使用 Java 编辑 PDF 文本

java pdf

2022-09-01 13:23:40

有没有办法从Java编辑PDF？
我有一个PDF文档，其中包含需要使用Java替换的文本占位符，但是我看到的所有库都从头开始创建了PDF和小的编辑功能。
无论如何，我可以编辑PDF还是这是不可能的？

答案 1

您可以使用iText执行此操作。我用下面的代码测试了它。它在现有 PDF 的每一页上添加一大块文本和一个红色圆圈。

/* 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();

    }
}

答案 2

我修改了代码发现一点，它的工作原理如下

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();
}

}