Stirling-PDF/src/main/java/stirling/software/SPDF/service/PdfImageRemovalService.java
PingLin8888 fa0152aa2d
Fix ConcurrentModificationException by modifying resources outside the iteration. (#1719)
Fix ConcurrentModificationException by collecting XObject names

- Changed  to use a list to collect XObject names before removal.
- Avoids ConcurrentModificationException by modifying resources outside the iteration.

Co-authored-by: Anthony Stirling <77850077+Frooodle@users.noreply.github.com>
2024-08-19 19:42:55 +01:00

52 lines
1.9 KiB
Java

package stirling.software.SPDF.service;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDResources;
import org.apache.pdfbox.pdmodel.graphics.PDXObject;
import org.springframework.stereotype.Service;
/** Service class responsible for removing image objects from a PDF document. */
@Service
public class PdfImageRemovalService {
/**
* Removes all image objects from the provided PDF document.
*
* <p>This method iterates over each page in the document and removes any image XObjects found
* in the page's resources.
*
* @param document The PDF document from which images will be removed.
* @return The modified PDF document with images removed.
* @throws IOException If an error occurs while processing the PDF document.
*/
public PDDocument removeImagesFromPdf(PDDocument document) throws IOException {
// Iterate over each page in the PDF document
for (PDPage page : document.getPages()) {
PDResources resources = page.getResources();
// Collect the XObject names to remove
List<COSName> namesToRemove = new ArrayList<>();
// Iterate over all XObject names in the page's resources
for (COSName name : resources.getXObjectNames()) {
// Check if the XObject is an image
if (resources.isImageXObject(name)) {
// Collect the name for removal
namesToRemove.add(name);
}
}
// Now, modify the resources by removing the collected names
for (COSName name : namesToRemove) {
resources.put(name, (PDXObject) null);
}
}
return document;
}
}