java实现gui界面的文件复制

代码中含有注释
如果自己要写文件复制的代码，建议流程
1、写一个简单的程序完成文件复制
2、利用JProgressBar完成进度条的设置，以及进度条的刷新展示
3、gui界面的TtextArea以及button十分简单，不解释！你懂得！
4、将上述步骤串在一起就可，这里注意thread running不能一直跑，要留给程序一定的时间去检测copy，也就是thread running per 1000ms，时间太短或者说不设置的话会出问题的，自己去理解，不做过多解释

package homework;

import java.lang.*;
import java.awt.Button;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;

//@author=BUPT:huanglin
public class File_Copy extends Frame implements ActionListener{

public int rate = 0;
    String old_filepath;
    String new_filepath;
private JProgressBar pro = new JProgressBar();   
    JPanel frame;
    Button copy = new Button("COPY");
    JTextArea From_Path = new JTextArea("");
    JTextArea To_Path = new JTextArea("");

    Run A = new Run();
//__init()
    File_Copy(){

        frame = new JPanel();
        frame.setLayout(null);
//text
final JLabel j1 = new JLabel("From");
final JLabel j2 = new JLabel("To");

        j1.setBounds(0,0,100,100);
        From_Path.setBounds(100,40,300,40);
        j2.setBounds(0,100,100,100);
        To_Path.setBounds(100,140,300,40);
        copy.setBounds(400,100,80,40);
        pro.setBounds(50,200,400,40);

//pro.setBackground(Color.GREEN);
        pro.setStringPainted(true);

        copy.addActionListener(this);


        frame.add(j1); 
        frame.add(From_Path);
        frame.add(To_Path);
        frame.add(j2);
        frame.add(copy); 
        frame.add(pro);
this.add(frame);

        A.start();
    }



//file copy 
public void copy(){
try{
long bytesum = 0;
int byteread = 0 ;
            File old_file = new File(old_filepath);
if(old_file.exists()){
long filelength = old_file.length(); 
                System.out.println("old_file length"+filelength);
                InputStream in = new FileInputStream(old_filepath);
                OutputStream out = new FileOutputStream(new_filepath);
//copy 1024 byte per time
byte [] buff = new byte[1024];
while ((byteread =  in.read(buff))!=-1){
                    bytesum += byteread;
if (rate != Integer.parseInt(String.valueOf(bytesum*100/filelength))){
                        rate = Integer.parseInt(String.valueOf(bytesum*100/filelength));
                        pro.setValue(rate);
                    }

                    System.out.println("rate"+rate);
//System.out.println(bytesum);
//file copy or we can regard it as writing a new file
                    out.write(buff, 0, byteread);
                }

                in.close();
            }
else{
                System.out.println("Old_file open WRONG!!!!!1 ");
            }
            old_filepath = null;
            new_filepath = null;
            rate = 0;


        }
catch(Exception e){
            System.out.println("copy file wrong:"+e);
        }
    }



//action listener function
public void actionPerformed(ActionEvent e) {  
if(e.getSource()==copy){
            old_filepath = From_Path.getText();
            new_filepath = To_Path.getText();
            System.out.println(old_filepath);
        }
    }

//thread running per 1000ms
private class Run extends Thread{
public void run(){
//file copy test as follows
//String old_filepath = "C:/Users/huanglin/Pictures/Screenshots/屏幕截图.png";
//String new_filepath = "C:/Users/huanglin/Pictures/Screenshots/屏幕截图3.png";
while(true){
                System.out.println("thread running");
if(old_filepath!=null){
                    copy();
                }
try{
                    Thread.sleep(1000);
                }
catch(Exception e){
                    System.out.println(e);
                }
            }


        }
    }


public static void main(String[]args){

//setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        File_Copy test = new File_Copy();
//window closed,system exit or close
        test.addWindowListener(new WindowAdapter()  
              {  
public void windowClosing(WindowEvent e)  
               {  
                   System.exit(0);  
               }  

    });  
//window
        test.setBounds(0, 0, 500, 300);
        test.setVisible(true);  
        test.setLayout(null);  
        test.setResizable(false);  
    }


}