[PDFBox]后台操作pdf的工具类

　　PDFBox是Apache下的一个操作pdf的类库。其也提供了一个命令行的工具，也提供了java调用的第三方类库。

　　下载地址:https://pdfbox.apache.org/

　　

　　下面的实验基于JDK8+pdfbox-2.0.13.jar+pdfbox-app-2.0.13.jar(命令行工具库)

1.命令行使用

　　文档参考:https://pdfbox.apache.org/2.0/commandline.html

　　命令行工具可以提取pdf中的图片、文本，合并pdf与拆分pdf，pdf转换为图片等操作。

1.提取图片

java -jar pdfbox-app-2.0..jar ExtractImages ./.pdf

　　会在同文件夹下提取出pdf中的图片。

2.提取文字

java -jar pdfbox-app-2.0..jar ExtractText ./.pdf ./text.txt

　　当然还可以指定起始页号等参数。

3.pdf转换为图片

java -jar pdfbox-app-2.0..jar PDFToImage ./.pdf

　　结果每页生成一张图片。当然可以指定起始页号、生产图片的名称前缀等信息。默认生成的图片命名如下:(pdfname+page)

　　还有许多命令行操作可以参考官网的文档，对于参数都有详细的解释。这种方式可以封装为工具类用Runtime多线程执行操作pdf。

2.Java中作为类库使用

　　感觉这个工具还不是太方便，写入pdf表格等直接操作pdf的可以考虑用itext代替。这个就当做命令行工具实现pdf转换图片、提取文字等操作就可以了。关于itext的使用参考:https://www.cnblogs.com/qlqwjy/p/8213989.html

依赖的jar包:

commons-logging-1.0.4.jar、pdfbox-2.0.13.jar、fontbox-2.0.13.jar

package cn.qlq;

import java.io.File;
import java.io.IOException;
import java.util.List;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.PDPageContentStream.AppendMode;
import org.apache.pdfbox.pdmodel.encryption.AccessPermission;
import org.apache.pdfbox.pdmodel.encryption.InvalidPasswordException;
import org.apache.pdfbox.pdmodel.font.PDFont;
import org.apache.pdfbox.pdmodel.font.PDType1Font;
import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
import org.apache.pdfbox.pdmodel.interactive.action.PDAction;
import org.apache.pdfbox.pdmodel.interactive.action.PDActionJavaScript;
import org.apache.pdfbox.pdmodel.interactive.action.PDActionURI;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotation;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationLink;
import org.apache.pdfbox.text.PDFTextStripper;

public class PDFBoxTest {
    public static void main(String[] args) throws IOException {
        ReplaceURLs();
    }

    /**
     * 替换pdf中的连接的url跳转地址，但是显示的不会变，只是修改点击跳转的地址
     *
     * @throws InvalidPasswordException
     * @throws IOException
     */
    public static void ReplaceURLs() throws InvalidPasswordException, IOException {
        PDDocument doc = null;
        try {
            doc = PDDocument.load(new File("G:/qjl.pdf"));
            int pageNum = 0;
            for (PDPage page : doc.getPages()) {
                pageNum++;
                List<PDAnnotation> annotations = page.getAnnotations();

                for (PDAnnotation annotation : annotations) {
                    PDAnnotation annot = annotation;
                    if (annot instanceof PDAnnotationLink) {
                        PDAnnotationLink link = (PDAnnotationLink) annot;
                        PDAction action = link.getAction();
                        if (action instanceof PDActionURI) {
                            PDActionURI uri = (PDActionURI) action;
                            String oldURI = uri.getURI();
                            String newURI = "http://pdfbox.apache.org";
                            System.out.println("Page " + pageNum + ": Replacing " + oldURI + " with " + newURI);
                            uri.setURI(newURI);
                        }
                    }
                }
                doc.save("G:/qjl_1.pdf");
            }
        } finally {
            if (doc != null) {
                doc.close();
            }
        }
    }

