java 未找到 PDF 标题签名
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提问by Nitesh Virani
I have below iTextpdf creation code, basically I need PdfStamperin my later part of code to render html content but it is throwing exception InvalidPdfExceptionwhile creating PdfStamper:
我有以下iTextpdf 创建代码，基本上我需要PdfStamper在我后面的代码部分来呈现 html 内容，但它InvalidPdfException在创建时抛出异常PdfStamper：
public static void main(String[] args) throws IOException, DocumentException {
String TEMP_PDF = "temp.pdf";
String RESULT = "output1.pdf";
OutputStream osTemp = null;
OutputStream osResult = null;
PdfWriter writer = null;
PdfReader reader=null;
PdfStamper stamper=null;
Document document = new Document(PageSize.LETTER);
try {
osTemp = new FileOutputStream(TEMP_PDF);
osResult = new FileOutputStream(RESULT);
writer = PdfWriter.getInstance(document, osTemp);
reader = new PdfReader(TEMP_PDF);
stamper = new PdfStamper(reader, osResult);
} catch (Exception e) {
e.printStackTrace();
} finally {
osTemp.close();
osResult.close();
writer.close();
reader.close();
stamper.close();
}
}
EDIT:
编辑：
public void createPdf(String file) throws DocumentException, IOException {
Document document = new Document(PageSize.LETTER);
PdfWriter pdfWriter = PdfWriter.getInstance(document, new FileOutputStream(file));
document.open();
int[] coords = new int[] {1, 50, 50, 100, 100} ;
PdfContentByte canvas = pdfWriter.getDirectContent();
ColumnText columnText = new ColumnText(canvas);
String css = "";
//llx, lly, urx, ury
columnText.setSimpleColumn(coords[1], coords[2], coords[3], coords[4]);
ElementList elements = XMLWorkerHelper.parseToElementList("<html><body><b>Bold text</b></body></html>", css);
for (Element element : elements) {
columnText.addElement(element);
}
columnText.go();
document.close();
}
回答by Bruno Lowagie
You have two problems:
你有两个问题：
Problem 1:
问题1：
PdfReadercan only read real PDF files. Those are files that start with %PDF-1and end with %%EOF. In your case, you don't have such a file. You are reading TEMP_PDFwhich is a file with 0 bytes. In iText, you create a PDF file in 5 steps. You only have step 1 (creating the document) and step 2 (creating the writer) of the creating process. You are missing steps 3 (opening the document), 4 (adding content) and 5 (closing the document).
PdfReader只能阅读真正的PDF文件。这些是以 . 开头%PDF-1和结尾的文件%%EOF。在您的情况下，您没有这样的文件。您正在阅读TEMP_PDF这是一个 0 字节的文件。在 iText 中，您可以通过 5 个步骤创建 PDF 文件。您只有创建过程的第 1 步（创建文档）和第 2 步（创建作者）。您缺少步骤 3（打开文档）、4（添加内容）和 5（关闭文档）。
You only have a complete PDF document after step 5. It is normal that you get an InvalidPdfExceptionas you aren't reading a complete PDF.
在第 5 步之后，您只有一个完整的 PDF 文档。InvalidPdfException因为您没有阅读完整的 PDF ，所以您得到一个是正常的。
Problem 2:
问题2：
You write: I need PdfStamperin my later part of code to render HTML content.
你写：我需要PdfStamper在我后面的代码部分呈现 HTML 内容。
This is wrong. PdfStamperis a class that can be used to stamp new content (a watermark, form field values, a header, a footer) on an existing PDF document. In no way does PdfStamperconvert PDF to HTML or render PDF as HTML.
这是错误的。PdfStamper是一个类，可用于在现有 PDF 文档上标记新内容（水印、表单字段值、页眉、页脚）。绝不PdfStamper会将 PDF 转换为 HTML 或将 PDF 呈现为 HTML。
