new features

src/main/java/stirling/software/SPDF/controller/api/ToSinglePageController.java

@@ -0,0 +1,86 @@
+package stirling.software.SPDF.controller.api;
+
+import java.io.IOException;
+import java.io.ByteArrayOutputStream;
+import com.itextpdf.kernel.pdf.*;
+import com.itextpdf.kernel.pdf.xobject.PdfFormXObject;
+import com.itextpdf.kernel.geom.PageSize;
+import com.itextpdf.kernel.geom.Rectangle;
+import com.itextpdf.layout.Document;
+import com.itextpdf.layout.element.Image;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDPageTree;
+import org.apache.pdfbox.pdmodel.common.PDRectangle;
+import org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+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 io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import stirling.software.SPDF.utils.WebResponseUtils;
+import org.apache.pdfbox.pdmodel.*;
+import org.apache.pdfbox.multipdf.PDFMergerUtility;
+@RestController
+@Tag(name = "General", description = "General APIs")
+public class ToSinglePageController {
+
+    private static final Logger logger = LoggerFactory.getLogger(ToSinglePageController.class);
+
+   
+    @PostMapping(consumes = "multipart/form-data", value = "/pdf-to-single-page")
+    @Operation(
+        summary = "Convert a multi-page PDF into a single long page PDF",
+        description = "This endpoint converts a multi-page PDF document into a single paged PDF document. The width of the single page will be same as the input's width, but the height will be the sum of all the pages' heights. Input:PDF Output:PDF Type:SISO"
+    )
+    public ResponseEntity<byte[]> pdfToSinglePage(
+        @RequestPart(required = true, value = "fileInput")
+        @Parameter(description = "The input multi-page PDF file to be converted into a single page", required = true)
+            MultipartFile file) throws IOException {
+
+        PdfReader reader = new PdfReader(file.getInputStream());
+        PdfDocument sourceDocument = new PdfDocument(reader);
+        
+        float totalHeight = 0;
+        float width = 0;
+
+        for (int i = 1; i <= sourceDocument.getNumberOfPages(); i++) {
+            Rectangle pageSize = sourceDocument.getPage(i).getPageSize();
+            totalHeight += pageSize.getHeight();
+            if(width < pageSize.getWidth())
+            	width = pageSize.getWidth();
+        }
+
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        PdfWriter writer = new PdfWriter(baos);
+        PdfDocument newDocument = new PdfDocument(writer);
+        PageSize newPageSize = new PageSize(width, totalHeight);
+        newDocument.addNewPage(newPageSize);
+
+        Document layoutDoc = new Document(newDocument);
+        float yOffset = totalHeight;
+
+        for (int i = 1; i <= sourceDocument.getNumberOfPages(); i++) {
+            PdfFormXObject pageCopy = sourceDocument.getPage(i).copyAsFormXObject(newDocument);
+            Image copiedPage = new Image(pageCopy);
+            copiedPage.setFixedPosition(0, yOffset - sourceDocument.getPage(i).getPageSize().getHeight());
+            yOffset -= sourceDocument.getPage(i).getPageSize().getHeight();
+            layoutDoc.add(copiedPage);
+        }
+
+        layoutDoc.close();
+        sourceDocument.close();
+
+        byte[] result = baos.toByteArray();
+        return WebResponseUtils.bytesToWebResponse(result, file.getOriginalFilename().replaceFirst("[.][^.]+$", "") + "_singlePage.pdf");
+    }
+}