java压缩图片质量

可以使用Java的javax.imageio包中的ImageWriter来压缩图片质量。下面是一个简单的示例代码：

import javax.imageio.ImageIO;
import javax.imageio.ImageWriter;
import javax.imageio.plugins.jpeg.JPEGImageWriteParam;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;

public class ImageCompressionExample {

    public static void compressImageQuality(File inputFile, File outputFile, float quality) throws IOException {
        BufferedImage image = ImageIO.read(inputFile);

        Iterator<ImageWriter> writers = ImageIO.getImageWritersByFormatName("jpeg");
        if (!writers.hasNext()) {
            throw new IllegalStateException("No writers found");
        }

        ImageWriter writer = writers.next();
        ImageWriteParam param = writer.getDefaultWriteParam();
        param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
        param.setCompressionQuality(quality);

        writer.setOutput(ImageIO.createImageOutputStream(outputFile));
        writer.write(null, new IIOImage(image, null, null), param);
        writer.dispose();
    }

    public static void main(String[] args) {
        try {
            File inputFile = new File("input.jpg");
            File outputFile = new File("output.jpg");

            // 压缩图片质量为0.5（50%）
            compressImageQuality(inputFile, outputFile, 0.5f);

            System.out.println("Image compression complete");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

上述代码将读取名为"input.jpg"的原始图片文件，并将压缩后的图像保存为"output.jpg"，压缩质量为0.5（50%）。你可以根据需要调整压缩质量的值来获得不同质量的图像。