如何在春季启动时减小PNG/JPEG文件大小

Question

我想在保存图像时减小文件大小。请把这个代码作为参考。以及如何减小文件大小

public void saveImage(MultipartFile image_one, MultipartFile image_two, MultipartFile image_three) throws Exception{
System.out.println("Inside Save image Repo");

String folder = "C:/Users/HP/Photos";
byte[] bytes_one;
try {
bytes_one = image_one.getBytes();

Path path1 = Paths.get(folder + image_one.getOriginalFilename()); 
System.out.println("Path of 1st imagae : "+path1);

Files.write(path1, bytes_one);

System.out.println("Image-1 size : "+bytes_one.length);
} catch (Exception e) {
System.out.println("Inside Catch Block -> Image not found ");
e.printStackTrace();
}   
}

Answer 1

您可以使用Javajavax.imageio库并使用函数来压缩图像字节。

这个应该可以完成工作:

public byte[] compressImage(MultipartFile image) throws IOException
{
InputStream inputStream = image.getInputStream();
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
float imageQuality = 0.3f;
// Create the buffered image
BufferedImage bufferedImage = ImageIO.read(inputStream);
// Get image writers
Iterator<ImageWriter> imageWriters = ImageIO.getImageWritersByFormatName("jpg"); // Input your Format Name here
if (!imageWriters.hasNext())
throw new IllegalStateException("Writers Not Found!!");
ImageWriter imageWriter = imageWriters.next();
ImageOutputStream imageOutputStream = ImageIO.createImageOutputStream(outputStream);
imageWriter.setOutput(imageOutputStream);
ImageWriteParam imageWriteParam = imageWriter.getDefaultWriteParam();
// Set the compress quality metrics
imageWriteParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
imageWriteParam.setCompressionQuality(imageQuality);
// Compress and insert the image into the byte array.
imageWriter.write(null, new IIOImage(bufferedImage, null, null), imageWriteParam);
byte[] imageBytes = outputStream.toByteArray();
// close all streams
inputStream.close();
outputStream.close();
imageOutputStream.close();
imageWriter.dispose();

return imageBytes;
}

它返回压缩图像bytes，因此返回的值可以转换为许多东西。在你的例子中，在一个文件中…

byte[] compressedImageBytes = compressImage(imageOne);
Files.write(path1, bytesOne);