public void onChapter(PdfWriter writer, Document document,float paragraphPosition, Paragraph title) {header[1] = new Phrase(title.getContent());pagenumber = 1;}/*** Increase the page number.* @see com.itextpdf.text.pdf.PdfPageEventHelper#onStartPage(*      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)*/public void onStartPage(PdfWriter writer, Document document) {pagenumber++;}/*** Adds the header and the footer.* @see com.itextpdf.text.pdf.PdfPageEventHelper#onEndPage(*      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)*/public void onEndPage(PdfWriter writer, Document document) {Rectangle rect = writer.getBoxSize("art");switch(writer.getPageNumber() % 2) {case 0:ColumnText.showTextAligned(writer.getDirectContent(),Element.ALIGN_RIGHT, header[0],rect.getRight(), rect.getTop(), 0);break;case 1:ColumnText.showTextAligned(writer.getDirectContent(),Element.ALIGN_LEFT, header[1],rect.getLeft(), rect.getTop(), 0);break;}ColumnText.showTextAligned(writer.getDirectContent(),Element.ALIGN_CENTER, new Phrase(String.format("page %d", pagenumber)),(rect.getLeft() + rect.getRight()) / 2, rect.getBottom() - 18, 0);}}/** The different epochs. */public static final String[] EPOCH ={ "Forties", "Fifties", "Sixties", "Seventies", "Eighties","Nineties", "Twenty-first Century" };/** The fonts for the title. */public static final Font[] FONT = new Font[4];static {FONT[0] = new Font(FontFamily.HELVETICA, 24);FONT[1] = new Font(FontFamily.HELVETICA, 18);FONT[2] = new Font(FontFamily.HELVETICA, 14);FONT[3] = new Font(FontFamily.HELVETICA, 12, Font.BOLD);}/*** Creates a PDF document.* @param filename the path to the new PDF document* @throws    DocumentException * @throws    IOException* @throws    SQLException*/public void createPdf(String filename)throws IOException, DocumentException, SQLException {// step 1Document document = new Document(PageSize.A4, 36, 36, 54, 54);// step 2PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(RESULT));HeaderFooter event = new HeaderFooter();writer.setBoxSize("art", new Rectangle(36, 54, 559, 788));writer.setPageEvent(event);// step 3document.open();// step 4Chapter chapter = null;// 初始化数据...document.add(chapter);// step 5document.close();}/*** Main method.** @param    args    no arguments needed* @throws DocumentException * @throws IOException * @throws SQLException*/public static void main(String[] args)throws IOException, DocumentException, SQLException {new MovieHistory2().createPdf(RESULT);}
}

