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我正試圖在java中使用UDP網絡來設計一個聊天應用程序。UDP中的一個服務器和多客戶端聊天框
這裏是我的服務器：
package ChatBox;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.util.Hashtable;
import java.util.StringTokenizer;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Server implements Runnable {
public Hashtable<String, InetAddress> table;
public Hashtable<String, Integer> tab;
DatagramSocket sock = new DatagramSocket(5050);
DatagramPacket pack;
private String str[];
int Port;
Server(String str[]) throws SocketException, UnsupportedEncodingException, IOException {
this.str = str;
String Sname = str[2];
System.out.println(Sname);
byte[] data = new byte[1000];
pack = new DatagramPacket(data, data.length);
sock.receive(pack);
String s = new String(data, "UTF-8");
String s1 = s.replaceAll("\n", " ");
StringTokenizer st = new StringTokenizer(s1, " ");
int f1 = 0, f2 = 0, f3 = 0;
String sender;
while (st.hasMoreTokens()) {
String s2 = st.nextToken();
if (s2.equals("Via:")) {
if (st.nextToken().equals(Sname)) {
f1 = 1;
}
} else if (s2.equals("To:")) {
if (st.nextToken().equals(Sname)) {
f2 = 1;
}
}
else if(s2.equals("From:"))
{
sender = st.nextToken();
table.put(sender, pack.getAddress());
}
else if (s2.equals("Port:")) {
Port = Integer.parseInt(st.nextToken());
if (tab.get(Port) != null) {
f3 = 1;
}
}
}
if ((f1 == 1) && (f2 == 1) && (f3 == 1)) {
new Thread(this).start();
} else {
if (f1 == 0) {
System.out.println("Warning: Server name mismatch. Message dropped.");
}
if (f2 == 0) {
System.out.println("Warning: Server name mismatch. Message dropped.");
}
if (f3 == 0) {
System.out.println("Warning: Unknown recipient. Message dropped.");
}
}
}
public void run() {
while (true) {
try {
String s;
String namefind;
String name = null;
byte[] data = new byte[1000];
DatagramPacket receivePack = new DatagramPacket(data, data.length);
sock.receive(receivePack);
System.out.println(new String(receivePack.getData()));
s = new String(data, "UTF-8");
String s1 = s.replaceAll("\n", " ");
StringTokenizer st = new StringTokenizer(s1, " ");
while (st.hasMoreTokens()) {
namefind=st.nextToken();
if (namefind.equals("Body:")) {
namefind = st.nextToken();
StringTokenizer namefind2 = new StringTokenizer(namefind, "$");
name = namefind2.nextToken();
tab.put(name, Port);
}
}
sendPackToClient(receivePack,name);
} catch (Exception e) {
System.out.println(e);
}
}
}
public void sendPackToClient(DatagramPacket receivePack,String name) throws IOException {
byte[] data = receivePack.getData();
String s = new String(data, "UTF-8");
InetAddress add = table.get(name);
DatagramPacket dp = new DatagramPacket(s.getBytes("UTF-8"), s.getBytes("UTF-8").length, add, Port);
sock.send(dp);
}
public static void main(String[] args) throws SocketException, IOException {
try {
String str[]={"java", "Server ","NetworkingAssignmentServer"};
new Server(str);
} catch (UnsupportedEncodingException ex) {
Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
這裏是我的客戶：
package ChatBox;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Client {
Thread send;
Thread accept;
DatagramPacket pack;
DatagramSocket sock;
private String str[];
String name, sname;
int listeningPort;
InetAddress server_ip;
String message, sender;
public Client(String s[]) throws UnsupportedEncodingException, IOException {
this.str = s;
name = str[2];
System.out.println(name);
listeningPort = Integer.parseInt(str[3]);
