java图片压缩到200K以内

ImageCompresser.java

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Date;
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;
import javax.imageio.stream.MemoryCacheImageOutputStream;

import org.apache.commons.io.FileUtils;

/**
 * @author Jeff.Chen
 *
 */
public class ImageCompresser {
	public static void main(String[] args) throws IOException {
		File input = new File("C:\\Users\\lenovo\\Pictures\\100708090966041.jpg");
	    
		long size = FileUtils.sizeOf(input);
		float compressRate = 200000.0f / size;
//		float compressRate = 0.5f;
		if (compressRate < 1.0) {
			System.out.println("文件大小：" + FileUtils.byteCountToDisplaySize(size));
			Date now = new Date();
			File compressedImageFile = new File("C:\\Users\\lenovo\\Pictures\\compress_"+ now.getSeconds() +".jpg");
		    OutputStream os =new FileOutputStream(compressedImageFile);
		    BufferedImage image = ImageIO.read(input);
			writeJPG(image, os, compressRate);
			long sz = FileUtils.sizeOf(compressedImageFile);
			System.out.println("文件大小：" + FileUtils.byteCountToDisplaySize(sz));
		}else {
			System.out.println("文件大小：" + FileUtils.byteCountToDisplaySize(size) + ", 无须压缩。");
		}
	}
	
	public static void writeJPG(
		    BufferedImage bufferedImage,
		    OutputStream outputStream,
		    float quality) throws IOException
		{
		    Iterator<ImageWriter> iterator =
		        ImageIO.getImageWritersByFormatName("jpg");
		    ImageWriter imageWriter = iterator.next();
		    ImageWriteParam imageWriteParam = imageWriter.getDefaultWriteParam();
		    imageWriteParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
		    imageWriteParam.setCompressionQuality(quality);
		    ImageOutputStream imageOutputStream =
		        new MemoryCacheImageOutputStream(outputStream);
		    imageWriter.setOutput(imageOutputStream);
		    IIOImage iioimage = new IIOImage(bufferedImage, null, null);
		    imageWriter.write(null, iioimage, imageWriteParam);
		    imageOutputStream.flush();
		}
}