我正在尝试使用此源代码以了解网络编程。它最初是通过这三个类发送数据包，但即使使用相同的代码也不会再发送数据包了。在输入no并且数据包未发送到第二个客户端后，在Tokenclient1类中发生此问题。
任何想法为什么不再有效？
import java.net.*;
public class TokenServer {
public static void main(String agrs[])throws Exception {
while(true) {
Server sr=new Server();
sr.recPort(8000);
sr.recData();
}
}
}
class Server {
boolean hasToken=false;
boolean sendData=false;
int recport;
void recPort(int recport) {
this.recport=recport;
}
void recData()throws Exception {
byte buff[]=new byte[256];
DatagramSocket ds;
DatagramPacket dp;
String str;
ds=new DatagramSocket(recport);
dp=new DatagramPacket(buff,buff.length);
ds.receive(dp);
ds.close();
str=new String(dp.getData(),0,dp.getLength());
System.out.println("The message is "+str);
}
}
import java.io.*;
import java.net.*;
public class TokenClient1 {
public static void main(String arg[]) throws Exception {
InetAddress lclhost;
BufferedReader br;
String str="";
TokenClient12 tkcl,tkser;
//boolean hasToken;
//boolean setSendData;
while(true) {
lclhost=InetAddress.getLocalHost();
tkcl = new TokenClient12(lclhost);
tkser = new TokenClient12(lclhost);
//tkcl.setSendPort(9001);
tkcl.setSendPort(9004);
tkcl.setRecPort(8002);
lclhost=InetAddress.getLocalHost();
tkser.setSendPort(9000);
if(tkcl.hasToken == true) {
System.out.println("Do you want to enter the Data --> YES/NO");
br=new BufferedReader(new InputStreamReader(System.in));
str=br.readLine();
if(str.equalsIgnoreCase("yes")) {
System.out.println("ready to send");
tkser.setSendData = true;
tkser.sendData();
tkser.setSendData = false;
}
else if(str.equalsIgnoreCase("no")) {
System.out.println("i m in else");
//tkcl.hasToken=false;
tkcl.sendData();
tkcl.recData();
System.out.println("i m leaving else");
}
}
else {
System.out.println("ENTERING RECEIVING MODE...");
tkcl.recData();
}
}
}
}
class TokenClient12 {
InetAddress lclhost;
int sendport,recport;
boolean hasToken = true;
boolean setSendData = false;
TokenClient12 tkcl,tkser;
TokenClient12(InetAddress lclhost) {
this.lclhost = lclhost;
}
void setSendPort(int sendport) {
this.sendport = sendport;
} void setRecPort(int recport) {
this.recport = recport;
}
void sendData() throws Exception {
BufferedReader br;
String str="Token";
DatagramSocket ds;
DatagramPacket dp;
if(setSendData == true) {
System.out.println("sending ");
System.out.println("Enter the Data");
br=new BufferedReader(new InputStreamReader(System.in));
str = "ClientOne....." + br.readLine();
System.out.println("now sending");
}
ds = new DatagramSocket(sendport);
dp = new DatagramPacket(str.getBytes(),str.length(),lclhost,sendport-1000);
ds.send(dp);
ds.close();
setSendData = false;
hasToken = false;
}
void recData()throws Exception {
String msgstr;
byte buffer[] = new byte[256];
DatagramSocket ds;
DatagramPacket dp;
ds = new DatagramSocket(recport);
dp = new DatagramPacket(buffer,buffer.length);
ds.receive(dp);
ds.close();
msgstr = new String(dp.getData(),0,dp.getLength());
System.out.println("The data is "+msgstr);
if(msgstr.equals("Token")) {
hasToken = true;
}
}
}
import java.io.*;
import java.net.*;
public class TokenClient2 {
static boolean setSendData ;
static boolean hasToken ;
public static void main(String arg[]) throws Exception {
InetAddress lclhost;
BufferedReader br;
String str1;
TokenClient21 tkcl;
TokenClient21 ser;
while(true) {
lclhost=InetAddress.getLocalHost();
tkcl = new TokenClient21(lclhost);
tkcl.setRecPort(8004);
tkcl.setSendPort(9002);
lclhost=InetAddress.getLocalHost();
ser = new TokenClient21(lclhost);
ser.setSendPort(9000);
System.out.println("entering if");
if(hasToken == true) {
System.out.println("Do you want to enter the Data --> YES/NO");
br=new BufferedReader(new InputStreamReader(System.in));
str1=br.readLine();
if(str1.equalsIgnoreCase("yes")) {
System.out.println("ignorecase");
ser.setSendData = true;
ser.sendData(); }
else if(str1.equalsIgnoreCase("no")) {
tkcl.sendData();
hasToken=false;
}
}
else {
System.out.println("entering recieving mode");
tkcl.recData();
hasToken=true;
}
}
}
}
class TokenClient21 {
InetAddress lclhost;
int sendport,recport;
boolean setSendData = false;
boolean hasToken = false;
TokenClient21 tkcl;
TokenClient21 ser;
TokenClient21(InetAddress lclhost) {
this.lclhost = lclhost; }
void setSendPort(int sendport) {
this.sendport = sendport;
}
void setRecPort(int recport) {
this.recport = recport;
}
void sendData() throws Exception {
System.out.println("case");
BufferedReader br;
String str="Token";
DatagramSocket ds;
DatagramPacket dp;
if(setSendData == true) {
System.out.println("Enter the Data");
br=new BufferedReader(new InputStreamReader(System.in));
str = "ClientTwo....." + br.readLine(); }
ds = new DatagramSocket(sendport);
dp = new DatagramPacket(str.getBytes(),str.length(),lclhost,sendport-1000);
ds.send(dp);
ds.close();
System.out.println("Data Sent");
setSendData = false;
hasToken = false;
}
void recData()throws Exception {
String msgstr;
byte buffer[] = new byte[256];
DatagramSocket ds;
DatagramPacket dp;
ds = new DatagramSocket(recport);
//ds = new DatagramSocket(4000);
dp = new DatagramPacket(buffer,buffer.length);
ds.receive(dp);
ds.close();
msgstr = new String(dp.getData(),0,dp.getLength());
System.out.println("The data is "+msgstr);
if(msgstr.equals("Token")) {
hasToken = true;
}
}
}
答案 0 :(得分：0)
您的程序按预期工作。请确保您并行运行所有三个程序，这意味着打开3个不同的命令提示并分别运行以下命令。
java TokenServer
java TokenClient1
java TokenClient2