Stirling-PDF/src/main/java/stirling/software/SPDF/controller/RotationController.java

package stirling.software.SPDF.controller;

import java.io.IOException;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageTree;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;

import stirling.software.SPDF.utils.PdfUtils;

@Controller
public class RotationController {

    private static final Logger logger = LoggerFactory.getLogger(RotationController.class);

    @PostMapping("/rotate-pdf")
    public ResponseEntity<byte[]> rotatePDF(@RequestParam("fileInput") MultipartFile pdfFile, @RequestParam("angle") Integer angle) throws IOException {

        // Load the PDF document
        PDDocument document = PDDocument.load(pdfFile.getBytes());

        // Get the list of pages in the document
        PDPageTree pages = document.getPages();

        for (PDPage page : pages) {
            page.setRotation(page.getRotation() + angle);
        }

        return PdfUtils.pdfDocToWebResponse(document, pdfFile.getOriginalFilename().replaceFirst("[.][^.]+$", "") + "_rotated.pdf");

    }

    @GetMapping("/rotate-pdf")
    public String rotatePdfForm(Model model) {
        model.addAttribute("currentPage", "rotate-pdf");
        return "rotate-pdf";
    }

}