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Stirling-PDF/src/main/java/stirling/software/SPDF/controller/api/misc/CompressController.java
Anthony Stirling 5f771b7851 formatting
2023-12-30 19:11:27 +00:00

270 lines
12 KiB
Java

package stirling.software.SPDF.controller.api.misc;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;
import org.apache.commons.io.FileUtils;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDResources;
import org.apache.pdfbox.pdmodel.graphics.PDXObject;
import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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.swagger.v3.oas.annotations.Operation;
import io.swagger.v3.oas.annotations.tags.Tag;
import stirling.software.SPDF.model.api.misc.OptimizePdfRequest;
import stirling.software.SPDF.utils.GeneralUtils;
import stirling.software.SPDF.utils.ProcessExecutor;
import stirling.software.SPDF.utils.ProcessExecutor.ProcessExecutorResult;
import stirling.software.SPDF.utils.WebResponseUtils;
@RestController
@RequestMapping("/api/v1/misc")
@Tag(name = "Misc", description = "Miscellaneous APIs")
public class CompressController {
private static final Logger logger = LoggerFactory.getLogger(CompressController.class);
@PostMapping(consumes = "multipart/form-data", value = "/compress-pdf")
@Operation(
summary = "Optimize PDF file",
description =
"This endpoint accepts a PDF file and optimizes it based on the provided parameters. Input:PDF Output:PDF Type:SISO")
public ResponseEntity<byte[]> optimizePdf(@ModelAttribute OptimizePdfRequest request)
throws Exception {
MultipartFile inputFile = request.getFileInput();
Integer optimizeLevel = request.getOptimizeLevel();
String expectedOutputSizeString = request.getExpectedOutputSize();
if (expectedOutputSizeString == null && optimizeLevel == null) {
throw new Exception("Both expected output size and optimize level are not specified");
}
Long expectedOutputSize = 0L;
boolean autoMode = false;
if (expectedOutputSizeString != null && expectedOutputSizeString.length() > 1) {
expectedOutputSize = GeneralUtils.convertSizeToBytes(expectedOutputSizeString);
autoMode = true;
}
// Save the uploaded file to a temporary location
Path tempInputFile = Files.createTempFile("input_", ".pdf");
inputFile.transferTo(tempInputFile.toFile());
long inputFileSize = Files.size(tempInputFile);
// Prepare the output file path
Path tempOutputFile = Files.createTempFile("output_", ".pdf");
// Determine initial optimization level based on expected size reduction, only if in
// autoMode
if (autoMode) {
double sizeReductionRatio = expectedOutputSize / (double) inputFileSize;
if (sizeReductionRatio > 0.7) {
optimizeLevel = 1;
} else if (sizeReductionRatio > 0.5) {
optimizeLevel = 2;
} else if (sizeReductionRatio > 0.35) {
optimizeLevel = 3;
} else {
optimizeLevel = 3;
}
}
boolean sizeMet = false;
while (!sizeMet && optimizeLevel <= 4) {
// Prepare the Ghostscript command
List<String> command = new ArrayList<>();
command.add("gs");
command.add("-sDEVICE=pdfwrite");
command.add("-dCompatibilityLevel=1.4");
switch (optimizeLevel) {
case 1:
command.add("-dPDFSETTINGS=/prepress");
break;
case 2:
command.add("-dPDFSETTINGS=/printer");
break;
case 3:
command.add("-dPDFSETTINGS=/ebook");
break;
case 4:
command.add("-dPDFSETTINGS=/screen");
break;
default:
command.add("-dPDFSETTINGS=/default");
}
command.add("-dNOPAUSE");
command.add("-dQUIET");
command.add("-dBATCH");
command.add("-sOutputFile=" + tempOutputFile.toString());
command.add(tempInputFile.toString());
ProcessExecutorResult returnCode =
ProcessExecutor.getInstance(ProcessExecutor.Processes.GHOSTSCRIPT)
.runCommandWithOutputHandling(command);
// Check if file size is within expected size or not auto mode so instantly finish
long outputFileSize = Files.size(tempOutputFile);
if (outputFileSize <= expectedOutputSize || !autoMode) {
sizeMet = true;
} else {
