migrate exportUpdatedPages from bytes to stream (Stirling-Tools#6201)

Co-authored-by: ConnorYoh <40631091+ConnorYoh@users.noreply.github.com>

Author: Frooodle

app/core/src/main/java/stirling/software/SPDF/controller/api/converters/ConvertPdfJsonController.java

@@ -184,8 +184,6 @@ public ResponseEntity<Resource> exportPartialPdf(
 
         validateJobAccess(jobId);
 
-        byte[] pdfBytes = pdfJsonConversionService.exportUpdatedPages(jobId, document);
-
         String baseName =
                 (filename != null && !filename.isBlank())
                         ? FILE_EXTENSION_PATTERN
@@ -197,13 +195,18 @@ public ResponseEntity<Resource> exportPartialPdf(
                                 .orElse("document");
         String docName = baseName.endsWith(".pdf") ? baseName : baseName + ".pdf";
         TempFile tempOut = tempFileManager.createManagedTempFile(".pdf");
+        try (OutputStream os = Files.newOutputStream(tempOut.getPath())) {
+            pdfJsonConversionService.exportUpdatedPages(jobId, document, os);
+        } catch (Exception e) {
+            tempOut.close();
+            throw e;
+        }
         try {
-            Files.write(tempOut.getPath(), pdfBytes);
+            return WebResponseUtils.pdfFileToWebResponse(tempOut, docName);
         } catch (Exception e) {
             tempOut.close();
             throw e;
         }
-        return WebResponseUtils.pdfFileToWebResponse(tempOut, docName);
     }
 
     @GetMapping(value = "/pdf/text-editor/page/{jobId}/{pageNumber}")

app/core/src/main/java/stirling/software/SPDF/service/PdfJsonConversionService.java

@@ -6490,7 +6490,8 @@ public void extractPageFonts(String jobId, int pageNumber, OutputStream out)
         objectMapper.writeValue(out, pageFonts);
     }
 
-    public byte[] exportUpdatedPages(String jobId, PdfJsonDocument updates) throws IOException {
+    public void exportUpdatedPages(String jobId, PdfJsonDocument updates, OutputStream outputStream)
+            throws IOException {
         if (jobId == null || jobId.isBlank()) {
             throw new IllegalArgumentException("jobId is required for incremental export");
         }
@@ -6513,7 +6514,8 @@ public byte[] exportUpdatedPages(String jobId, PdfJsonDocument updates) throws I
             log.debug(
                     "Incremental export requested with no page updates; returning cached PDF for jobId {}",
                     jobId);
-            return cached.getPdfBytes();
+            outputStream.write(cached.getPdfBytes());
+            return;
         }
 
         try (PDDocument document = pdfDocumentFactory.load(cached.getPdfBytes(), true)) {
@@ -6580,7 +6582,8 @@ public byte[] exportUpdatedPages(String jobId, PdfJsonDocument updates) throws I
                 log.debug(
                         "Incremental export for jobId {} resulted in no page updates; returning cached PDF",
                         jobId);
-                return cached.getPdfBytes();
+                outputStream.write(cached.getPdfBytes());
+                return;
             }
 
             ByteArrayOutputStream baos = new ByteArrayOutputStream();
@@ -6603,7 +6606,7 @@ public byte[] exportUpdatedPages(String jobId, PdfJsonDocument updates) throws I
                     "Incremental export complete for jobId {} (pages updated: {})",
                     jobId,
                     updatedPages.stream().map(i -> i + 1).sorted().toList());
-            return updatedBytes;
+            outputStream.write(updatedBytes);
         }
     }