求助大佬，请问这是什么情况？需要怎么改进？

package 传输图像;
import java.net.*;
import java.awt.*; 
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
class ImageCanvas extends Canvas {
	Image image=null;
	public ImageCanvas() {
		setSize(200,200);
	}
	public void paint(Graphics g) {
		if(image!=null)
			g.drawImage(image,0,0,this);
	}
	public void setImage(Image image) {
		this.image=image;
	}
}
public class ClientGetImage extends JFrame implements Runnable,ActionListener {
	JButton b=new JButton("获取图像");
	ImageCanvas canvas;
	ClientGetImage() {
		super("I am a client");
		setSize(320,200);
		setVisible(true);
		b.addActionListener(this);
		add(b,BorderLayout.NORTH);
		canvas=new ImageCanvas();
		add(canvas,BorderLayout.CENTER);
		Thread thread=new Thread(this);
		validate();
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		thread.start();
	}
	public void actionPerformed(ActionEvent event) {
		byte b[]="请发图像".trim().getBytes();			//trim() 方法用于删除字符串的头尾空白符。 getBytes()方法是得到一个操作系统默认的编码格式的字节数组。
		try{ InetAddress address=InetAddress.getByName("127.0.0.1");
		DatagramPacket data= new DatagramPacket(b,b.length,address,1234); //创建数据包 data，该数据包的目标地址和端口分别是
		//address和1234，其中的数据为数组b中的全部字节。
		DatagramSocket mailSend= new DatagramSocket(); //创建负责发送数据的 mailSend 对象。
		mailSend.send(data); //mailSend 发送数据 data。
		}
		catch(Exception e){}
	}
	public void run() {
		DatagramPacket pack=null;
		DatagramSocket mailReceive=null;		//接收数据包
		byte b[]=new byte[8192];
		ByteArrayOutputStream out=new ByteArrayOutputStream();			//字节数组输出流
		try{ pack=new DatagramPacket(b,b.length);
		mailReceive = new DatagramSocket(5678); //创建在端口 5678 负责收取数据包的 mailReceive 对象。
		}
		catch(Exception e){}
		try{ while(true){
			mailReceive.receive(pack);
			String message=new String(pack.getData(),0,pack.getLength());
			if(message.startsWith("end")) {
				break;
		}
		out.write(pack.getData(),0,pack.getLength());
	}
	byte imagebyte[]=out.toByteArray();
	out.close();
	Toolkit tool=getToolkit();			//getToolKit()就是返回ToolKit类的一个实例。
	Image image=tool.createImage(imagebyte);			//创建可变图像
	canvas.setImage(image);
	canvas.repaint();
	validate();
	}
	catch(IOException e){}
}
 public static void main(String args[]) {
	 new ClientGetImage();
 	}
}

package 传输图像;
import java.net.*;
import java.io.*;
public class ServerImage {
	public static void main(String args[]) {
		DatagramPacket pack=null;
		DatagramSocket mailReceive=null;
		ServerThread thread;
		byte b[]=new byte[8192];
		InetAddress address=null;
		pack=new DatagramPacket(b,b.length);
		while(true) {
			try{ mailReceive= new DatagramSocket(5678);
			}
			catch(IOException e1) {
				System.out.println("正在等待");
			}
			try{ mailReceive.receive(pack);
			address=pack.getAddress();
			System.out.println("客户的地址:"+address);
			}
			catch (IOException e) {}
			if(address!=null) {
				new ServerThread(address).start();
			}
		}
	}
}
class ServerThread extends Thread {
	InetAddress address;
	DataOutputStream out=null;
	DataInputStream in=null;
	String s=null;
	ServerThread(InetAddress address) {
		this.address=address;
 }
 public void run() {
	 FileInputStream in;
	 byte b[]=new byte[8192];
	 try{ in=new FileInputStream ("src/传输图像/images/1.jpg");
	 int n=-1;
	 while((n=in.read(b))!=-1) {
		 DatagramPacket data=new DatagramPacket(b,n,address,5678);
		 DatagramSocket mailSend=new DatagramSocket();
		 mailSend.send(data);
	 }
	 in.close();
	 byte end[]="end".getBytes();
	 DatagramPacket data=new DatagramPacket(end,end.length,address,5678);
	 DatagramSocket mailSend=new DatagramSocket();
	 mailSend.send(data);
	 }
	 catch(Exception e){}
 	}
}

link中的函数知道了它的地址可以复制么？如何调用成员函数而不经过实例化？

zjbonrace

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