滑动窗口协议实现疑问
用java实现滑动窗口协议，就是先读一个文件，把他传到一个数据结构里，然后读出来，然后发送acknowledgement，然后在发送一段，比如0 ， 7 ，5，6，8，9，1 定义窗口大小如果是3的话，传到第三次就是一个循环，我现在的问题是只能传一次，不知道怎么收到acknowledgement了，用的是java io包的fileinputstream我的代码如下，请高手指点一下改怎么改进一下，想了好久了还是不行，谢谢！import java.util.*;
import *;
class Frames{
String type;
int sequenceNo;
int datasize;
byte data[];
public Frames(String t,int s,byte[] d){
type = t;
sequenceNo = s;
data = d;
}
public String gettype(){
return type;
}
public int getsequenceNo(){
return sequenceNo;
}
public int getdatasize(){
return datasize;
}
public byte[] getdata(){
return data;
}
}
class Send implements Runnable{
Frames inframe;
Frames ackframe;
String s;
Buffer<Frames> buffer;
Vector<Frames> iframe ;
Vector<Frames> aframe ;
int nextStart=0;
int windowStart=0;
int windowEnd;
int sequenceN;
byte a[] = new byte[10];
File f=new File("D:\\s\\test.txt");
FileInputStream in =null;
public Send(Buffer<Frames> b,Vector<Frames> iframe,Vector<Frames> aframe){
buffer = b;
this.iframe = iframe;
this.aframe = aframe;
}
public void run(){
try{
in = new FileInputStream(f);
}catch(FileNotFoundException e1){
System.out.println("can not find file");
System.exit(-1);
}
try{
in.read(a);
}catch(IOException e2){
System.out.println("fail");
System.exit(-1);
}
int windowEnd=(windowStart+(buffer.windowsize)-1)%(buffer.windowsize);
while(nextStart>=windowStart&&nextStart<windowEnd){
sequenceN = nextStart;
inframe = new Frames("Information",sequenceN,a);
System.out.println("Creat "+sequenceN+""+inframe.gettype()+" frame");
nextStart=nextStart+1;
buffer.put(inframe);
System.out.println("Send NO."+sequenceN+" frame");
}
try{
in.close();
}catch(IOException e3){}
try{
Thread.sleep(2000);
}catch(InterruptedException ea){}
}
}
class Receive implements Runnable{
byte c[];
Frames inframe;
Frames ackframe;
String s;
Buffer<Frames> buffer;
Vector<Frames> iframe;
Vector<Frames> aframe;
int windowStart=0;
int windowEnd;
int nextStart=0;
int ackN;
File f = new File("D:\\s\\new.txt");
FileOutputStream out = null;
public Receive(Buffer<Frames> b,Vector<Frames> iframe,Vector<Frames> aframe){
buffer = b;
this.iframe = iframe;
this.aframe = aframe;
}
public void run(){
try{
out = new FileOutputStream(f);
}catch(FileNotFoundException e){
System.out.println("fail");
System.exit(-1);
}
int windowEnd=(windowStart+(buffer.windowsize)-1)%(buffer.windowsize);
while(nextStart>=windowStart&&nextStart<windowEnd){
ackN=nextStart;
ackframe = buffer.get();
System.out.println("Recevie NO."+ackN+" frame");
nextStart=nextStart+1;
c = buffer.get().getdata();
try{
out.write(c);
}catch(IOException e2){}
}
try{
out.close();
}catch(IOException ea){}
}
}
class Buffer<Frames>{
Vector<Frames> iframe;
Vector<Frames> aframe;
public int windowsize;
private int size = 0;
public Buffer(Vector<Frames> iframe, Vector<Frames> aframe,int w){
this.iframe=iframe;
this.aframe=aframe;
windowsize = w;
}
synchronized void put(Frames f){
while(size == windowsize){
try{
wait();
}
catch(InterruptedException e){}
}
iframe.add(f);
size++;
if(size == 0)notify();
}
synchronized Frames get(){
while(size == 0){
try{
wait();
}
catch(InterruptedException e){}
}
Frames temp = iframe.get(0);
iframe.remove(0);
size--;
if(size==windowsize)notify();
return temp;
}
}
public class Assignment{
public static void main(String args[]){
Scanner input = new Scanner(System.in);
System.out.println("Please enter the size of window");
int t =input.nextInt();
Vector<Frames> i = new Vector<Frames>();
Vector<Frames> a = new Vector<Frames>();
Buffer b=new Buffer(i,a,t);
new Thread(new Send(b,i,a)).start();
new Thread(new Receive(b,i,a)).start();
}
}
BSc_4_-_ADN_-_Assignment_2_-_sliding_window_protocol_2007.pdf