    /**
     * 删除PDF里面的指定页
     *
     * @throws IOException
     * @throws InvalidPasswordException
     */
    public static void removePdfPage() throws IOException, InvalidPasswordException {
        try (PDDocument document = PDDocument.load(new File("G:/1.pdf"))) {
            if (document.isEncrypted()) {
                throw new IOException("Encrypted documents are not supported for this example");
            }
            if (document.getNumberOfPages() <= 1) {
                throw new IOException(
                        "Error: A PDF document must have at least one page, " + "cannot remove the last page!");
            }
            document.removePage(1);// 删除第2页
            System.out.println("ssssssssssssss");
            document.save("G:/1_1.pdf");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * PDF中增加图片
     *
     * @throws IOException
     * @throws InvalidPasswordException
     */
    public static void addImg2PDF() throws IOException, InvalidPasswordException {
        try (PDDocument doc = PDDocument.load(new File("G:/blank.pdf"))) {
            PDPage page = doc.getPage(0);
            PDImageXObject pdImage = PDImageXObject.createFromFile("G:/0101.jpg", doc);

            try (PDPageContentStream contentStream = new PDPageContentStream(doc, page, AppendMode.APPEND, true,
                    true)) {
                // contentStream.drawImage(ximage, 20, 20 );
                // better method inspired by
                // http://*.com/a/22318681/535646
                // reduce this value if the image is too large
                float scale = 1f;
                contentStream.drawImage(pdImage, 20, 20, pdImage.getWidth() * scale, pdImage.getHeight() * scale);
            }
            doc.save("G:/blank.pdf");
        }
    }

    /**
     * PDF文件中增加JS脚本
     *
     * @throws IOException
     * @throws InvalidPasswordException
     */
    public static void addJavaScript2PDF() throws IOException, InvalidPasswordException {
        try (PDDocument document = PDDocument.load(new File("G:/blank.pdf"))) {
            PDActionJavaScript javascript = new PDActionJavaScript(
                    "app.alert( {cMsg: 'PDFBox rocks!', nIcon: 3, nType: 0, cTitle: 'PDFBox Javascript example' } );");
            document.getDocumentCatalog().setOpenAction(javascript);
            if (document.isEncrypted()) {
                throw new IOException("Encrypted documents are not supported for this example");
            }
            document.save("G:/blank.pdf");
        }
    }

    /**
     * 阅读PDF文件的内容，支持阅读中文(如果需要阅读指定页面的PDF自己改写此方法)
     *
     * @throws IOException
     * @throws InvalidPasswordException
     */
    public static void readPDFText() throws IOException, InvalidPasswordException {
        try (PDDocument document = PDDocument.load(new File("G:/jl.pdf"))) {
            AccessPermission ap = document.getCurrentAccessPermission();
            if (!ap.canExtractContent()) {
                throw new IOException("You do not have permission to extract text");
            }

            PDFTextStripper stripper = new PDFTextStripper();

            stripper.setSortByPosition(true);

            for (int p = 1; p <= document.getNumberOfPages(); ++p) {
                stripper.setStartPage(p);
                stripper.setEndPage(p);

                String text = stripper.getText(document);

                String pageStr = String.format("page %d:", p);
                System.out.println(pageStr);
                for (int i = 0; i < pageStr.length(); ++i) {
                    System.out.print("-");
                }
                System.out.println();
                System.out.println(text.trim());
                System.out.println();
            }
        }
    }

    /**
     * 创建空的PDF文件并且添加一个空白页，多页可以插入多个PDPage
     *
     * @throws IOException
     */
    public static void createBlankPDF() throws IOException {
        String filename = "G:/blank.pdf";

        try (PDDocument doc = new PDDocument()) {
            // a valid PDF document requires at least one page
            PDPage blankPage = new PDPage();
            doc.addPage(blankPage);
            doc.save(filename);
        }
    }

    /**
     * 图片转换为PDF文件
     *
     * @throws IOException
     */
    public static void img2PDF() throws IOException {
        String imagePath = "G:/0101.jpg";
        String pdfPath = "G:/0101.pdf";

        try (PDDocument doc = new PDDocument()) {
            PDPage page = new PDPage();
            doc.addPage(page);

            PDImageXObject pdImage = PDImageXObject.createFromFile(imagePath, doc);

            try (PDPageContentStream contents = new PDPageContentStream(doc, page)) {
                contents.drawImage(pdImage, 20, 20);

            }
            doc.save(pdfPath);
        }
    }

    /**
     * 创建PDF文件并写入内容(暂时不支持写入中文)
     *
     * @throws IOException
     */
    public static void createPDF() throws IOException {
        String filename = "G:/Test.pdf";
        String message = "pdf";// 字体不能有中文，暂时不支持中文

        try (PDDocument doc = new PDDocument()) {
            PDPage page = new PDPage();
            doc.addPage(page);

            PDFont font = PDType1Font.HELVETICA_BOLD;

            try (PDPageContentStream contents = new PDPageContentStream(doc, page)) {
                contents.beginText();
                contents.setFont(font, 12);
                contents.newLineAtOffset(100, 700);
                contents.showText(message);
                contents.endText();
            }

            doc.save(filename);
        }
    }
}