Develop Reference

how to read conditional text from PDF?

I want to read a particular section in a PDF. Hows that possible? like: if you visit the URl: Suppose I want to get only Part 1 data.
URL url = new URL("https://www.uscis.gov/sites/default/files/files/form/i-129.pdf");
InputStream is = url.openStream();
BufferedInputStream fileParse = new BufferedInputStream(is);
PDDocument document = null;
document = PDDocument.load(fileParse);
String pdfContent = new PDFTextStripper().getText(document);
System.out.println(pdfContent);

In your specific case you can set the start and end pages of the stripper such that you don't get the full document each time, then use some simple string operations to get what you need.
Here is a complete, more generic working example based on your code.
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.text.PDFTextStripper;
import java.io.BufferedInputStream;
import java.io.InputStream;
import java.net.URL;
public class App {
public static void main(String...args) throws Exception {
String path = "..."; // replace with whatever path you need
String startDelimiter = "..."; // replace with wherever the start is
String endDelimiter = "...";
URL url = new URL(path);
InputStream is = url.openStream();
BufferedInputStream fileParse = new BufferedInputStream(is);
PDDocument document = PDDocument.load(fileParse);
PDFTextStripper stripper = new PDFTextStripper();
// set this stuff if you know more or less where it should be in the pdf to avoid stripping the whole thing
stripper.setStartPage(1);
stripper.setEndPage(3);
// get the content
String content = stripper.getText(document);
String searchedContent = content.substring(content.indexOf(startDelimiter), content.indexOf(endDelimiter));
System.out.println(searchedContent);
}
}
If, on the other hand, you don't know where in the document you're looking, with a bit of work you can search the document in order to get the start page and end page or other stuff. See this similar question.

Merge PDF documents and images into one PDF

I have read examples in merging PDF documents section however I couldn't develop more optimal solution for the following task:
I would like to merge series of PDF and image files coming in any order (original post). The inefficiency comes from the fact that I need to create dummy 1-page PDF file for image using PdfWriter and then read it back from byte array using PdfReader.
Question: Is there more efficient way of doing the same (maybe via PdfCopy#addPage())?
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Image;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfSmartCopy;
import com.itextpdf.text.pdf.PdfWriter;
/**
* Helper class that creates PDF from given image(s) (JPEG, PNG, ...) or PDFs.
*/
public class MergeToPdf {
public static void main(String[] args) throws IOException, DocumentException {
if (args.length < 2) {
System.err.println("At least two arguments are required: in1.pdf [, image2.jpg ...], out.pdf");
System.exit(1);
}
Document mergedDocument = new Document();
PdfSmartCopy pdfCopy = new PdfSmartCopy(mergedDocument, new FileOutputStream(args[args.length - 1]));
mergedDocument.open();
for (int i = 0; i < args.length - 1; i++) {
PdfReader reader;
if (args[i].toLowerCase().endsWith(".pdf")) {
System.out.println("Adding PDF " + args[i] + "...");
// Copy PDF document:
reader = new PdfReader(args[i]);
}
else {
System.out.println("Adding image " + args[i] + "...");
final ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
final Document imageDocument = new Document();
PdfWriter.getInstance(imageDocument, byteStream);
imageDocument.open();
// Create single page with the dimensions as source image and no margins:
Image image = Image.getInstance(args[i]);
image.setAbsolutePosition(0, 0);
imageDocument.setPageSize(image);
imageDocument.newPage();
imageDocument.add(image);
imageDocument.close();
// Copy PDF document with only one page carrying the image:
reader = new PdfReader(byteStream.toByteArray());
}
pdfCopy.addDocument(reader);
reader.close();
}
mergedDocument.close();
}
}

Java - Text Extraction from PDF using OCR

I have a pdf file (some part of it given below), and want to extract text from it. I have used PDFTextStream, but it doesn't work with this file. (However it worked with other file, that has simple text).
What other OCR libraries are capable of doing it?
Please Help.
Thank you.

