为何无法正确使用iText7中的Document类？技术咨询

Let’s get to the bottom of this issue—you’re running into two main problems here that are causing the error: incorrect syntax when creating the Document instance, and importing the wrong Document class entirely. Here’s how to fix both:

1. Correct the Document Instantiation Syntax #

Your line Document doc = new Document; has two critical issues:

• It’s missing parentheses for the constructor call
• It’s missing the required PdfDocument parameter that links your layout Document to the underlying PDF structure

Fix it to this:

Document doc = new Document(pdfDocument);

2. Import the Right Document Class #

The static import import static com.itextpdf.kernel.pdf.PdfName.Document; is pulling in a PDF internal name constant, not the layout Document class you need for building content. Replace that incorrect import with the correct one:

import com.itextpdf.layout.Document;

3. Double-Check Your Dependencies (If Issues Persist) #

If you’re still seeing problems after fixing the above, make sure you have the full iText7 core dependencies installed. The Document class lives in the layout module, so if you’re using a build tool:

• For Maven, add this to your pom.xml:

  <dependency>
      <groupId>com.itextpdf</groupId>
      <artifactId>itext7-core</artifactId>
      <version>7.2.5</version> <!-- Use the latest stable version available -->
      <type>pom</type>
  </dependency>
  

• For Gradle, add this to your build script:

  implementation 'com.itextpdf:itext7-core:7.2.5'
  

Full Working Example #

Here’s your code corrected end-to-end, including a valid file path and basic content addition:

import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Paragraph;
import java.io.File;
import java.io.IOException;

public class CreatePdf {
    public static void main(String[] args) throws IOException {
        // Use a valid path with a filename (not just a directory)
        File file = new File("D:/project/my_output.pdf");
        PdfWriter writer = new PdfWriter(file);
        PdfDocument pdfDocument = new PdfDocument(writer);
        Document doc = new Document(pdfDocument);
        
        // Add sample content to the document
        doc.add(new Paragraph("Success! Your iText7 Document is working."));
        
        // Always close the document and PdfDocument to flush content
        doc.close();
        pdfDocument.close();
    }
}

A quick note: your original file path D/project is missing a slash and a filename—make sure you point to a specific .pdf file, not just a directory, to avoid file access errors.

内容的提问来源于stack exchange，提问作者Szabolcs Fekete