JAVA图片压缩

可以将像素高的图片转成像素低的图片，同时图片清晰度会降低

jdk1.5之前的不支持PNG格式的图片，之后支持，下面先来一个传进文件传出文件方式的：

package com.oct.com;

import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageTypeSpecifier;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.plugins.jpeg.JPEGImageWriteParam;


/**
 * 图片压缩
 * @author hero
 *
 */
public class ImgCompress {

	public static void main(String[] args) {
		ImgCompress.compressPic("C:\\img.jpg", "d:\\xxx.jpg");
	}
	
	/**
	 * 图片压缩
	 * @param srcFilePath
	 * @param descFilePath
	 * @return
	 */
	public static boolean compressPic(String srcFilePath,String descFilePath){
		
		File file = null;
		BufferedImage src = null;
		FileOutputStream out = null;
		
		ImageWriter imgWriter;
		
		ImageWriteParam imgWriterParams;
		
		//指定写图片的方式为jpg
		imgWriter = ImageIO.getImageWritersByFormatName("jpg").next();
		
		/**
		 * 写参数
		 */
		imgWriterParams = new JPEGImageWriteParam(null);
		//要使用压缩，必须指定压缩方式为mode_ex...
		imgWriterParams.setCompressionMode(imgWriterParams.MODE_EXPLICIT);
		
		//这里指定压缩的程度，参数qulity是取值0~1范围内
		imgWriterParams.setCompressionQuality((float)0.1);
		imgWriterParams.setProgressiveMode(imgWriterParams.MODE_DISABLED);
		ColorModel colorModel = ColorModel.getRGBdefault();
		//指定压缩时使用的彩色模式
		imgWriterParams.setDestinationType(new ImageTypeSpecifier(colorModel,
				colorModel.createCompatibleSampleModel(16, 16)));
		try {
			
			if(!ImgCompress.isBlanck(srcFilePath)){
				return false;
			}else{
				
				file = new File(srcFilePath);
				src = ImageIO.read(file);//缓存图片
				out = new FileOutputStream(descFilePath);//文件输出流
				
				imgWriter.reset();
				
				//必须先指定out值，才能调用write方法，ImageOutputStream可以通过任何
				//OutputStream
				imgWriter.setOutput(ImageIO.createImageOutputStream(out));
				
				imgWriter.write(null,new IIOImage(src, null, null),imgWriterParams);
				out.flush();
				out.close();
			}
		} catch (IOException e) {
			e.printStackTrace();
			return false;
		}
		return true;
	}
	
	private static boolean isBlanck(String imgPath){	
		File file = new File(imgPath);
		return file.exists();
	}
}