java使用 pdfbox 操作pdf文件（添加、移除水印、读取文本内容）

12、使用 pdfbox 操作pdf文件（工具类）

package com.lingxu.base.common.util;

import com.aspose.words.Document;
import com.aspose.words.SaveFormat;
import org.apache.pdfbox.Loader;
import org.apache.pdfbox.contentstream.operator.Operator;
import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.cos.COSString;
import org.apache.pdfbox.pdfparser.PDFStreamParser;
import org.apache.pdfbox.pdfwriter.ContentStreamWriter;
import org.apache.pdfbox.pdmodel.*;
import org.apache.pdfbox.pdmodel.common.PDStream;
import org.apache.pdfbox.pdmodel.font.PDFont;
import org.apache.pdfbox.pdmodel.font.PDType1Font;
import org.apache.pdfbox.pdmodel.graphics.state.PDExtendedGraphicsState;
import org.apache.pdfbox.util.Matrix;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * @author Li
 */
public class WordTransitionPdf {


    //替换pdf文本内容
    public static void replaceText(PDPage page, String searchString, String replacement) throws IOException {
        PDFStreamParser parser = new PDFStreamParser(page);
        List<?> tokens = parser.parse();
        for (int j = 0; j < tokens.size(); j++) {
            Object next = tokens.get(j);
            if (next instanceof Operator) {
                Operator op = (Operator) next;
                String pstring = "";
                int prej = 0;
                if (op.getName().equals("Tj")) {
                    COSString previous = (COSString) tokens.get(j - 1);
                    String string = previous.getString();
                    string = string.replaceFirst(searchString, replacement);
                    previous.setValue(string.getBytes());
                } else if (op.getName().equals("TJ")) {
                    COSArray previous = (COSArray) tokens.get(j - 1);
                    for (int k = 0; k < previous.size(); k++) {
                        Object arrElement = previous.getObject(k);
                        if (arrElement instanceof COSString) {
                            COSString cosString = (COSString) arrElement;
                            String string = cosString.getString();

                            if (j == prej) {
                                pstring += string;
                            } else {
                                prej = j;
                                pstring = string;
                            }
                        }
                    }
                    if (searchString.equals(pstring.trim())) {
                        COSString cosString2 = (COSString) previous.getObject(0);
                        cosString2.setValue(replacement.getBytes());
                        int total = previous.size() - 1;
                        for (int k = total; k > 0; k--) {
                            previous.remove(k);
                        }
                    }
                }
            }
        }
        List<PDStream> contents = new ArrayList<>();
        Iterator<PDStream> streams = page.getContentStreams();
        while (streams.hasNext()) {
            PDStream updatedStream = streams.next();
            OutputStream out = updatedStream.createOutputStream(COSName.FLATE_DECODE);
            ContentStreamWriter tokenWriter = new ContentStreamWriter(out);
            tokenWriter.writeTokens(tokens);
            contents.add(updatedStream);
            out.close();
        }
        page.setContents(contents);
    }

    //移除图片水印
    public static void removeImage(PDPage page, String cosName) {
        PDResources resources = page.getResources();
        COSDictionary dict1 = resources.getCOSObject();
        resources.getXObjectNames().forEach(e -> {
            if (resources.isImageXObject(e)) {
                COSDictionary dict2 = dict1.getCOSDictionary(COSName.XOBJECT);
                if (e.getName().equals(cosName)) {
                    dict2.removeItem(e);
                }
            }
            page.setResources(new PDResources(dict1));
        });
    }


    //移除文字水印
    public static boolean removeWatermark(File file) {
        try {
            //通过文件名加载文档
            PDDocument document = Loader.loadPDF(file);
            PDPageTree pages = document.getPages();
            Iterator<PDPage> iter = pages.iterator();
            while (iter.hasNext()) {
                PDPage page = iter.next();
                //去除文字水印
//                replaceText(page, "Evaluation Only. Created with Aspose.Words. Copyright 2003-2021 Aspose", "");
//                replaceText(page, "Pty Ltd.", "");
//                replaceText(page, "Created with an evaluation copy of Aspose.Words. To discover the full", "");
//                replaceText(page, "versions of our APIs please visit: https://products.aspose.com/words/", "");
//                replaceText(page, "This document was truncated here because it was created in the Evaluation", "");


                replaceText(page, "Evaluation Only. Created with Aspose.Words. Copyright 2003-2021 Aspose Pty Ltd.", "");
                replaceText(page, "Created with an evaluation copy of Aspose.Words. To discover the full versions of our APIs", "");
                replaceText(page, "please visit: https://products.aspose.com/words/", "");
                replaceText(page, "This document was truncated here because it was created in the Evaluation Mode.", "");
                //去除图片水印
                removeImage(page, "X1");
            }
//            document.removePage(document.getNumberOfPages() - 1);
            file.delete();
            document.save(file);
            document.close();
            return true;
        } catch (IOException ex) {
            ex.printStackTrace();
            return false;
        }

