图片放缩

最近由于硬盘太小，数码照片太多，占了太多空间，写一个批量放缩照片的类！

package com.my.test.image;

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class ImageTool {
	private Boolean proportion=true;
	private List fileInList=new ArrayList();
	private List fileOutList=new ArrayList();
	public Boolean photojob(String inputdir,String outputdir,double bl){
		if(!check(inputdir,outputdir,bl)){
			return false;
		}
		for(int i=0;i<fileInList.size();i++){
			start((String)fileInList.get(i),(String)fileOutList.get(i),bl);
		}
		
		return true;
	}
	
	
	public Boolean start(String in,String out,double bl){
    	//建立输出文件对象
        File file = new File(out);
        FileOutputStream tempout = null;
        try {
            tempout = new FileOutputStream(file);
        } catch (Exception ex) {
            System.out.println(ex.toString());
        }
        Image img = null;
        //用于操作windows的一些组件
        Toolkit tk = Toolkit.getDefaultToolkit();
        Applet app = new Applet();
        MediaTracker mt = new MediaTracker(app);
        try {
            img = tk.getImage(in);
            mt.addImage(img, 0);
            mt.waitForID(0);
        } catch (Exception e) {
            e.printStackTrace();
        }
        if (img.getWidth(null) == -1) {
            return false;
        } else {
            int new_w;
            int new_h;
            if (this.proportion == true) { //判断是否是等比缩放.
            	//为等比缩放计算输出的图片宽度及高度                
                new_w = (int) (((double) img.getWidth(null))*bl);
                new_h = (int) (((double) img.getHeight(null)) *bl);
            } else {
                new_w = 100; //输出的图片宽度
                new_h = 100; //输出的图片高度
            }
            BufferedImage buffImg = new BufferedImage(new_w, new_h,
                    BufferedImage.TYPE_INT_RGB);
            Graphics g = buffImg.createGraphics();
            g.setColor(Color.white);
            g.fillRect(0, 0, new_w, new_h);
            g.drawImage(img, 0, 0, new_w, new_h, null);
            g.dispose();
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(tempout);
            try {
                encoder.encode(buffImg);
                tempout.close();
            } catch (IOException ex) {
                System.out.println(ex.toString());
            }
        }		
		return true;
	}
	public Boolean check(String inputdir,String outputdir,double bl){
		//判断放缩比例
		if(!checkbl(bl)){
			return false;
		}
		//判断目录
		if(!checkFile( inputdir, outputdir)){
			return false;
		}			
		return true;
	}
	//判断目录是否存在,过滤文件名
	public Boolean checkFile(String inputdir,String outputdir){
		File file=null;
		File file1=null;
		try {
			file = new File(inputdir);
		} catch (NullPointerException e) {			
			return false;
		}
		try {
			file1 = new File(outputdir);
		} catch (NullPointerException e) {			
			return false;
		}
		
		if(file.exists()){			
			if(file.isFile()){
				fileInList.add(file.getParent()+"/"+file.getName());
				if(file1.isDirectory()){					
					fileOutList.add(outputdir+"/"+file.getName().split("\\.")[0]+"_out."+file.getName().split("\\.")[1]);
				}else if(file1.isFile()){
					fileOutList.add(file1.getParent()+"/"+file.getName().split("\\.")[0]+"_out."+file.getName().split("\\.")[1]);
				}
			}else if(file.isDirectory()){
				for(int i=0;i<file.list().length;i++){
					if(checkname(file.list()[i])){
						fileInList.add(file.getPath()+"/"+file.list()[i]);
						if(file1.isDirectory()){						
							fileOutList.add(outputdir+"/"+file.list()[i].split("\\.")[0]+"_out."+file.list()[i].split("\\.")[1]);
						}else if(file1.isFile()){
							fileOutList.add(file1.getParent()+"/"+file.list()[i].split("\\.")[0]+"_out."+file.list()[i].split("\\.")[1]);
						}
					}
				}
			}
		}else{
			return false;
		}
		return true;
	}
	//判断放缩比例
	public Boolean checkbl(double bl){
		if(bl<0){
			System.out.println("放缩比例必须大于零！");
			return false;
		}
		return true;
	}	
	//过滤扩展名
	public Boolean checkname(String name){
		if(name.split("\\.")[1].equals("jpg")){
			return true;
		}else if(name.split("\\.")[1].equals("bmp")){
			return true;
		}
		
		return false;
	}
	public static void main(String[] args) {
		ImageTool it=new ImageTool();
		String in="C:\\Documents and Settings\\All Users\\Documents\\My Pictures\\示例图片";
		String out="D:\\temp";
		it.photojob(in,out, 0.2);
		System.out.println("原文件：\n"+in);
		System.out.println("目标文件：\n"+out);
		System.out.println("放缩完毕！");
	}

}