Java Tutorial/PDF/Introduction

Материал из Java эксперт
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Create Empty page

   <source lang="java">

import java.io.FileOutputStream; import com.lowagie.text.Document; import com.lowagie.text.Paragraph; import com.lowagie.text.pdf.PdfWriter; public class MainClass { 

 public static void main(String[] args) throws Exception {
   Document document = new Document();
   PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("2.pdf"));
   document.open();
   writer.setPageEmpty(true);
   document.newPage();
   writer.setPageEmpty(false);
   document.newPage();
   document.add(new Paragraph("Hello World"));
   document.newPage();
   writer.setPageEmpty(true);
   document.newPage();
   document.close();
 }

}</source>





Create your first Pdf document with Java

   <source lang="java">

import java.io.FileOutputStream; import com.lowagie.text.Document; import com.lowagie.text.Paragraph; import com.lowagie.text.pdf.PdfWriter; public class GeneratesPDFFileWithText { 

 public static void main(String[] args) throws Exception {
   Document document = new Document();
   PdfWriter.getInstance(document, new FileOutputStream("HelloWorld.pdf"));
   document.open();
   document.add(new Paragraph("Hello World"));
   document.close();
 }

}</source>





inspects a PDF file

   <source lang="java">

import java.io.FileOutputStream; import java.io.PrintStream; import java.util.Iterator; import com.lowagie.text.pdf.PRStream; import com.lowagie.text.pdf.PRTokeniser; import com.lowagie.text.pdf.PdfArray; import com.lowagie.text.pdf.PdfDictionary; import com.lowagie.text.pdf.PdfIndirectReference; import com.lowagie.text.pdf.PdfLister; import com.lowagie.text.pdf.PdfName; import com.lowagie.text.pdf.PdfObject; import com.lowagie.text.pdf.PdfReader; public class MainClass { 

 public static void main(String[] args) throws Exception {
   PdfReader reader = new PdfReader("2.pdf");
   PrintStream list = new PrintStream(new FileOutputStream("2.txt"));
   PdfLister lister = new PdfLister(new PrintStream(list));
   PdfDictionary trailer = reader.getTrailer();
   lister.listDict(trailer);
   PdfIndirectReference info = (PdfIndirectReference) trailer.get(PdfName.INFO);
   lister.listAnyObject(info);
   lister.listAnyObject(reader.getPdfObject(info.getNumber()));
   PdfDictionary root = reader.getCatalog();
   lister.listDict(root);
   PdfDictionary outlines = (PdfDictionary) reader.getPdfObject(((PdfIndirectReference) root
       .get(PdfName.OUTLINES)).getNumber());
   lister.listDict(outlines);
   PdfObject first = reader.getPdfObject(((PdfIndirectReference) outlines.get(PdfName.FIRST))
       .getNumber());
   lister.listAnyObject(first);
   PdfDictionary pages = (PdfDictionary) reader.getPdfObject(((PdfIndirectReference) root
       .get(PdfName.PAGES)).getNumber());
   lister.listDict(pages);
   PdfArray kids = (PdfArray) pages.get(PdfName.KIDS);
   PdfIndirectReference kid_ref;
   PdfDictionary kid = null;
   for (Iterator i = kids.getArrayList().iterator(); i.hasNext();) {
     kid_ref = (PdfIndirectReference) i.next();
     kid = (PdfDictionary) reader.getPdfObject(kid_ref.getNumber());
     lister.listDict(kid);
   }
   PdfIndirectReference content_ref = (PdfIndirectReference) kid.get(PdfName.CONTENTS);
   PRStream content = (PRStream) reader.getPdfObject(content_ref.getNumber());
   lister.listDict(content);
   byte[] contentstream = PdfReader.getStreamBytes(content);
   list.println(new String(contentstream));
   PRTokeniser tokenizer = new PRTokeniser(contentstream);
   while (tokenizer.nextToken()) {
     if (tokenizer.getTokenType() == PRTokeniser.TK_STRING) {
       list.println(tokenizer.getStringValue());
     }
   }
 }

