Java 客户端服务器UDP连接
我试图将数据从服务器一次发送1位到客户端。每当客户端从服务器接收到一个比特时，它都应该用ACK进行响应 当前发生的情况是，当客户机向服务器发送初始请求时，数据被传递到服务器。当服务器向客户机发送所需的数据时，数据被循环回自身，客户机处于无限等待状态 我在下面附上了客户端和服务器的代码。请看一看，并就我的错误提出建议 客户端：Java 客户端服务器UDP连接,java,udp,client-server,Java,Udp,Client Server,我试图将数据从服务器一次发送1位到客户端。每当客户端从服务器接收到一个比特时，它都应该用ACK进行响应 当前发生的情况是，当客户机向服务器发送初始请求时，数据被传递到服务器。当服务器向客户机发送所需的数据时，数据被循环回自身，客户机处于无限等待状态 我在下面附上了客户端和服务器的代码。请看一看，并就我的错误提出建议 客户端： import java.io.IOException; import java.net.*; import java.util.Scanner; c
import java.io.IOException;
import java.net.*;
import java.util.Scanner;
class UDPClient extends Thread implements Runnable
{
DatagramSocket clientSocket;
InetAddress IPAddress;
public static void main(String args[]) throws Exception
{
try
{
UDPClient t1 = new UDPClient();
Thread t = new Thread(t1);
t.start();
}
catch (Exception e)
{
System.out.println("Error!");
}
}
public UDPClient() throws Exception
{
this.clientSocket = new DatagramSocket();
this.IPAddress = InetAddress.getByName("Localhost");
clientSocket.setSoTimeout(5000);
}
public void run()
{
byte[] sendData = new byte[1024];
byte[] receiveData = new byte[1024];
String m ="1001";
String checksum = "1111";
String checksumSend = "";
String sentence="";
String sentence1="";
String dataRequired="";
try
{
dataRequired = dataRequired.concat(m+":Data");
sendData = dataRequired.getBytes();
DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, 9876);
clientSocket.send(sendPacket);
checksumSend = checksumSend.concat(checksum+":checksum");
sendData = checksumSend.getBytes();
DatagramPacket sendPacket2 = new DatagramPacket(sendData, sendData.length, IPAddress, 9876);
clientSocket.send(sendPacket2);
Scanner in = new Scanner(System.in);
System.out.println("Enter the Window size: ");
int s = in.nextInt();
String WinSize="";
WinSize = WinSize.concat(s+":Windowsize");
sendData = WinSize.getBytes();
DatagramPacket sendPacket3 = new DatagramPacket(sendData, sendData.length, IPAddress, 9876);
clientSocket.send(sendPacket3);
String finished="Finished";
sendData = finished.getBytes();
DatagramPacket sendPacket6 = new DatagramPacket(sendData, sendData.length, IPAddress, 9876);
clientSocket.send(sendPacket6);
do
{
try
{
DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
System.out.println("I am getting executed");
clientSocket.receive(receivePacket); //After this step, nothing gets executed
sentence = new String(receivePacket.getData(),0,receivePacket.getLength());
System.out.println("Received from Server: " + sentence);
if(receivePacket != null)
sentence1 = "ACK";
sendData = sentence1.getBytes();
DatagramPacket sendPacket4 =
new DatagramPacket(sendData, sendData.length, IPAddress, 9876);
clientSocket.send(sendPacket4);
}
catch (SocketTimeoutException a)
{
System.out.println("Timed out!");
}
}while(sentence!=null);
}
catch (IOException e)
{
System.err.println(e);
}
finally
{
clientSocket.close();
}
}
}
import java.io.IOException;
import java.net.*;
public class UDPServer extends Thread implements Runnable
{
DatagramSocket serverSocket;