I tried with PDFBox and it produced satisfactory results.
Here is the code to extract text from PDF using PDFBox:
import java.io.*;
import org.apache.pdfbox.pdmodel.*;
import org.apache.pdfbox.text.PDFTextStripper;
import org.apache.pdfbox.util.*;
public class PDFTest {
public static void main(String[] args){
PDDocument pd;
BufferedWriter wr;
try {
File input = new File("C:/BillOCR/data/bill.pdf"); // The PDF file from where you would like to extract
File output = new File("D:/SampleText.txt"); // The text file where you are going to store the extracted data
pd = PDDocument.load(input);
System.out.println(pd.getNumberOfPages());
System.out.println(pd.isEncrypted());
pd.save("CopyOfBill.pdf"); // Creates a copy called "CopyOfInvoice.pdf"
PDFTextStripper stripper = new PDFTextStripper();
stripper.setStartPage(1); //Start extracting from page 3
stripper.setEndPage(1); //Extract till page 5
wr = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(output)));
stripper.writeText(pd, wr);
if (pd != null) {
pd.close();
}
// I use close() to flush the stream.
wr.close();
} catch (Exception e){
e.printStackTrace();
}
}
}

How to read raw data, say only text, from a file(word document, excel) without format? [duplicate]

The strings I'm (programmatically) getting from MS Word files when using Apache POI are not the same text I can look at when I open the files with MS Word.
When using the following code:
File someFile = new File("some\\path\\MSWFile.doc");
InputStream inputStrm = new FileInputStream(someFile);
HWPFDocument wordDoc = new HWPFDocument(inputStrm);
System.out.println(wordDoc.getText());
the output is a single line with many 'invalid' characters (yes, the 'boxes'), and many unwanted strings, like "FORMTEXT", "HYPERLINK \l "_Toc##########"" ('#' being numeric digits), "PAGEREF _Toc########## \h 4", etc.
The following code "fixes" the single-line problem, but maintains all the invalid characters and unwanted text:
File someFile = new File("some\\path\\MSWFile.doc");
InputStream inputStrm = new FileInputStream(someFile);
WordExtractor wordExtractor = new WordExtractor(inputStrm);
for(String paragraph:wordExtractor.getParagraphText()){
System.out.println(paragraph);
}
I don't know if I'm using the wrong method for extracting the text, but that's what I've come up with when looking at POI's quick-guide. If I am, what is the correct approach?
If that output is correct, is there a standard way for getting rid of the unwanted text, or will I have to write a filter of my own?

This class can read both .doc and .docx files in Java. For this I'm using tika-app-1.2.jar:
/*
* This class is used to read .doc and .docx files
*
* #author Developer
*
*/
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.URL;
import org.apache.tika.detect.DefaultDetector;
import org.apache.tika.detect.Detector;
import org.apache.tika.io.TikaInputStream;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.parser.AutoDetectParser;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.parser.Parser;
import org.apache.tika.sax.BodyContentHandler;
import org.xml.sax.ContentHandler;
class TextExtractor {
private OutputStream outputstream;
private ParseContext context;
private Detector detector;
private Parser parser;
private Metadata metadata;
private String extractedText;
public TextExtractor() {
context = new ParseContext();
detector = new DefaultDetector();
parser = new AutoDetectParser(detector);
context.set(Parser.class, parser);
outputstream = new ByteArrayOutputStream();
metadata = new Metadata();
}
public void process(String filename) throws Exception {
URL url;
File file = new File(filename);
if (file.isFile()) {
url = file.toURI().toURL();
} else {
url = new URL(filename);
}
InputStream input = TikaInputStream.get(url, metadata);
ContentHandler handler = new BodyContentHandler(outputstream);
parser.parse(input, handler, metadata, context);
input.close();
}
public void getString() {
//Get the text into a String object
extractedText = outputstream.toString();
//Do whatever you want with this String object.
System.out.println(extractedText);
}
public static void main(String args[]) throws Exception {
if (args.length == 1) {
TextExtractor textExtractor = new TextExtractor();
textExtractor.process(args[0]);
textExtractor.getString();
} else {
throw new Exception();
}
}
}
To compile:
javac -cp ".:tika-app-1.2.jar" TextExtractor.java
To run:
java -cp ".:tika-app-1.2.jar" TextExtractor SomeWordDocument.doc

There are two options, one provided directly in Apache POI, the other via Apache Tika (which uses Apache POI internally).
The first option is to use WordExtractor, but wrap it in a call to stripFields(String) when calling it. That will remove the text based fields included in the text, things like HYPERLINK that you've seen. Your code would become:
NPOIFSFileSystem fs = new NPOIFSFileSytem(file);
WordExtractor extractor = new WordExtractor(fs.getRoot());
for(String rawText : extractor.getParagraphText()) {
String text = extractor.stripFields(rawText);
System.out.println(text);
}
The other option is to use Apache Tika. Tika provides text extraction, and metadata, for a wide variety of files, so the same code will work for .doc, .docx, .pdf and many others too. To get clean, plain text of your word document (you can also get XHTML if you'd rather), you'd do something like:
TikaConfig tika = TikaConfig.getDefaultConfig();
TikaInputStream stream = TikaInputStream.get(file);
ContentHandler handler = new BodyContentHandler();
Metadata metadata = new Metadata();
tika.getParser().parse(input, handler, metadata, new ParseContext());
String text = handler.toString();