server_ip = InetAddress.getByName("127.0.0.1");
sname = str[5];
System.out.println(sname);
sock = new DatagramSocket(5050);
byte[] data = new byte[1000];
pack = new DatagramPacket(data, data.length);
sock.receive(pack);
String incoming = new String(data, "UTF-8");
String s1 = incoming.replaceAll("\n", " ");
StringTokenizer st = new StringTokenizer(s1, " ");
int f1 = 0, f2 = 0;
while (st.hasMoreTokens()) {
String s2 = st.nextToken();
if (s2.equals("Via:")) {
if (st.nextToken().equals(sname)) {
f1 = 1;
}
} else if (s2.equals("To:")) {
if (st.nextToken().equals(name)) {
f2 = 1;
}
}
}
if ((f1 == 1) && (f2 == 1)) {
send = new Thread() {
public void run() {
while (true) {
try {
InetAddress host = InetAddress.getByName("localhost");
try {
Scanner input = new Scanner(System.in);
String in = input.nextLine();
System.out.println(in);
StringBuffer str = new StringBuffer("");
str.append("Via: ");
str.append(sname + "\n");
str.append("To: " + sname + "\n");
str.append("From: " + name + "\n");
str.append("Body: " + in);
byte[] data = new byte[1000];
data = str.toString().getBytes("UTF-8");
DatagramPacket sendPack = new DatagramPacket(data, data.length, host, 5050);
sock.send(sendPack);
} catch (Exception e) {
System.out.println(e);
}
} catch (UnknownHostException ex) {
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
};
send.start();
accept = new Thread() {
public void run() {
while (true) {
try {
sock = new DatagramSocket(5050);
byte[] data = new byte[1000];
pack = new DatagramPacket(data, data.length);
sock.receive(pack);
String incoming = new String(data, "UTF-8");
String s1 = incoming.replaceAll("\n", " ");
StringTokenizer st = new StringTokenizer(s1, " ");
while (st.hasMoreTokens()) {
String s2 = st.nextToken();
if (s2.equals("From:")) {
s2 = st.nextToken();
StringTokenizer namefind = new StringTokenizer(s2, "$");
sender = namefind.nextToken();
} else if (s2.equals("Body:")) {
s2 = st.nextToken();
while (st.hasMoreTokens()) {
message = st.nextToken();
}
}
}
System.out.println(sender + " says: " + message);
} catch (UnknownHostException ex) {
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
} catch (SocketException ex) {
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
};
accept.start();
}
}
public static void main(String[] args) throws IOException {
String str[] = {"Java", "Client", "Sheba", "12345", " 127.0.0.1", "NetworkingAssignmentServer"};
new Client(str);
}
}
但我總是收到錯誤，如：
Exception in thread "main" java.net.BindException: Address already in use: Cannot bind
at java.net.DualStackPlainDatagramSocketImpl.socketBind(Native Method)
at java.net.DualStackPlainDatagramSocketImpl.bind0(DualStackPlainDatagramSocketImpl.java:84)
at java.net.AbstractPlainDatagramSocketImpl.bind(AbstractPlainDatagramSocketImpl.java:93)
at java.net.DatagramSocket.bind(DatagramSocket.java:392)
at java.net.DatagramSocket.<init>(DatagramSocket.java:242)
at java.net.DatagramSocket.<init>(DatagramSocket.java:299)
at java.net.DatagramSocket.<init>(DatagramSocket.java:271)
at ChatBox.Client.<init>(Client.java:44)
at ChatBox.Client.main(Client.java:140)
C:\Users\HP\AppData\Local\NetBeans\Cache\8.1\executor-snippets\run.xml:53: Java returned: 1
BUILD FAILED (total time: 0 seconds)
我應該做的？任何幫助將非常感激。
你至少應該嘗試在引發異常的代碼部分隔離開來。這是一個[最小示例]（http://stackoverflow.com/help/mcve）？ –
我認爲你的服務器和客戶端使用相同的端口和地址，你是否在同一臺PC上使用服務器和客戶端？ – user2760751
@ user2760751是的。可以。請告訴我應該在哪裏做出改變？ – IAmBlake