public static void main(String args[]) throws Exception
{
try
{
UDPServer t1 = new UDPServer();
Thread t = new Thread(t1);
t.start();
}
catch (Exception e)
{
System.out.println("Error!");
}
}
public UDPServer() throws Exception
{
this.serverSocket = new DatagramSocket(9876);
}
public void run()
{
byte[] receiveData = new byte[1024];
byte[] sendData = new byte[1024];
String checksum="";
String Data = "";
String WinSize = "";
String carry = "0";
String output="";
String n,o;
String output1;
String sentence1="";
int i,j=0;
while(true)
{
String sentence="";
try
{
DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
serverSocket.receive(receivePacket);
InetAddress IPAddress = receivePacket.getAddress();
sentence = new String( receivePacket.getData(),0,receivePacket.getLength());
if(sentence.contains("checksum"))
{
int len = sentence.length();
for(i=0;i<len;i++)
{
if(sentence.charAt(i)==':')
{
checksum = sentence.substring(0,i);
}
}
System.out.println("Checksum as specified by client is: " + checksum);
}
else if(sentence.contains("Data"))
{
int len = sentence.length();
for(i=0;i<len;i++)
{
if(sentence.charAt(i)==':')
{
Data = sentence.substring(0,i);
}
}
System.out.println("Data requested by client is: " + Data);
}
else if(sentence.contains("Windowsize"))
{
int len = sentence.length();
for(i=0;i<len;i++)
{
if(sentence.charAt(i)==':')
{
WinSize = sentence.substring(0,i);
}
}
System.out.println("Window Size is: " + WinSize);
}
else if(sentence.contains("Finished"))
{
output1 = checksumAdd(carry,Data,checksum);
output = reverse(output1);
System.out.println("Checksum Addition before complementing digits = "+output);
output = complement(output);
output = reverse(output);
System.out.println("Checksum Addition after complementing digits = "+output);
int WindowSize = Integer.parseInt(WinSize);
int strlen = Data.length();
do
{
for(i=j;i<(WindowSize+j);i++)
{
if(i!=strlen)
{
String send = "";
n = Data.substring(i,i+1);
System.out.println("Value of n is: "+n);
send = send.concat(n+":");
o = output.substring(i,i+1);
System.out.println("Value of o is: "+o);
send = send.concat(o);
sendData = send.getBytes();
DatagramPacket sendPacket1 = new DatagramPacket(sendData, sendData.length, IPAddress, 9876);
serverSocket.send(sendPacket1);
}
else
break;
}
j+=WindowSize;
DatagramPacket receivePacket2 = new DatagramPacket(receiveData, receiveData.length);
serverSocket.receive(receivePacket2);
sentence1 = new String( receivePacket2.getData(),0,receivePacket2.getLength());
System.out.println("sentence 1 is: "+sentence1); //To be removed. Used for testing purposes
}while(i!=strlen);
}
}
catch (IOException e)
{
System.err.println(e);
}
}
}
public static String complement(String output) {
String temp="";
int len = output.length();
for(int i=len;i>0;i--)
{
String t = output.substring(i-1,i);
if(t.equals("0"))
temp = temp.concat("1");
else if(t.equals("1"))
temp = temp.concat("0");
}
return temp;
}
public static String reverse(String output)
{
String temp="";
int len = output.length();
