flatten (#1167)

src/main/java/stirling/software/SPDF/controller/api/misc/FlattenController.java

@@ -0,0 +1,84 @@
+package stirling.software.SPDF.controller.api.misc;
+
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+
+import org.apache.pdfbox.Loader;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDPageContentStream;
+import org.apache.pdfbox.pdmodel.graphics.image.JPEGFactory;
+import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
+import org.apache.pdfbox.pdmodel.interactive.form.PDAcroForm;
+import org.apache.pdfbox.rendering.ImageType;
+import org.apache.pdfbox.rendering.PDFRenderer;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ModelAttribute;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.multipart.MultipartFile;
+
+import io.github.pixee.security.Filenames;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import stirling.software.SPDF.model.PdfMetadata;
+import stirling.software.SPDF.model.api.misc.FlattenRequest;
+import stirling.software.SPDF.utils.PdfUtils;
+import stirling.software.SPDF.utils.WebResponseUtils;
+
+@RestController
+@RequestMapping("/api/v1/misc")
+@Tag(name = "Misc", description = "Miscellaneous APIs")
+public class FlattenController {
+
+    @PostMapping(consumes = "multipart/form-data", value = "/flatten")
+    @Operation(
+            summary = "Flatten PDF form fields or full page",
+            description =
+                    "Flattening just PDF form fields or converting each page to images to make text unselectable. Input: PDF, Output: PDF. Type: SISO")
+    public ResponseEntity<byte[]> flatten(@ModelAttribute FlattenRequest request) throws Exception {
+        MultipartFile file = request.getFileInput();
+
+        PDDocument document = Loader.loadPDF(file.getBytes());
+        PdfMetadata metadata = PdfUtils.extractMetadataFromPdf(document);
+        Boolean flattenOnlyForms = request.getFlattenOnlyForms();
+
+        if (Boolean.TRUE.equals(flattenOnlyForms)) {
+            PDAcroForm acroForm = document.getDocumentCatalog().getAcroForm();
+            if (acroForm != null) {
+                acroForm.flatten();
+            }
+            return WebResponseUtils.pdfDocToWebResponse(
+                    document, Filenames.toSimpleFileName(file.getOriginalFilename()));
+        } else {
+            // flatten whole page aka convert each page to image and readd it (making text
+            // unselectable)
+            PDFRenderer pdfRenderer = new PDFRenderer(document);
+            PDDocument newDocument = new PDDocument();
+            int numPages = document.getNumberOfPages();
+            for (int i = 0; i < numPages; i++) {
+                try {
+                    BufferedImage image = pdfRenderer.renderImageWithDPI(i, 300, ImageType.RGB);
+                    PDPage page = new PDPage();
+                    page.setMediaBox(document.getPage(i).getMediaBox());
+                    newDocument.addPage(page);
+                    try (PDPageContentStream contentStream =
+                            new PDPageContentStream(newDocument, page)) {
+                        PDImageXObject pdImage = JPEGFactory.createFromImage(newDocument, image);
+                        float pageWidth = page.getMediaBox().getWidth();
+                        float pageHeight = page.getMediaBox().getHeight();
+
+                        contentStream.drawImage(pdImage, 0, 0, pageWidth, pageHeight);
+                    }
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+            PdfUtils.setMetadataToPdf(newDocument, metadata);
+            return WebResponseUtils.pdfDocToWebResponse(
+                    newDocument, Filenames.toSimpleFileName(file.getOriginalFilename()));
+        }
+    }
+}