update #5
1 changed files with 53 additions and 29 deletions
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@ -1,12 +1,12 @@
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package stirling.software.SPDF.controller.api.misc;
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package stirling.software.SPDF.controller.api.misc;
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import java.awt.image.BufferedImage;
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import java.awt.image.BufferedImage;
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import java.io.ByteArrayOutputStream;
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import java.io.IOException;
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import java.io.IOException;
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import java.util.ArrayList;
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import java.util.ArrayList;
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import java.util.Collections;
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import java.util.List;
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import java.util.List;
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import java.util.stream.Collectors;
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import java.util.zip.ZipEntry;
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import java.util.stream.IntStream;
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import java.util.zip.ZipOutputStream;
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import org.apache.pdfbox.Loader;
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import org.apache.pdfbox.Loader;
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import org.apache.pdfbox.pdmodel.PDDocument;
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import org.apache.pdfbox.pdmodel.PDDocument;
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@ -17,6 +17,7 @@ import org.apache.pdfbox.text.PDFTextStripper;
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import org.slf4j.Logger;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
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import org.slf4j.LoggerFactory;
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import org.springframework.http.HttpStatus;
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import org.springframework.http.HttpStatus;
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import org.springframework.http.MediaType;
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import org.springframework.http.ResponseEntity;
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import org.springframework.http.ResponseEntity;
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import org.springframework.web.bind.annotation.ModelAttribute;
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import org.springframework.web.bind.annotation.ModelAttribute;
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import org.springframework.web.bind.annotation.PostMapping;
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import org.springframework.web.bind.annotation.PostMapping;
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@ -50,31 +51,31 @@ public class BlankPageController {
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int threshold = request.getThreshold();
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int threshold = request.getThreshold();
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float whitePercent = request.getWhitePercent();
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float whitePercent = request.getWhitePercent();
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PDDocument document = null;
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try (PDDocument document = Loader.loadPDF(inputFile.getBytes())) {
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try {
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document = Loader.loadPDF(inputFile.getBytes());
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PDPageTree pages = document.getDocumentCatalog().getPages();
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PDPageTree pages = document.getDocumentCatalog().getPages();
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PDFTextStripper textStripper = new PDFTextStripper();
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PDFTextStripper textStripper = new PDFTextStripper();
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List<Integer> pagesToKeepIndex = new ArrayList<>();
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List<PDPage> nonBlankPages = new ArrayList<>();
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List<PDPage> blankPages = new ArrayList<>();
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int pageIndex = 0;
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int pageIndex = 0;
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PDFRenderer pdfRenderer = new PDFRenderer(document);
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PDFRenderer pdfRenderer = new PDFRenderer(document);
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pdfRenderer.setSubsamplingAllowed(true);
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pdfRenderer.setSubsamplingAllowed(true);
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for (PDPage page : pages) {
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for (PDPage page : pages) {
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logger.info("checking page " + pageIndex);
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logger.info("checking page {}", pageIndex);
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textStripper.setStartPage(pageIndex + 1);
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textStripper.setStartPage(pageIndex + 1);
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textStripper.setEndPage(pageIndex + 1);
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textStripper.setEndPage(pageIndex + 1);
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String pageText = textStripper.getText(document);
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String pageText = textStripper.getText(document);
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boolean hasText = !pageText.trim().isEmpty();
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boolean hasText = !pageText.trim().isEmpty();
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Boolean blank = true;
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boolean blank = true;
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if (hasText) {
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if (hasText) {
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logger.info("page " + pageIndex + " has text, not blank");
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logger.info("page {} has text, not blank", pageIndex);
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blank = false;
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blank = false;
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} else {
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} else {
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boolean hasImages = PdfUtils.hasImagesOnPage(page);
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boolean hasImages = PdfUtils.hasImagesOnPage(page);
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if (hasImages) {
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if (hasImages) {
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logger.info("page " + pageIndex + " has image, running blank detection");
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logger.info("page {} has image, running blank detection", pageIndex);
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// Render image and save as temp file
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// Render image and save as temp file
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BufferedImage image = pdfRenderer.renderImageWithDPI(pageIndex, 30);
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BufferedImage image = pdfRenderer.renderImageWithDPI(pageIndex, 30);
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blank = isBlankImage(image, threshold, whitePercent, threshold);
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blank = isBlankImage(image, threshold, whitePercent, threshold);
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@ -82,34 +83,57 @@ public class BlankPageController {
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}
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}
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if (blank) {
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if (blank) {
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logger.info("Skipping, Image was blank for page #" + pageIndex);
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logger.info("Skipping, Image was blank for page #{}", pageIndex);
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blankPages.add(page);
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} else {
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} else {
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logger.info("page " + pageIndex + " has image which is not blank");
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logger.info("page {} has image which is not blank", pageIndex);
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pagesToKeepIndex.add(pageIndex);
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nonBlankPages.add(page);
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}
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}
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pageIndex++;
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pageIndex++;
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}
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}
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// Remove pages not present in pagesToKeepIndex
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List<Integer> pageIndices =
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ByteArrayOutputStream baos = new ByteArrayOutputStream();
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IntStream.range(0, pages.getCount()).boxed().collect(Collectors.toList());
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ZipOutputStream zos = new ZipOutputStream(baos);
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Collections.reverse(pageIndices); // Reverse to prevent index shifting during removal
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for (Integer i : pageIndices) {
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String filename =
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if (!pagesToKeepIndex.contains(i)) {
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Filenames.toSimpleFileName(inputFile.getOriginalFilename())
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pages.remove(i);
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.replaceFirst("[.][^.]+$", "");
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}
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if (!nonBlankPages.isEmpty()) {
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createZipEntry(zos, nonBlankPages, filename + "_nonBlankPages.pdf");
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} else {
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createZipEntry(zos, blankPages, filename + "_allBlankPages.pdf");
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}
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}
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return WebResponseUtils.pdfDocToWebResponse(
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if (!nonBlankPages.isEmpty() && !blankPages.isEmpty()) {
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document,
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createZipEntry(zos, blankPages, filename + "_blankPages.pdf");
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Filenames.toSimpleFileName(inputFile.getOriginalFilename())
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}
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.replaceFirst("[.][^.]+$", "")
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+ "_blanksRemoved.pdf");
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zos.close();
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logger.info("Returning ZIP file: {}", filename + "_processed.zip");
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return WebResponseUtils.boasToWebResponse(
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baos, filename + "_processed.zip", MediaType.APPLICATION_OCTET_STREAM);
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} catch (IOException e) {
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} catch (IOException e) {
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logger.error("exception", e);
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logger.error("exception", e);
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return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
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return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
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} finally {
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}
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if (document != null) document.close();
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}
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public void createZipEntry(ZipOutputStream zos, List<PDPage> pages, String entryName)
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throws IOException {
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try (PDDocument document = new PDDocument()) {
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for (PDPage page : pages) {
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document.addPage(page);
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}
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ZipEntry zipEntry = new ZipEntry(entryName);
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zos.putNextEntry(zipEntry);
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document.save(zos);
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zos.closeEntry();
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}
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}
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}
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}
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