for(int i=len;i>0;i--)
{
String t = output.substring(i-1,i);
temp = temp.concat(t);
}
return temp;
}
public static String checksumAdd(String carry, String Data,String checksum)
{
int strlen = Data.length();
int flag=0;
String output="";
String output2="";
String n,che;
String sum = null;
for(int i=strlen;i>0;i--)
{
n=Data.substring(i-1,i);
che = checksum.substring(i-1,i);
if(n.equals("0") && che.equals("0") && carry.equals("0"))
{
sum = "0";
carry = "0";
}
else if(n.equals("0") && che.equals("0") && carry.equals("1"))
{
sum = "1";
carry = "0";
}
else if(n.equals("0") && che.equals("1") && carry.equals("0"))
{
sum = "1";
carry = "0";
}
else if(n.equals("0") && che.equals("1") && carry.equals("1"))
{
sum = "0";
carry = "1";
}
else if(n.equals("1") && che.equals("0") && carry.equals("0"))
{
sum = "1";
carry = "0";
}
else if(n.equals("1") && che.equals("0") && carry.equals("1"))
{
sum = "0";
carry = "1";
}
else if(n.equals("1") && che.equals("1") && carry.equals("0"))
{
sum = "0";
carry = "1";
}
else if(n.equals("1") && che.equals("1") && carry.equals("1"))
{
sum = "1";
carry = "1";
}
output = output.concat(sum);
}
if(carry.equals("1"))
{
n = output.substring(0,1);
if(n.equals("0"))
{
sum = "1";
carry = "0";
}
else if(n.equals("1"))
{
sum = "0";
carry = "1";
}
output2 = output2.concat(sum);
for(int i=strlen-1;i>0;i--)
{
n=Data.substring(i-1,i);
if(n.equals("0") && carry.equals("0"))
{
sum = "0";
carry = "0";
}
else if(n.equals("0") && carry.equals("1"))
{
sum = "1";
carry = "0";
}
else if(n.equals("1") && carry.equals("0"))
{
sum = "1";
carry = "0";
}
else if(n.equals("1") && carry.equals("1"))
{
sum = "0";
carry = "1";
}
output2 = output2.concat(sum);
}
flag = 1;
}
if (flag==1)
return output2;
return output;
}
}
import java.io.IOException；
导入java.net。*；
公共类UDPServer扩展线程实现可运行
{
DatagramSocket服务器套接字；
公共静态void main（字符串args[]）引发异常
{
尝试
{
UDPServer t1=新的UDPServer（）；
螺纹t=新螺纹（t1）；
t、 start（）；
}
捕获（例外e）
{
System.out.println（“错误！”）；
}
}
公共UDPServer（）引发异常
{
this.serverSocket=newdatagramsocket（9876）；
}
公开募捐
{
字节[]接收数据=新字节[1024]；
字节[]发送数据=新字节[1024]；
字符串校验和=”；
字符串数据=”；
字符串WinSize=“”；
字符串进位=“0”；
字符串输出=”；
字符串n，o；
字符串输出1；
字符串语句1=“”；
int i，j=0；
while（true）
{
字符串句子=”；
尝试
{
DatagramPacket receivePacket=新的DatagramPacket（receiveData，receiveData.length）；
serverSocket.receive（接收数据包）；
InetAddress IPAddress=receivePacket.getAddress（）；
句子=新字符串（receivePacket.getData（），0，receivePacket.getLength（））；
if（句子包含（“校验和”））
{
int len=句子长度（）；
对于（i=0；i0；i--）
{
n=数据子串（i-1，i）；
如果（n等于（“0”）&进位等于（“0”））
{
sum=“0”；
进位=“0”；
}
如果（n等于（“0”）&进位等于（“1”））
{
sum=“1”；
进位=“0”；
}
如果（n等于（“1”）&进位等于（“0”））
{
sum=“1”；
进位=“0”；
}
否则，如果（n等于（“1”）&进位等于（“1”））
{
sum=“0”；
进位=“1”；
}
output2=output2.concat（总和）；
}
flag=1；
}
如果（标志==1）
返回输出2；
返回输出；
}
}
serverSocket.send(sendPacket1);
您是否尝试在if块内的控制台中输出一些文本，以查看是否/何时进入该循环？是的。我已经使用以下5个命令完成了此操作：System.out.println（“n的值为：”+n）；send=send.concat（n+“：”）；o=output.substring（I，I+1）；System.out.println（“o的值为：”+o）；PS-如何在回复中分隔行？我使用Shift+Enter，但行都集中在一起而不是分开。不可能通过UDP发送一位，而您没有这样做。“UDP连接”在术语上已经是一个矛盾。不清楚您在问什么。