使用Java+PDFBox提取PDF文本时出现错误，请求技术协助

Hey there! Let's work through your PDF text extraction issue with PDFBox. I notice a couple of areas we can tweak in your setup and code to get things running smoothly.

First: Update Your PDFBox Dependency #

You're using version 2.0.4, which is quite outdated (released back in 2017). Newer versions fix tons of bugs and add better compatibility with modern PDFs. Let's upgrade to a recent stable version—here's what your Maven dependency should look like:

<dependencies>
    <dependency>
        <groupId>org.apache.pdfbox</groupId>
        <artifactId>pdfbox</artifactId>
        <version>2.0.33</version> <!-- Use the latest stable version available -->
    </dependency>
</dependencies>

Fix Your Extraction Code #

Your code snippet cuts off, but I can see you're using older classes like PDFParser and COSDocument—these are deprecated in PDFBox 2.x. The modern, simplified way to extract text uses PDDocument directly along with PDFTextStripper. Here's a complete, working example:

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.text.PDFTextStripper;
import java.io.File;
import java.io.IOException;

public class PDFTextExtractor {
    public static void main(String[] args) {
        String pdfFilePath = "path/to/your/target.pdf";
        
        try (PDDocument document = PDDocument.load(new File(pdfFilePath))) {
            // Handle encrypted PDFs first
            if (document.isEncrypted()) {
                // Try empty password first (common for view-only protected PDFs)
                document.decrypt("");
            }
            
            PDFTextStripper textStripper = new PDFTextStripper();
            String extractedText = textStripper.getText(document);
            
            System.out.println("Extracted Text:\n" + extractedText);
        } catch (IOException e) {
            e.printStackTrace();
            System.err.println("Error extracting text: " + e.getMessage());
        }
    }
}

Common Issues to Check If You Still Get Errors #

If you're still seeing problems after updating, here are some key things to verify:

• Corrupted PDF File: Test with a simple, known-working PDF (like a sample from Apache's official docs) to rule out a damaged file.
• File Permissions: Make sure your application has read access to the PDF file's path.
• Strongly Encrypted PDFs: If the empty password doesn't work, you'll need the correct user password to decrypt the document.
• Dependency Conflicts: Check your build file for other PDF-related libraries (like iText) that might clash with PDFBox.

内容的提问来源于stack exchange，提问作者Sveta Tulova