Try this, works for me and is purely a POI solution. You will have to look for the HWPFDocument counterpart though. Make sure the document you are reading predates Word 97, else use XWPFDocument like I do.
InputStream inputstream = new FileInputStream(m_filepath);
//read the file
XWPFDocument adoc= new XWPFDocument(inputstream);
//and place it in a xwpf format
aString = new XWPFWordExtractor(adoc).getText();
//gets the full text
Now if you want certain parts you can use the getparagraphtext but dont use the text extractor, use it directly on the paragraph like this
for (XWPFParagraph p : adoc.getParagraphs())
{
System.out.println(p.getParagraphText());
}

Editing PDF text using Java

Is there a way I can edit a PDF from Java?
I have a PDF document which contains placeholders for text that I need to be replaced using Java, but all the libraries that I saw created PDF from scratch and small editing functionality.
Is there anyway I can edit a PDF or is this impossible?

You can do it with iText. I tested it with following code. It adds a chunk of text and a red circle over each page of an existing PDF.
/* requires itextpdf-5.1.2.jar or similar */
import java.io.*;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.pdf.*;
public class AddContentToPDF {
public static void main(String[] args) throws IOException, DocumentException {
/* example inspired from "iText in action" (2006), chapter 2 */
PdfReader reader = new PdfReader("C:/temp/Bubi.pdf"); // input PDF
PdfStamper stamper = new PdfStamper(reader,
new FileOutputStream("C:/temp/Bubi_modified.pdf")); // output PDF
BaseFont bf = BaseFont.createFont(
BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED); // set font
//loop on pages (1-based)
for (int i=1; i<=reader.getNumberOfPages(); i++){
// get object for writing over the existing content;
// you can also use getUnderContent for writing in the bottom layer
PdfContentByte over = stamper.getOverContent(i);
// write text
over.beginText();
over.setFontAndSize(bf, 10); // set font and size
over.setTextMatrix(107, 740); // set x,y position (0,0 is at the bottom left)
over.showText("I can write at page " + i); // set text
over.endText();
// draw a red circle
over.setRGBColorStroke(0xFF, 0x00, 0x00);
over.setLineWidth(5f);
over.ellipse(250, 450, 350, 550);
over.stroke();
}
stamper.close();
}
}

I modified the code found a bit and it was working as follows
public class Principal {
public static final String SRC = "C:/tmp/244558.pdf";
public static final String DEST = "C:/tmp/244558-2.pdf";
public static void main(String[] args) throws IOException, DocumentException {
File file = new File(DEST);
file.getParentFile().mkdirs();
new Principal().manipulatePdf(SRC, DEST);
}
public void manipulatePdf(String src, String dest) throws IOException, DocumentException {
PdfReader reader = new PdfReader(src);
PdfDictionary dict = reader.getPageN(1);
PdfObject object = dict.getDirectObject(PdfName.CONTENTS);
PdfArray refs = null;
if (dict.get(PdfName.CONTENTS).isArray()) {
refs = dict.getAsArray(PdfName.CONTENTS);
} else if (dict.get(PdfName.CONTENTS).isIndirect()) {
refs = new PdfArray(dict.get(PdfName.CONTENTS));
}
for (int i = 0; i < refs.getArrayList().size(); i++) {
PRStream stream = (PRStream) refs.getDirectObject(i);
byte[] data = PdfReader.getStreamBytes(stream);
stream.setData(new String(data).replace("NULA", "Nulo").getBytes());
}
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest));
stamper.close();
reader.close();
}
}

Take a look at iText and this sample code

Take a look at aspose and this sample code

I've done this using LibreOffice Draw.
You start by manually opening a pdf in Draw, checking that it renders OK, and saving it as a Draw .odg file.
That's a zipped xml file, so you can modify it in code to find and replace the placeholders.
Next (from code) you use a command line call to Draw to generate the pdf.
Success!
The main issue is that Draw doesn't handle fonts embedded in a pdf. If the font isn't also installed on your system - then it will render oddly, as Draw will replace it with a standard one that inevitably has different sizing.
If this approach is of interest, I'll put together some shareable code.