pro2.java

total是最后的版本。包括的全是最新的物理层和数据链路层。另外还有pro1和pro2的打包程序和调用它们形成的各自的界面程序

/*Protocol 2 (stop-and-wait) also provides for a one-directional 
 *flow cheng of quan data from sender to receiver.The communication
 *channel is once again assumed to be error free, as in protocol 1.
 *However, this time, the receiver has only a finite buffer capacity
 *and a finite procesing speed, so the protocol must explicitly 
 *prevent the sender from flooding the receiver with data faster 
 *than it can be handled.*/

package chq;

import chq.frame;
import chq.DatalinkLayer;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Pro2// extends JFrame implements ActionListener
{
	public String event;  
	
	private JTextField enter;
    private JTextArea display;
    public frame fs,fr,ac;
    public DatalinkLayer datalink=new DatalinkLayer();
    
	public frame sending(String address,int port,String pfn)
	{
		//while(true){
			fs=new frame("data",0,0,pfn);
			
			fs.framing();
			String ftp=fs.getFormedFrame();
			
			datalink.to_PhysicalLayer(address,port,ftp);
			//} //end while
			return fs;
	}
	
	public frame receiving()
	{
		while(true)
		{
			event=datalink.waitfor_Event(event);  //ack arrival is only possibility
									
			String r=datalink.from_PhysicalLayer();
			fr=new frame();
			fr.unFraming(r);
			
			return fr;
		}	
	}
	
	public frame returnAck()
	{
		ac=new frame("ack",0,0,"");
		ac.framing();
		String acf=ac.getFormedFrame();
		
		datalink.to_PhysicalLayer(datalink.phy.getRPAddress(),
			datalink.phy.getRPPort(),acf);
		
		return ac;
	}
	
}