}</source>





PdfDictionary

   <source lang="java">

import java.io.FileOutputStream; import com.lowagie.text.Document; import com.lowagie.text.PageSize; import com.lowagie.text.pdf.BaseFont; import com.lowagie.text.pdf.PRIndirectReference; import com.lowagie.text.pdf.PRStream; import com.lowagie.text.pdf.PRTokeniser; import com.lowagie.text.pdf.PdfContentByte; import com.lowagie.text.pdf.PdfDictionary; import com.lowagie.text.pdf.PdfName; import com.lowagie.text.pdf.PdfReader; import com.lowagie.text.pdf.PdfTemplate; import com.lowagie.text.pdf.PdfWriter; public class MainClass { 

 public static void main(String[] args) throws Exception {
   Document document = new Document(PageSize.A6);
   PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("2.pdf"));
   document.open();
   PdfContentByte cb = writer.getDirectContent();
   BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
   cb.beginText();
   cb.setFontAndSize(bf, 12);
   cb.moveText(88.66f, 367);
   cb.showText("ld");
   cb.endText();
   PdfTemplate tmp = cb.createTemplate(250, 25);
   tmp.beginText();
   tmp.setFontAndSize(bf, 12);
   tmp.moveText(0, 7);
   tmp.showText("Hello People");
   tmp.endText();
   cb.addTemplate(tmp, 36, 343);
   document.close();
   PdfReader reader = new PdfReader("2.pdf");
   PdfDictionary page = reader.getPageN(1);
   PRIndirectReference objectReference = (PRIndirectReference) page.get(PdfName.CONTENTS);
   PRStream stream = (PRStream) PdfReader.getPdfObject(objectReference);
   byte[] streamBytes = PdfReader.getStreamBytes(stream);
   PRTokeniser tokenizer = new PRTokeniser(streamBytes);
   while (tokenizer.nextToken()) {
     if (tokenizer.getTokenType() == PRTokeniser.TK_STRING) {
       System.out.println(tokenizer.getStringValue());
     }
   }
 }

}</source>





PRTokeniser

   <source lang="java">

import java.io.FileOutputStream; import com.lowagie.text.Document; import com.lowagie.text.PageSize; import com.lowagie.text.Paragraph; import com.lowagie.text.pdf.PRIndirectReference; import com.lowagie.text.pdf.PRStream; import com.lowagie.text.pdf.PRTokeniser; import com.lowagie.text.pdf.PdfContentByte; import com.lowagie.text.pdf.PdfDictionary; import com.lowagie.text.pdf.PdfName; import com.lowagie.text.pdf.PdfReader; import com.lowagie.text.pdf.PdfWriter; public class MainClass { 

 public static void main(String[] args) throws Exception {
   Document document = new Document(PageSize.A6);
   PdfWriter.getInstance(document, new FileOutputStream("2.pdf"));
   document.open();
   document.add(new Paragraph("Hello World"));
   document.add(new Paragraph("Hello People"));
   document.close();
   PdfReader reader = new PdfReader("2.pdf");
   PdfDictionary page = reader.getPageN(1);
   PRIndirectReference objectReference = (PRIndirectReference) page.get(PdfName.CONTENTS);
   PRStream stream = (PRStream) PdfReader.getPdfObject(objectReference);
   byte[] streamBytes = PdfReader.getStreamBytes(stream);
   String contentStream = new String(streamBytes);
   System.out.println(contentStream);
   PRTokeniser tokenizer = new PRTokeniser(streamBytes);
   while (tokenizer.nextToken()) {
     if (tokenizer.getTokenType() == PRTokeniser.TK_STRING) {
       System.out.println(tokenizer.getStringValue());
     }
   }
   StringBuffer buf = new StringBuffer();
   int pos = contentStream.indexOf("Hello World") + 11;
   buf.append(contentStream.substring(0, pos));
   buf.append("Hello");
   buf.append(contentStream.substring(pos));
   String hackedContentStream = buf.toString();
   document = new Document(PageSize.A6);
   PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(
       "HelloWorldStreamHacked.pdf"));
   document.open();
   PdfContentByte cb = writer.getDirectContent();
   cb.setLiteral(hackedContentStream);
   document.close();
 }