解决 page X of Y 问题

利用XObject特性，iText 真正将PdfTemplate 写入 OutputStream 是在调用releaseTemplate() 时。

import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.SQLException;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.ExceptionConverter;
import com.itextpdf.text.Image;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.ColumnText;
import com.itextpdf.text.pdf.PdfPCell;
import com.itextpdf.text.pdf.PdfPTable;
import com.itextpdf.text.pdf.PdfPageEventHelper;
import com.itextpdf.text.pdf.PdfTemplate;
import com.itextpdf.text.pdf.PdfWriter;public class MovieCountries1 {/** The resulting PDF file. */public static final String RESULT= "D:/data/iText/inAction/chapter05/movie_countries1.pdf";/*** Inner class to add a table as header.*/class TableHeader extends PdfPageEventHelper {/** The header text. */String header;/** The template with the total number of pages. */PdfTemplate total;/*** Allows us to change the content of the header.* @param header The new header String*/public void setHeader(String header) {this.header = header;}/*** Creates the PdfTemplate that will hold the total number of pages.* @see com.itextpdf.text.pdf.PdfPageEventHelper#onOpenDocument(*      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)*/public void onOpenDocument(PdfWriter writer, Document document) {total = writer.getDirectContent().createTemplate(30, 16);}/*** Adds a header to every page* @see com.itextpdf.text.pdf.PdfPageEventHelper#onEndPage(*      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)*/public void onEndPage(PdfWriter writer, Document document) {PdfPTable table = new PdfPTable(3);try {table.setWidths(new int[]{24, 24, 2});table.setTotalWidth(527);table.setLockedWidth(true);table.getDefaultCell().setFixedHeight(20);table.getDefaultCell().setBorder(Rectangle.BOTTOM);table.addCell(header);table.getDefaultCell().setHorizontalAlignment(Element.ALIGN_RIGHT);table.addCell(String.format("Page %d of", writer.getPageNumber()));PdfPCell cell = new PdfPCell(Image.getInstance(total));cell.setBorder(Rectangle.BOTTOM);table.addCell(cell);table.writeSelectedRows(0, -1, 34, 803, writer.getDirectContent());}catch(DocumentException de) {throw new ExceptionConverter(de);}}/*** Fills out the total number of pages before the document is closed.* @see com.itextpdf.text.pdf.PdfPageEventHelper#onCloseDocument(*      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)*/public void onCloseDocument(PdfWriter writer, Document document) {ColumnText.showTextAligned(total, Element.ALIGN_LEFT,new Phrase(String.valueOf(writer.getPageNumber() - 1)),2, 2, 0);}}/*** Creates a PDF document.* @param filename the path to the new PDF document* @throws    DocumentException * @throws    IOException* @throws    SQLException*/public void createPdf(String filename)throws IOException, DocumentException, SQLException {// step 1Document document = new Document(PageSize.A4, 36, 36, 54, 36);// step 2PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(RESULT));TableHeader event = new TableHeader();writer.setPageEvent(event);// step 3document.open();// step 4// 新建页面数据...document.add(new Phrase("Hello Page 1."));document.newPage();document.add(new Phrase("Hello Page 2."));document.newPage();document.add(new Phrase("Hello Page 3."));document.newPage();document.add(new Phrase("Hello Page 4."));// step 4document.close();}/*** Main method.** @param    args    no arguments needed* @throws DocumentException * @throws IOException * @throws SQLException*/public static void main(String[] args)throws IOException, DocumentException, SQLException {new MovieCountries1().createPdf(RESULT);}
}

在页尾添加页码

import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.SQLException;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.ExceptionConverter;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfPageEventHelper;
import com.itextpdf.text.pdf.PdfTemplate;
import com.itextpdf.text.pdf.PdfWriter;/*** TODO 在此写上类的相关说明.<br>* @author gongqiang <br>* @version 1.0.0 2023年9月18日<br>* @see * @since JDK 1.5.0*/
public class MovieCountries {/** The resulting PDF file. */public static final String RESULT= "D:/data/iText/inAction/chapter05/movie_countries.pdf";/*** Inner class to add a table as header.*/class TableHeader extends PdfPageEventHelper {/** The header text. */String header;/** The template with the total number of pages. */PdfTemplate total;BaseFont baseFont;int fontSize = 14;/*** Allows us to change the content of the header.* @param header The new header String*/public void setHeader(String header) {this.header = header;}/*** Creates the PdfTemplate that will hold the total number of pages.* @see com.itextpdf.text.pdf.PdfPageEventHelper#onOpenDocument(*      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)*/public void onOpenDocument(PdfWriter writer, Document document) {total = writer.getDirectContent().createTemplate(30, 16);try {baseFont = BaseFont.createFont("D:/data/iText/fonts/simfang.ttf", BaseFont.IDENTITY_H, BaseFont.NOT_EMBEDDED);} catch (Exception e) {throw new ExceptionConverter(e);}}/*** Adds a header to every page* @see com.itextpdf.text.pdf.PdfPageEventHelper#onEndPage(*      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)*/public void onEndPage(PdfWriter writer, Document document) {// 新建获得用户页面文本和图片内容位置的对象PdfContentByte pdfContentByte = writer.getDirectContent();// 保存图形状态pdfContentByte.saveState();String text = "页" + writer.getPageNumber() + "/";//String text = "页 99/";// 获取点字符串的宽度float textSize = baseFont.getWidthPoint(text, fontSize);pdfContentByte.beginText();// 设置随后的文本内容写作的字体和字号pdfContentByte.setFontAndSize(baseFont, fontSize);// 定位'X/'
//            float x = (document.right() + document.left()) / 2;float x = document.right() - 50;float y = 20f;pdfContentByte.setTextMatrix(x, y);pdfContentByte.showText(text);pdfContentByte.endText();// 将模板加入到内容（content）中- // 定位'Y'pdfContentByte.addTemplate(total, x + textSize, y);pdfContentByte.restoreState();}/*** Fills out the total number of pages before the document is closed.* @see com.itextpdf.text.pdf.PdfPageEventHelper#onCloseDocument(*      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)*/public void onCloseDocument(PdfWriter writer, Document document) {total.beginText();total.setFontAndSize(baseFont, fontSize);total.setTextMatrix(0, 0);// 设置总页数的值到模板上，并应用到每个界面total.showText(String.valueOf(writer.getPageNumber()));//total.showText(String.valueOf("99"));total.endText();}}/*** Creates a PDF document.* @param filename the path to the new PDF document* @throws    DocumentException * @throws    IOException* @throws    SQLException*/public void createPdf(String filename)throws IOException, DocumentException, SQLException {// step 1Document document = new Document(PageSize.A4, 36, 36, 54, 36);// step 2PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(RESULT));TableHeader event = new TableHeader();writer.setPageEvent(event);// step 3document.open();// step 4// 新建页面数据...document.add(new Phrase("Hello Page 1."));document.newPage();document.add(new Phrase("Hello Page 2."));document.newPage();document.add(new Phrase("Hello Page 3."));document.newPage();document.add(new Phrase("Hello Page 4."));// step 4document.close();}/*** Main method.** @param    args    no arguments needed* @throws DocumentException * @throws IOException * @throws SQLException*/public static void main(String[] args)throws IOException, DocumentException, SQLException {new MovieCountries().createPdf(RESULT);}
}

