问题
I ve created a simple MultiThreaded server. Everytime it accepts client a DataInputStream and DataOutputStream is created and the comunication start
Server:
public class Connection implements Runnable{
boolean isAlreadyOpened = false;
@Override
public void run() {
// TODO Auto-generated method stub
try {
ServerSocket ss = new ServerSocket(7000);
while(true){
System.out.println("Il Server sta cercando Connessioni");
Socket s = ss.accept();
System.out.println("Il Server ha accettato un Client");
Thread t2 = new Thread(new Runnable(){
public void run(){
try {
DataInputStream dis = new DataInputStream(s.getInputStream());
isAlreadyOpened = true;
DataOutputStream dos = new DataOutputStream(s.getOutputStream());
while(true){
String test = dis.readUTF();
dos.writeUTF(test);
System.out.println(test);
dos.flush();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
isAlreadyOpened = false;
}
}
});
t2.start();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
I ve tried to connect an Android application and a JavaApp; every 40 seconds both of these programs send a string via writeUTF. The connection is established correctly from both Clients but the server receives Data just from the last one that connects to server. How can I allow the server to receive/send the data from/to ALL the clients?
EDIT:
I ve tried to set this:
public class Connection implements Runnable {
@Override
public void run() {
try {
ServerSocket ss = new ServerSocket(7000);
while (true) {
System.out.println("Server is listening");
Socket s = ss.accept();
System.out.println("Client Accepted");
Thread t2 = new Thread(new Runnable() {
public void run() {
try {
DataInputStream dis = new DataInputStream(s.getInputStream());
DataOutputStream dos = new DataOutputStream(s.getOutputStream());
while (true) {
String test = dis.readUTF();
dos.writeUTF(test);
System.out.println(test);
dos.flush();
}
} catch (IOException
e.printStackTrace();
} finally {
try {
s.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
});
t2.start();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
But the result is the same
EDIT:
Andorid Client Code
public class Connection implements Runnable {
@Override
public void run() {
try {
Socket s = new Socket("127.0.0.1", 7000);
DataInputStream dis = new DataInputStream(s.getInputStream());
DataOutputStream dos = new DataOutputStream(s.getOutputStream());
while(true){
dos.writeUTF("FromAndroid");
Log.d("InputStreammmm", dis.readUTF());
Thread.sleep(10000)
}
} catch (IOException e) {
e.printStackTrace();
}
}
JAVA APP CLIENT CODE
@Override
public void run() {
try {
Socket socket = new Socket("127.0.0.1", 7000);
System.out.println("Connessooo");
DataInputStream dis = new DataInputStream(socket.getInputStream());
DataOutputStream dos = new DataOutputStream(socket.getOutputStream());
while(true){
dos.writeUTF("Invioooooooooooooooooooooooooo");
result = dis.readUTF();
System.out.println(result);
Thread.sleep(10000);
}
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
EDIT WITH LIST OF SOCKET:
public class Connection implements Runnable {
List<Socket> sList = new ArrayList<>();
Socket s;
int i = 0;
@Override
public void run() {
// TODO Auto-generated method stub
try {
ServerSocket ss = new ServerSocket(7000);
while (true) {
System.out.println("Server Listening");
s = ss.accept();
sList.add(s);
System.out.println("Accepted Client --- " +s.toString());
Thread t2 = new Thread(new Runnable() {
public void run() {
try {
DataInputStream dis = new DataInputStream(s.getInputStream());
while (true)
{
String test = dis.readUTF();
System.out.println("Message sent from -- " + sList.get(i).toString());
System.out.println(test);
while(i < sList.size()){
DataOutputStream dos = new DataOutputStream(sList.get(i).getOutputStream());
dos.writeUTF(test);
System.out.println("Message Sent to -- " + sList.get(i).toString());
dos.flush();
++i;
}
i=0;
}
} catch (IOException e)
{
e.printStackTrace();
} finally
{
try
{
System.out.println("Closing Socket --- " + sList.get(i).toString());
sList.get(i).close();
sList.remove(i);
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
});
t2.start();
}
} catch (IOException e) {
e.printStackTrace();
}
}
Doing in this way my problem is solved as suggested by EJP...
回答1:
Cannot reproduce.
Test program, copy-pasted from your edited code and added final to Socket s as I am using Java 7, and added client code:
public class Connection implements Runnable
{
@Override
public void run()
{
try
{
ServerSocket ss = new ServerSocket(7000);
while (true)
{
System.out.println("Server is listening");
final Socket s = ss.accept();
System.out.println("Client Accepted");
Thread t2 = new Thread(new Runnable()
{
public void run()
{
try
{
DataInputStream dis = new DataInputStream(s.getInputStream());
DataOutputStream dos = new DataOutputStream(s.getOutputStream());
while (true)
{
String test = dis.readUTF();
dos.writeUTF(test);
System.out.println(test);
dos.flush();
}
}
catch (IOException e)
{
e.printStackTrace();
}
finally
{
try
{
s.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
});
t2.start();
}
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void main(String[] args) throws InterruptedException
{
Connection c = new Connection();
Thread t1 = new Thread(c);
t1.setDaemon(true);
t1.start();
Runnable r = new Runnable()
{
public void run()
{
try (Socket s = new Socket("localhost", 7000))
{
DataOutputStream dos = new DataOutputStream(s.getOutputStream());
DataInputStream dis = new DataInputStream(s.getInputStream());
for (int i = 0; i < 10; i++)
{
dos.writeUTF("Hello from "+Thread.currentThread().getName());
String reply = dis.readUTF();
Thread.sleep(10*1000);
}
}
catch (IOException|InterruptedException exc)
{
exc.printStackTrace();
}
}
};
Thread t2 = new Thread(r);
Thread t3 = new Thread(r);
t2.start();
t3.start();
t2.join();
t3.join();
}
}
Output:
Server is listening
Client Accepted
Server is listening
Client Accepted
Server is listening
Hello from Thread-1
Hello from Thread-2
Hello from Thread-2
Hello from Thread-1
Hello from Thread-2
Hello from Thread-1
Hello from Thread-2
Hello from Thread-1
Hello from Thread-1
Hello from Thread-2
Hello from Thread-1
Hello from Thread-2
Hello from Thread-2
Hello from Thread-1
Hello from Thread-1
Hello from Thread-2
Hello from Thread-2
Hello from Thread-1
Hello from Thread-2
Hello from Thread-1
来源：https://stackoverflow.com/questions/35350949/multithreaded-server-receives-data-from-just-one-client-java