}</source>





Read Pdf document to string

   <source lang="java">

import java.io.FileOutputStream; import com.lowagie.text.Document; import com.lowagie.text.PageSize; import com.lowagie.text.Paragraph; import com.lowagie.text.pdf.PdfReader; import com.lowagie.text.pdf.PdfStamper; import com.lowagie.text.pdf.PdfWriter; public class MainClass { 

 public static void main(String[] args) throws Exception {
   Document document = new Document(PageSize.A6);
   PdfWriter.getInstance(document, new FileOutputStream("2.pdf"));
   document.open();
   document.add(new Paragraph("Hello World"));
   document.add(new Paragraph("Hello People"));
   document.close();
   PdfReader reader = new PdfReader("2.pdf");
   byte[] streamBytes = reader.getPageContent(1);
   String contentStream = new String(streamBytes);
   System.out.println(contentStream);
   StringBuffer buf = new StringBuffer();
   int pos = contentStream.indexOf("Hello World") + 11;
   buf.append(contentStream.substring(0, pos));
   buf.append(", Hello ");
   buf.append(contentStream.substring(pos));
   String hackedContentStream = buf.toString();
   PdfStamper stamper = new PdfStamper(reader, new FileOutputStream("HelloWorldStreamHack.pdf"));
   reader.setPageContent(1, hackedContentStream.getBytes());
   stamper.close();
 }

}</source>





Tagged PDF

   <source lang="java">

import java.io.FileOutputStream; import com.lowagie.text.Document; import com.lowagie.text.pdf.BaseFont; import com.lowagie.text.pdf.PdfContentByte; import com.lowagie.text.pdf.PdfName; import com.lowagie.text.pdf.PdfStructureElement; import com.lowagie.text.pdf.PdfStructureTreeRoot; import com.lowagie.text.pdf.PdfWriter; public class MainClass { 

 public static void main(String[] args) throws Exception {
   Document document = new Document();
   PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("2.pdf"));
   writer.setTagged();
   document.open();
   PdfStructureTreeRoot root = writer.getStructureTreeRoot();
   PdfStructureElement eTop = new PdfStructureElement(root, new PdfName("Everything"));
   root.mapRole(new PdfName("Everything"), new PdfName("Sect"));
   PdfStructureElement e1 = new PdfStructureElement(eTop, PdfName.P);
   PdfStructureElement e2 = new PdfStructureElement(eTop, PdfName.P);
   PdfStructureElement e3 = new PdfStructureElement(eTop, PdfName.P);
   PdfContentByte cb = writer.getDirectContent();
   BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA, BaseFont.WINANSI, false);
   cb.setLeading(16);
   cb.setFontAndSize(bf, 12);
   cb.beginText();
   cb.setTextMatrix(50, 700);
   for (int k = 0; k < 2; ++k) {
     cb.beginMarkedContentSequence(e2);
     cb.newlineShowText("text2");
     cb.endMarkedContentSequence();
   }
   cb.endText();
   document.newPage();
   cb.setLeading(16);
   cb.setFontAndSize(bf, 12);
   cb.beginText();
   cb.setTextMatrix(50, 804);
   cb.beginMarkedContentSequence(e2);
   cb.newlineShowText("text2");
   cb.endMarkedContentSequence();
   cb.endText();
   cb.beginMarkedContentSequence(e3);
   cb.endMarkedContentSequence();
   document.close();
 }

}</source>





Update a Pdf document

   <source lang="java">

import java.io.FileOutputStream; import com.lowagie.text.Document; import com.lowagie.text.Element; import com.lowagie.text.Paragraph; import com.lowagie.text.pdf.BaseFont; import com.lowagie.text.pdf.PdfContentByte; import com.lowagie.text.pdf.PdfReader; import com.lowagie.text.pdf.PdfStamper; import com.lowagie.text.pdf.PdfWriter; public class MainClass { 

 public static void main(String[] args) throws Exception {
   Document.rupress = false;
   Document document = new Document();
   PdfWriter.getInstance(document, new FileOutputStream("2.pdf"));
   document.open();
   document.add(new Paragraph("Hello World"));
   document.close();
   PdfReader reader = new PdfReader("HelloWorld.pdf");
   PdfStamper stamper = new PdfStamper(reader, new FileOutputStream("updated.pdf"), "\0", true);
   PdfContentByte cb = stamper.getOverContent(1);
   cb.beginText();
   cb.showTextAligned(Element.ALIGN_LEFT, "Hello People", 36, 770, 0);
   cb.endText();
   stamper.close();
 }

}</source>


Источник — «http://www.jexp.ru/index.php?title=Java_Tutorial/PDF/Introduction&oldid=5576»