    }


    //doc文件转pdf(目前最大支持21页)
    public static String doc2pdf(String wordPath) {
        long old = System.currentTimeMillis();
        String pdfPath = null;
        try {
            //新建一个pdf文档
            pdfPath = wordPath.substring(0, wordPath.lastIndexOf(".")) + ".pdf";
            File file = new File(pdfPath);
            FileOutputStream os = new FileOutputStream(file);
            //Address是将要被转化的word文档
            Document doc = new Document(wordPath);
            //全面支持DOC, DOCX, OOXML, RTF HTML, OpenDocument, PDF, EPUB, XPS, SWF 相互转换
            doc.save(os, SaveFormat.PDF);
            os.close();
            //去除水印
            removeWatermark(new File(pdfPath));
            //转化用时
            long now = System.currentTimeMillis();
            System.out.println("Word 转 Pdf 共耗时：" + ((now - old) / 1000.0) + "秒");

        } catch (Exception e) {
            System.out.println("Word 转 Pdf 失败...");
            e.printStackTrace();
        }
        return pdfPath;
    }

    //    添加水印
    public static void watermarkPDF(File fileStored) throws Exception {
        File tmpPDF;
        PDDocument doc;

    tmpPDF = new File(fileStored.getParent() + System.getProperty("file.separator") + "Tmp_" + fileStored.getName());
//        tmpPDF = new File(fileStored.getParent() + System.getProperty("file.separator") + fileStored.getName());
//		doc = PDDocument.loader(fileStored);
        doc = Loader.loadPDF(fileStored);
        doc.setAllSecurityToBeRemoved(true);
        for (PDPage page : doc.getPages()) {
            PDPageContentStream cs = new PDPageContentStream(doc, page, PDPageContentStream.AppendMode.APPEND, true, true);
            String ts = "0000";
            PDFont font = PDType1Font.HELVETICA_OBLIQUE;
            float fontSize = 30.0f;
            PDResources resources = page.getResources();
            PDExtendedGraphicsState r0 = new PDExtendedGraphicsState();
            // 透明度
            r0.setNonStrokingAlphaConstant(0.2f);
            r0.setAlphaSourceFlag(true);
            cs.setGraphicsStateParameters(r0);
//			cs.setNonStrokingColor(200,0,0);//Red
            cs.beginText();
            cs.setFont(font, fontSize);
//根据水印文字大小长度计算横向坐标需要渲染几次水印
            float h = ts.length() * fontSize;
            for (int i = 0; i <= 10; i++) {
// 获取旋转实例
                cs.setTextMatrix(Matrix.getRotateInstance(-150, i * 100, 0));
                cs.showText(ts);
                for (int j = 0; j < 20; j++) {
                    cs.setTextMatrix(Matrix.getRotateInstance(-150, i * 100, j * h));
                    cs.showText(ts);
                }
            }
            cs.endText();
            cs.restoreGraphicsState();
            cs.close();
        }
        doc.save(tmpPDF);
    }

    //添加水印内容
    public static void watermarkPDF(File fileStored, String textContent) throws Exception {
        File tmpPDF;
        PDDocument doc;

        tmpPDF = new File(fileStored.getParent() + System.getProperty("file.separator") + "SQ_" + fileStored.getName());
//		tmpPDF = new File(fileStored.getParent() + System.getProperty("file.separator") +fileStored.getName());
//		doc = PDDocument.loader(fileStored);
        doc = Loader.loadPDF(fileStored);
        doc.setAllSecurityToBeRemoved(true);
        for (PDPage page : doc.getPages()) {
            PDPageContentStream cs = new PDPageContentStream(doc, page, PDPageContentStream.AppendMode.APPEND, true, true);
            String ts = textContent;
            PDFont font = PDType1Font.HELVETICA_OBLIQUE;
            float fontSize = 13;
            PDResources resources = page.getResources();
            PDExtendedGraphicsState r0 = new PDExtendedGraphicsState();
            // 透明度
            r0.setNonStrokingAlphaConstant(0.1f);
            r0.setAlphaSourceFlag(true);
            cs.setGraphicsStateParameters(r0);
//			cs.setNonStrokingColor(200,0,0);//Red
            cs.beginText();
            cs.setFont(font, fontSize);
            // 获取PDF页面大小
            float pageHeight = page.getMediaBox().getHeight();
            float pageWidth = page.getMediaBox().getWidth();

            // 根据纸张大小添加水印，30度倾斜
            for (int h = 10; h < pageHeight; h = h + 150) {
                for (int w = -10; w < pageWidth; w = w + 150) {
                    cs.setTextMatrix(Matrix.getRotateInstance(0.3, w, h));
                    cs.showText(ts);
                }
            }
根据水印文字大小长度计算横向坐标需要渲染几次水印
//            float h = ts.length() * fontSize;
//            for (int i = 0; i <= 10; i++) {
 获取旋转实例
//                cs.setTextMatrix(Matrix.getRotateInstance(-150, i * 100, 0));
//                cs.showText(ts);
                for (int j = 0; j < 20; j++) {
                    cs.setTextMatrix(Matrix.getRotateInstance(-150, i * 100, j * h));
                    cs.showText(ts);
                }
//            }
            cs.endText();
            cs.restoreGraphicsState();
            cs.close();
        }
        doc.save(tmpPDF);
//        doc.save(fileStored);
    }
}