使用java来压缩图片

使用java来压缩图片，简单几句，清清爽爽

使用0.3的压缩比得到的结果如下（从2.8M压缩到268K，且图片的清晰度看不出明显差别）：

package carlspringtest;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Iterator;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.stream.ImageOutputStream;

/**
 * Compress JPEG File Example
 *
 * @author Krishna
 *
 */
public class CompressJPEGFileExample {
    public static void main(String[] args) throws FileNotFoundException, IOException{
        File imageFile = new File("f:\\IMG_20151219_172146.jpg");//source
        File compressedImageFile = new File("f:\\compressed_file5.jpg");//result

        InputStream inputStream = new FileInputStream(imageFile);
        OutputStream outputStream = new FileOutputStream(compressedImageFile);

        float imageQuality = 0.3f;

        //Create the buffered image
        BufferedImage bufferedImage = ImageIO.read(inputStream);

        //Get image writers
        Iterator<ImageWriter> imageWriters = ImageIO.getImageWritersByFormatName("jpg");

        if (!imageWriters.hasNext())
            throw new IllegalStateException("Writers Not Found!!");

        ImageWriter 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);

        //Created image
        imageWriter.write(null, new IIOImage(bufferedImage, null, null), imageWriteParam);

        // close all streams
        inputStream.close();
        outputStream.close();
        imageOutputStream.close();
        imageWriter.dispose();
    }
}