写了个仿文件夹显示图片

我是参照着文件夹显示图片来写的，但是唯一可悲的是效率较慢，希望大神看到我的博客可以给我些建议和方法，而且还有竖滚动栏没动态设置

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;

import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;


public class PictureList extends JFrame{
	private int sum = 0;
	public PictureList(){
		this.setSize(450, 400);//设置窗口的大小
		JPanel jp = new JPanel();
		//jp.setBackground(Color.lightGray);
		jp.setLayout(new FlowLayout(FlowLayout.LEFT));//左对齐
		JScrollPane jsp = new JScrollPane();
		//jsp.add(jp);
		//jsp.setLayout(null);
		File file =new File("E:\\after");
		String[] file1 = file.list();
		
		jp.setBackground(Color.white);
		sum += Math.ceil(file1.length*1.0/4)*100;//控制竖滚动条长度：得到个数/4，取上界
		jp.setPreferredSize(new Dimension(jsp.getWidth(),sum));//设置
		this.setLocationRelativeTo(null);
		//jp.setSize(400, 300);
		
		jsp.getViewport().add(jp);
		jsp.setVerticalScrollBarPolicy(JScrollPane.
	                VERTICAL_SCROLLBAR_AS_NEEDED);  //设置竖滚动条  需要时出现
		    
		jsp.setHorizontalScrollBarPolicy(JScrollPane.
		              HORIZONTAL_SCROLLBAR_NEVER);	//横滚动条，永远不出现
		
		this.getContentPane().add(jsp);
		
		
		
		try {
           
			for(int i=0;i95){//设置长宽
     			if(height >95){//长宽都比95大
     				if((width-95)>( height-95)){//判断长离95近还是宽离95近
     					height = height*95/width;
     					width =  95;
     					
     				}else{
     					width = width*95/height;
     					height = 95;
     				}
     			}else{//长比95大，宽比95小
     				height = height*95/width;
 					width =  95;
     			}
     		}else{
     			if(height<95){//长宽都比95小
     				if((95-width)> (95-height)){
     					height = height*95/width;
     					width =  95;
     				}else{
     					width = width*95/height;
     					height = 95;
     				}
     			}else{//长比95小，宽95大
     				width = width*95/height;
 					height = 95;
     			}
     		}
//System.out.println(width+"  "+height);
//			if(Math.max(Math.abs(width-95), Math.abs(height-95))>0){
//				
//			}
			
			icon.setImage(icon.getImage().getScaledInstance(width, height, Image.SCALE_DEFAULT));
		
			jb.setPreferredSize(new Dimension(95,95));
			jb.setBackground(Color.white);
			//jb.setBorder(null);
			jp.add(jb);
			}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
	}
	
}