// Increase optimization level for next iteration
optimizeLevel++;
if (autoMode && optimizeLevel > 3) {
System.out.println("Skipping level 4 due to bad results in auto mode");
sizeMet = true;
} else if (optimizeLevel == 5) {
} else {
System.out.println(
"Increasing ghostscript optimisation level to " + optimizeLevel);
}
}
}
if (expectedOutputSize != null && autoMode) {
long outputFileSize = Files.size(tempOutputFile);
if (outputFileSize > expectedOutputSize) {
try (PDDocument doc = PDDocument.load(new File(tempOutputFile.toString()))) {
long previousFileSize = 0;
double scaleFactor = 1.0;
while (true) {
for (PDPage page : doc.getPages()) {
PDResources res = page.getResources();
for (COSName name : res.getXObjectNames()) {
PDXObject xobj = res.getXObject(name);
if (xobj instanceof PDImageXObject) {
PDImageXObject image = (PDImageXObject) xobj;
// Get the image in BufferedImage format
BufferedImage bufferedImage = image.getImage();
// Calculate the new dimensions
int newWidth = (int) (bufferedImage.getWidth() * scaleFactor);
int newHeight = (int) (bufferedImage.getHeight() * scaleFactor);
// If the new dimensions are zero, skip this iteration
if (newWidth == 0 || newHeight == 0) {
continue;
}
// Otherwise, proceed with the scaling
Image scaledImage =
bufferedImage.getScaledInstance(
newWidth, newHeight, Image.SCALE_SMOOTH);
// Convert the scaled image back to a BufferedImage
BufferedImage scaledBufferedImage =
new BufferedImage(
newWidth,
newHeight,
BufferedImage.TYPE_INT_RGB);
scaledBufferedImage
.getGraphics()
.drawImage(scaledImage, 0, 0, null);
// Compress the scaled image
ByteArrayOutputStream compressedImageStream =
new ByteArrayOutputStream();
ImageIO.write(
scaledBufferedImage, "jpeg", compressedImageStream);
byte[] imageBytes = compressedImageStream.toByteArray();
compressedImageStream.close();
// Convert compressed image back to PDImageXObject
ByteArrayInputStream bais =
new ByteArrayInputStream(imageBytes);
PDImageXObject compressedImage =
PDImageXObject.createFromByteArray(
doc,
imageBytes,
image.getCOSObject().toString());
// Replace the image in the resources with the compressed
// version
res.put(name, compressedImage);
}
}
}
// save the document to tempOutputFile again
doc.save(tempOutputFile.toString());
long currentSize = Files.size(tempOutputFile);
// Check if the overall PDF size is still larger than expectedOutputSize
if (currentSize > expectedOutputSize) {
// Log the current file size and scaleFactor
System.out.println(
"Current file size: "
+ FileUtils.byteCountToDisplaySize(currentSize));
System.out.println("Current scale factor: " + scaleFactor);
// The file is still too large, reduce scaleFactor and try again
scaleFactor *= 0.9; // reduce scaleFactor by 10%
// Avoid scaleFactor being too small, causing the image to shrink to 0
if (scaleFactor < 0.2 || previousFileSize == currentSize) {
throw new RuntimeException(
"Could not reach the desired size without excessively degrading image quality, lowest size recommended is "
+ FileUtils.byteCountToDisplaySize(currentSize)
+ ", "
+ currentSize
+ " bytes");
}
previousFileSize = currentSize;
} else {
// The file is small enough, break the loop
break;
}
}
}
}
}
// Read the optimized PDF file
byte[] pdfBytes = Files.readAllBytes(tempOutputFile);
// Check if optimized file is larger than the original
if (pdfBytes.length > inputFileSize) {
// Log the occurrence
logger.warn(
"Optimized file is larger than the original. Returning the original file instead.");
// Read the original file again
pdfBytes = Files.readAllBytes(tempInputFile);
}
// Clean up the temporary files
Files.delete(tempInputFile);
Files.delete(tempOutputFile);
// Return the optimized PDF as a response
String outputFilename =
inputFile.getOriginalFilename().replaceFirst("[.][^.]+$", "") + "_Optimized.pdf";
return WebResponseUtils.bytesToWebResponse(pdfBytes, outputFilename);
}
}