java itextpdf5.5.6 删除水印

在 iText PDF 中删除水印有两种方法：

1. 通过遍历页面内容并删除水印。

PdfReader reader = new PdfReader(inputFilePath);
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(outputFilePath));
int pageCount = reader.getNumberOfPages();
for (int i = 1; i <= pageCount; i++) {
    PdfContentByte cb = stamper.getOverContent(i);
    List<PdfCleanUpLocation> cleanUpLocations = new ArrayList<>();
    cleanUpLocations.add(new PdfCleanUpLocation(i, new Rectangle(0, 0, 500, 500), BaseColor.WHITE));
    PdfCleanUpProcessor cleaner = new PdfCleanUpProcessor(cleanUpLocations, stamper);
    cleaner.cleanUp();
    cb.setLiteral("Q\nq");
}
stamper.close();
reader.close();

2. 通过使用 PdfCleanUpProcessor 删除水印。

PdfReader reader = new PdfReader(inputFilePath);
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(outputFilePath));
int pageCount = reader.getNumberOfPages();
List<PdfCleanUpLocation> cleanUpLocations = new ArrayList<>();
for (int i = 1; i <= pageCount; i++) {
    cleanUpLocations.add(new PdfCleanUpLocation(i, new Rectangle(0, 0, 500, 500), BaseColor.WHITE));
}
PdfCleanUpProcessor cleaner = new PdfCleanUpProcessor(cleanUpLocations, stamper);
cleaner.cleanUp();
stamper.close();
reader.close();

其中，`inputFilePath` 和 `outputFilePath` 分别是输入文件和输出文件的路径。需要注意的是，iText PDF 5.5.6 已经过时，建议使用最新版本的 iText。