blank page test

src/main/java/stirling/software/SPDF/controller/api/other/BlankPageController.java

@@ -0,0 +1,98 @@
+package stirling.software.SPDF.controller.api.other;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDPageTree;
+import org.apache.pdfbox.text.PDFTextStripper;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestPart;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.multipart.MultipartFile;
+import stirling.software.SPDF.utils.ImageFinder;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+@RestController
+public class BlankPageController {
+
+    @PostMapping(consumes = "multipart/form-data", value = "/remove-blanks")
+    public ResponseEntity<byte[]> removeBlankPages(@RequestPart(required = true, value = "fileInput") MultipartFile inputFile, @RequestPart(required = true, value = "processType") int processType) throws IOException, InterruptedException {
+        boolean removeNoText = false;
+        boolean removeNoTextOrImages = false;
+        
+        if(processType == 0) {
+        	removeNoText = true;
+        } else if (processType == 1) {
+        	removeNoTextOrImages = true;
+        } else if (processType == 2) {
+        	//run OCR 
+        	OCRController ocr = new OCRController();
+            ocr.processPdfWithOCR(inputFile, Arrays.asList("eng"), false, false, true, false, "type", "hocr", false);
+            
+        	removeNoText = true;
+        }
+
+        try {
+            PDDocument document = PDDocument.load(inputFile.getInputStream());
+            PDPageTree pages = document.getDocumentCatalog().getPages();
+            PDFTextStripper textStripper = new PDFTextStripper();
+
+            List<PDPage> pagesToKeep = new ArrayList<>();
+            int pageIndex = 0;
+
+            for (PDPage page : pages) {
+                pageIndex++;
+                textStripper.setStartPage(pageIndex);
+                textStripper.setEndPage(pageIndex);
+                String pageText = textStripper.getText(document);
+                boolean hasText = !pageText.trim().isEmpty();
+                boolean hasImages = hasImagesOnPage(page);
+
+                if (removeNoText && removeNoTextOrImages) {
+                    if (hasText || hasImages) {
+                        pagesToKeep.add(page);
+                    }
+                } else if (removeNoText) {
+                    if (hasText) {
+                        pagesToKeep.add(page);
+                    }
+                } else if (removeNoTextOrImages) {
+                    if (hasText && hasImages) {
+                        pagesToKeep.add(page);
+                    }
+                } else {
+                    pagesToKeep.add(page);
+                }
+            }
+
+            PDDocument outputDocument = new PDDocument();
+            for (PDPage page : pagesToKeep) {
+                outputDocument.addPage(page);
+            }
+
+            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+            outputDocument.save(outputStream);
+            outputDocument.close();
+            document.close();
+
+            return new ResponseEntity<>(outputStream.toByteArray(), HttpStatus.OK);
+        } catch (IOException e) {
+            e.printStackTrace();
+            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
+        }
+    }
+    
+    private static boolean hasImagesOnPage(PDPage page) throws IOException {
+        ImageFinder imageFinder = new ImageFinder(page);
+        imageFinder.processPage(page);
+        return imageFinder.hasImages();
+    }
+    
+    
+
+    // ... rest of the code (ImageFinder class and hasImagesOnPage method)
+}

src/main/java/stirling/software/SPDF/utils/ImageFinder.java

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+package stirling.software.SPDF.utils;
+
+import org.apache.pdfbox.contentstream.operator.Operator;
+import org.apache.pdfbox.contentstream.operator.OperatorName;
+import org.apache.pdfbox.cos.COSBase;
+import org.apache.pdfbox.cos.COSName;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.graphics.PDXObject;
+import org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject;
+import org.apache.pdfbox.pdmodel.graphics.image.PDImage;
+import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
+
+import java.awt.geom.Point2D;
+import java.io.IOException;
+import java.util.List;
+
+public class ImageFinder extends org.apache.pdfbox.contentstream.PDFGraphicsStreamEngine {
+    private boolean hasImages = false;
+
+    public ImageFinder(PDPage page) {
+        super(page);
+    }
+
+    public boolean hasImages() {
+        return hasImages;
+    }
+
+    @Override
+    protected void processOperator(Operator operator, List<COSBase> operands) throws IOException {
+        String operation = operator.getName();
+        if (operation.equals(OperatorName.DRAW_OBJECT)) {
+            COSBase base = operands.get(0);
+            if (base instanceof COSName) {
+                COSName objectName = (COSName) base;
+                PDXObject xobject = getResources().getXObject(objectName);
+                if (xobject instanceof PDImageXObject) {
+                    hasImages = true;
+                } else if (xobject instanceof PDFormXObject) {
+                    PDFormXObject form = (PDFormXObject) xobject;
+                    ImageFinder innerFinder = new ImageFinder(getPage());
+                    innerFinder.processPage(getPage());
+                    if (innerFinder.hasImages()) {
+                        hasImages = true;
+                    }
+                }
+            }
+        }
+        super.processOperator(operator, operands);
+    }
+
+	@Override
+	public void appendRectangle(Point2D p0, Point2D p1, Point2D p2, Point2D p3) throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+	@Override
+	public void drawImage(PDImage pdImage) throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+	@Override
+	public void clip(int windingRule) throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+	@Override
+	public void moveTo(float x, float y) throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+	@Override
+	public void lineTo(float x, float y) throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+	@Override
+	public void curveTo(float x1, float y1, float x2, float y2, float x3, float y3) throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+	@Override
+	public Point2D getCurrentPoint() throws IOException {
+		// TODO Auto-generated method stub
+		return null;
+	}
+
+	@Override
+	public void closePath() throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+	@Override
+	public void endPath() throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+	@Override
+	public void strokePath() throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+	@Override
+	public void fillPath(int windingRule) throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+	@Override
+	public void fillAndStrokePath(int windingRule) throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+	@Override
+	public void shadingFill(COSName shadingName) throws IOException {
+		// TODO Auto-generated method stub
+		
+	}
+
+    // ... rest of the overridden methods
+}