PDF security features (#26)

- Support for adding and removing passwords
- Support for watermarks
- Dedicated page remover
- Support for PDF permissions
- Removed endpoint /home and replaced with /
- Code cleanups
- Fixed page titles

src/main/java/stirling/software/SPDF/controller/MergeController.java

@@ -0,0 +1,77 @@
+package stirling.software.SPDF.controller;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+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.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.core.io.InputStreamResource;
+import org.springframework.http.MediaType;
+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;
+
+@Controller
+public class MergeController {
+
+	private static final Logger logger = LoggerFactory.getLogger(MergeController.class);
+
+	@GetMapping("/merge-pdfs")
+	public String hello(Model model) {
+		model.addAttribute("currentPage", "merge-pdfs");
+		return "merge-pdfs";
+	}
+
+	@PostMapping("/merge-pdfs")
+	public ResponseEntity<InputStreamResource> mergePdfs(@RequestParam("fileInput") MultipartFile[] files)
+			throws IOException {
+		// Read the input PDF files into PDDocument objects
+		List<PDDocument> documents = new ArrayList<>();
+
+		// Loop through the files array and read each file into a PDDocument
+		for (MultipartFile file : files) {
+			documents.add(PDDocument.load(file.getInputStream()));
+		}
+
+		PDDocument mergedDoc = mergeDocuments(documents);
+		ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
+		mergedDoc.save(byteArrayOutputStream);
+		mergedDoc.close();
+
+		// Create an InputStreamResource from the merged PDF
+		InputStreamResource resource = new InputStreamResource(
+				new ByteArrayInputStream(byteArrayOutputStream.toByteArray()));
+
+		// Return the merged PDF as a response
+		return ResponseEntity.ok().contentType(MediaType.APPLICATION_PDF).body(resource);
+	}
+
+	private PDDocument mergeDocuments(List<PDDocument> documents) throws IOException {
+		// Create a new empty document
+		PDDocument mergedDoc = new PDDocument();
+
+		// Iterate over the list of documents and add their pages to the merged document
+		for (PDDocument doc : documents) {
+			// Get all pages from the current document
+			PDPageTree pages = doc.getPages();
+			// Iterate over the pages and add them to the merged document
+			for (PDPage page : pages) {
+				mergedDoc.addPage(page);
+			}
+		}
+
+		// Return the merged document
+		return mergedDoc;
+	}
+
+}