添加水印

如果水印是图片，可以通过PdfContentByte.addImage()、或将图片包装成ColumnText对象，或者添加到表格的cell里。

注意：Image对象需要在onOpenDocument()方法内初始化，避免重复添加图片的字节流。

import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.SQLException;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.Font.FontFamily;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.pdf.ColumnText;
import com.itextpdf.text.pdf.GrayColor;
import com.itextpdf.text.pdf.PdfPageEventHelper;
import com.itextpdf.text.pdf.PdfWriter;public class MovieCountries2 extends MovieCountries1 {/** The resulting PDF file. */public static final String RESULT= "D:/data/iText/inAction/chapter05/movie_countries2.pdf";/*** Inner class to add a watermark to every page.*/class Watermark extends PdfPageEventHelper {Font FONT = new Font(FontFamily.HELVETICA, 52, Font.BOLD, new GrayColor(0.75f));public void onEndPage(PdfWriter writer, Document document) {ColumnText.showTextAligned(writer.getDirectContentUnder(),Element.ALIGN_CENTER, new Phrase("FOOBAR FILM FESTIVAL", FONT),297.5f, 421, writer.getPageNumber() % 2 == 1 ? 45 : -45);}}/*** Creates a PDF document.* @param filename the path to the new PDF document* @throws    DocumentException * @throws    IOException* @throws    SQLException*/public void createPdf(String filename)throws IOException, DocumentException, SQLException {// step 1Document document = new Document(PageSize.A4, 36, 36, 54, 36);// step 2PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(RESULT));TableHeader event = new TableHeader();writer.setPageEvent(event);writer.setPageEvent(new Watermark());// step 3document.open();// step 4// 新建页面数据...document.add(new Phrase("Hello Page 1."));document.newPage();document.add(new Phrase("Hello Page 2."));document.newPage();document.add(new Phrase("Hello Page 3."));document.newPage();document.add(new Phrase("Hello Page 4."));// step 5document.close();}/*** Main method.** @param    args    no arguments needed* @throws DocumentException * @throws IOException * @throws SQLException*/public static void main(String[] args)throws IOException, DocumentException, SQLException {new MovieCountries2().createPdf(RESULT);}
}

创建幻灯片