java提取PDF文字坐标

常用java操作PDF的库有PDFbox和itext，下面我会介绍如何使用PDFbox和itext来提取PDF的文字坐标。

一、itext提取文字坐标

1、通过定义一个类实现RenderListener，可以通过里面的几个方法来操作PDF中的文字和图片

import java.awt.Color;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.ArrayList;import java.util.HashMap;import java.util.HashSet;import java.util.List;import java.util.Map;import javax.imageio.ImageIO;import com.itextpdf.awt.geom.Rectangle2D;import com.itextpdf.awt.geom.RectangularShape;import com.itextpdf.text.BaseColor;import com.itextpdf.text.Rectangle;import com.itextpdf.text.pdf.PdfContentByte;import com.itextpdf.text.pdf.parser.ImageRenderInfo;import com.itextpdf.text.pdf.parser.RenderListener;import com.itextpdf.text.pdf.parser.TextRenderInfo;public class TestRenderListener implements RenderListener {//用来存放文字的矩形List<Rectangle2D.Float> rectText = new ArrayList<Rectangle2D.Float>();//用来存放文字List<String> textList = new ArrayList<String>();//用来存放文字的y坐标List<Float> listY = new ArrayList<Float>();//用来存放每一行文字的坐标位置List<Map<String,Rectangle2D.Float>> rows_text_rect = new ArrayList<>();//PDF文件的路径protected String filepath = null;public TestRenderListener() {}//step 2,遇到"BT"执行@Overridepublic void beginTextBlock() {// TODO Auto-generated method stub}//step 3/*** 文字主要处理方法*/@Overridepublic void renderText(TextRenderInfo renderInfo) {//获取文字的下面的矩形//Rectangle2D.Float rectBase = renderInfo.getBaseline().getBoundingRectange();String text = renderInfo.getText();if(text.length() > 0){RectangularShape rectBase = renderInfo.getBaseline().getBoundingRectange();//获取文字下面的矩形Rectangle2D.Float rectAscen = renderInfo.getAscentLine().getBoundingRectange();//计算出文字的边框矩形float leftX = (float) rectBase.getMinX();float leftY = (float) rectBase.getMinY()-1;float rightX = (float) rectAscen.getMaxX();float rightY = (float) rectAscen.getMaxY()+1;Rectangle2D.Float rect = new Rectangle2D.Float(leftX, leftY, rightX - leftX, rightY - leftY);System.out.println("text:"+text+"--x:"+rect.x + "--y:"+rect.y + "--width:"+rect.width + "--height:"+rect.height);if(listY.contains(rect.y)){int index = listY.indexOf(rect.y);float tempx = rect.x > rectText.get(index).x ? rectText.get(index).x : rect.x;rectText.set(index,new Rectangle2D.Float(tempx,rect.y,rect.width + rectText.get(index).width,rect.height));textList.set(index,textList.get(index) + text);}else{rectText.add(rect);textList.add(text);listY.add(rect.y);}Map<String,Rectangle2D.Float> map = new HashMap<>();map.put(text,rect);rows_text_rect.add(map);}}//step 4(最后执行的，只执行一次)，遇到“ET”执行@Overridepublic void endTextBlock() {// TODO Auto-generated method stub}//step 1(图片处理方法)@Overridepublic void renderImage(ImageRenderInfo renderInfo) {}}

2、使用自定义的类来实现获取PDF的文字坐标

PdfReader reader = new PdfReader(pdfPath);//新建一个PDF解析对象PdfReaderContentParser parser = new PdfReaderContentParser(reader);//包含了PDF页面的信息，作为处理的对象PdfStamper stamper = new PdfStamper(reader, new FileOutputStream("d:/test.pdf"));for(int i = 1;i <= reader.getNumberOfPages();i++){//新建一个ImageRenderListener对象，该对象实现了RenderListener接口，作为处理PDF的主要类TestRenderListener listener = new TestRenderListener();//解析PDF，并处理里面的文字parser.processContent(i, listener);//获取文字的矩形边框List<Rectangle2D.Float> rectText = listener.rectText;List<String> textList = listener.textList;List<Float> listY = listener.listY;List<Map<String,Rectangle2D.Float>> list_text = listener.rows_text_rect;for(int k = 0;k < list_text.size();k++){Map<String,Rectangle2D.Float> map = list_text.get(k);for(Map.Entry<String, Rectangle2D.Float>entry:map.entrySet()){System.out.println(entry.getKey()+"---"+entry.getValue());}

}}

二、PDFbox获取文字坐标

PDFbox与itext不同的是，PDFbox只能一个一个字的提取PDF的文字坐标，而itext是一段一段提取的。

PDFbox版本：1.8.13，不同版本可能部分代码写法不同。

import java.io.*;import org.apache.pdfbox.exceptions.InvalidPasswordException;import org.apache.pdfbox.pdmodel.PDDocument;import org.apache.pdfbox.pdmodel.PDPage;import org.apache.mon.PDStream;import org.apache.pdfbox.util.PDFTextStripper;import org.apache.pdfbox.util.TextPosition;import java.io.IOException;import java.util.ArrayList;import java.util.List;public class PrintTextLocations extends PDFTextStripper {static List<Float> list_postion = new ArrayList<Float>();static List<String> list_text = new ArrayList<String>();public PrintTextLocations() throws IOException {super.setSortByPosition(true);}public static void main(String[] args) throws Exception {PDDocument document = null;try {File input = new File("D://result.pdf");document = PDDocument.load(input);if (document.isEncrypted()) {document.decrypt("");}PrintTextLocations printer = new PrintTextLocations();List allPages = document.getDocumentCatalog().getAllPages();for (int i = 0; i < allPages.size(); i++) {PDPage page = (PDPage) allPages.get(i);System.out.println("Processing page: " + i);PDStream contents = page.getContents();if (contents != null) {printer.processStream(page, page.findResources(), page.getContents().getStream());}}} finally {if (document != null) {document.close();}}System.out.println(list_text.size());for(int i = 0;i < list_text.size();i++){System.out.println(list_text.get(i) );}}/*** @param text The text to be processed*/@Override /* this is questionable, not sure if needed... */protected void processTextPosition(TextPosition text) {System.out.println("String[" + text.getXDirAdj() + ","+ text.getYDirAdj() + " fs=" + text.getFontSize() + " xscale="+ text.getXScale()+ " yscale="+ text.getYScale() + " height=" + text.getHeightDir() + " space="+ text.getWidthOfSpace() + " width="+ text.getWidthDirAdj() + " x="+ text.getX() + " y="+ text.getY() + " y1="+ text.getTextPos().getYPosition() + " x1="+ text.getTextPos().getXPosition() + " x1="+ text.getTextPos().getXScale() + " x1="+ text.getTextPos().getYScale() + "]" + text.getCharacter());}}