Java 无法在客户端和服务器之间建立UDP连接
基本上，我正在编写一个简单的TCP-UDP多客户端GUI程序。我可以建立到服务器的Java 无法在客户端和服务器之间建立UDP连接,java,sockets,tcp,udp,datagram,Java,Sockets,Tcp,Udp,Datagram,基本上，我正在编写一个简单的TCP-UDP多客户端GUI程序。我可以建立到服务器的TCP连接，但不能建立UDP连接。服务器正在侦听端口4000。我在GUI客户端上有一个组合框，其中包含元素TCP和UDP。如果用户选择UDP并单击Connect.它将通过调用UDPconnection方法尝试建立UDP连接 以下是我的客户端GUI代码： public void UDPconnection() { try { done = false; datagram
TCPUDP4000。组合框，其中包含元素TCP
和UDP。
如果用户选择UDP
并单击Connect.
它将通过调用UDPconnection
方法尝试建立UDP
连接
以下是我的客户端GUI代码：
public void UDPconnection()
{
try
{
done = false;
datagramSocket = new DatagramSocket(serverPort);
}
catch (SocketException e)
{
done = true;
System.out.println("Host not available");
}
}
public class chatServer2 implements Runnable {
private int clientCount = 0;
private ChatServerThread clients[] = new ChatServerThread[50];
private ServerSocket server = null;
Thread thread = null;
//same as version3
public chatServer2(int port){
try{
server = new ServerSocket(port);//step1
System.out.println("Started the server...waiting for a client");
start(); //the chatserver's start method that goes ahead and creates a new thread
}
catch(IOException e){
System.err.println("ERROR "+e.getMessage());
}
}
public void start(){
if(thread == null){
thread = new Thread(this);
thread.start();
}
}
@Override
public void run() {//same as version 3
while(thread !=null){
try{
System.out.println("Waiting for a client...");
//now we add a new Thread and accept a client
addThread(server.accept());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void addThread(Socket socket){
if(clientCount < clients.length){
clients[clientCount] = new ChatServerThread(this, socket);
try {
clients[clientCount].open();//open the stream for the ChatServerThread client
clients[clientCount].start();//start to run the ChatServerThread client
clientCount++;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public synchronized void handle(int ID, String input)
{
System.out.println(input);
if(input.equalsIgnoreCase("bye"))
{
remove(ID);//person said bye so remove them
}
else
{
System.out.println(input);
for (int i = 0; i < clientCount; i++)
{
clients[i].send("User: " + ID + ": " + input);
}
}
}
public synchronized void remove(int ID){
int position = findClient(ID);
if(position >=0){
ChatServerThread toRemove = clients[position];
if(position <clientCount-1){
for(int i= position+1; i <clientCount; i++){
clients[i-1] = clients[i];
}
clientCount--;
}
try {
toRemove.close();//close the person's that said bye connection
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
private int findClient(int ID){
for(int i=0; i<clientCount; i++){
if(clients[i].getID() == ID){
return i;
}
}
return -1;//not in the array
}
public static void main(String [] args){
chatServer2 l = new chatServer2(4000);
}
}
这是我的聊天服务器代码：
public void UDPconnection()
{
try
{
done = false;
datagramSocket = new DatagramSocket(serverPort);
}
catch (SocketException e)
{
done = true;
System.out.println("Host not available");
}
}
public class chatServer2 implements Runnable {
private int clientCount = 0;
private ChatServerThread clients[] = new ChatServerThread[50];
private ServerSocket server = null;
Thread thread = null;
//same as version3
public chatServer2(int port){
try{
server = new ServerSocket(port);//step1
System.out.println("Started the server...waiting for a client");
start(); //the chatserver's start method that goes ahead and creates a new thread
}
catch(IOException e){
System.err.println("ERROR "+e.getMessage());
}
}
public void start(){
if(thread == null){
thread = new Thread(this);
thread.start();
}
}
@Override
public void run() {//same as version 3
while(thread !=null){
try{
System.out.println("Waiting for a client...");
//now we add a new Thread and accept a client
addThread(server.accept());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void addThread(Socket socket){
if(clientCount < clients.length){
clients[clientCount] = new ChatServerThread(this, socket);
try {
clients[clientCount].open();//open the stream for the ChatServerThread client
clients[clientCount].start();//start to run the ChatServerThread client
clientCount++;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public synchronized void handle(int ID, String input)
{
System.out.println(input);
if(input.equalsIgnoreCase("bye"))
{
remove(ID);//person said bye so remove them
}
else
{
System.out.println(input);
for (int i = 0; i < clientCount; i++)
{
clients[i].send("User: " + ID + ": " + input);
}
}
}
public synchronized void remove(int ID){
int position = findClient(ID);
if(position >=0){
ChatServerThread toRemove = clients[position];
if(position <clientCount-1){
for(int i= position+1; i <clientCount; i++){
clients[i-1] = clients[i];
}
clientCount--;
}
try {
toRemove.close();//close the person's that said bye connection
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
private int findClient(int ID){
for(int i=0; i<clientCount; i++){
if(clients[i].getID() == ID){
return i;
}
}
return -1;//not in the array
}
public static void main(String [] args){
chatServer2 l = new chatServer2(4000);
}
}
公共类chatServer2实现可运行{
private int clientCount=0；
私有ChatServerThread客户端[]=新ChatServerThread[50]；
私有服务器套接字服务器=null；
线程=空；
//与版本3相同
公共聊天服务器2（int端口）{
试一试{
服务器=新服务器套接字（端口）；//步骤1
System.out.println（“启动服务器…等待客户端”）；
start（）；//继续并创建新线程的chatserver的start方法
}
捕获（IOE异常）{
System.err.println（“ERROR”+e.getMessage（））；
}
}
公开作废开始（）{
如果（线程==null）{
线程=新线程（此）；
thread.start（）；
}
}
@凌驾
public void run（）{//与版本3相同
while（线程！=null）{
试一试{
System.out.println（“等待客户…”）；
//现在我们添加一个新线程并接受一个客户端
addThread（server.accept（））；
}捕获（IOE异常）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
}
}
}
公共void addThread（套接字）{
if（clientCount=0）{
ChatServerThread toRemove=客户端[位置]；
如果（位置）
首先，没有所谓的“UDP连接”
在指定端口上创建DatagramSocket
失败并不意味着“主机不可用”。请查看异常消息以了解其含义
UDP不与TCP进行互操作，特别是与JavaServerSockets
不进行互操作。两端需要一个DatagramSocket
或DatagramChannel
，并且没有连接阶段：只需来回发送数据报