Hi,
ich habe hier einen Chatserver und einen Client aus dem Java HeadFirst Buch. Es funktioniert alles.
In der Methode IncomingReader verstehe ich nicht wieso die while-Schleife in Zeile 93 keinen Endlostext in der Konsole oder GUI ausgibt. message wird doch niemals null. Ich meine es müsste unendlich "read " auf der Konsole ausgegeben werden. Was verstehe ich da falsch?
Hier der Quelltext für den Client und den Server:
[/code]
ich habe hier einen Chatserver und einen Client aus dem Java HeadFirst Buch. Es funktioniert alles.
In der Methode IncomingReader verstehe ich nicht wieso die while-Schleife in Zeile 93 keinen Endlostext in der Konsole oder GUI ausgibt. message wird doch niemals null. Ich meine es müsste unendlich "read " auf der Konsole ausgegeben werden. Was verstehe ich da falsch?
Hier der Quelltext für den Client und den Server:
Code:
import java.io.*;
import java.net.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class SimpleChatClient {
JTextArea incoming;
JTextField outgoing;
BufferedReader reader;
PrintWriter writer;
Socket sock;
public static void main(String[] args) {
SimpleChatClient client = new SimpleChatClient();
client.go();
}
public void go() {
// build gui
JFrame frame = new JFrame("Simple Chat Client");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel mainPanel = new JPanel();
incoming = new JTextArea(15,20); // was 15,50
incoming.setLineWrap(true);
incoming.setWrapStyleWord(true);
incoming.setEditable(false);
JScrollPane qScroller = new JScrollPane(incoming);
qScroller.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
qScroller.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
outgoing = new JTextField(20);
JButton sendButton = new JButton("Send");
sendButton.addActionListener(new SendButtonListener());
mainPanel.add(qScroller);
mainPanel.add(outgoing);
mainPanel.add(sendButton);
setUpNetworking();
Thread readerThread = new Thread(new IncomingReader());
readerThread.start();
frame.getContentPane().add(BorderLayout.CENTER, mainPanel);
frame.setSize(400,500);
frame.setVisible(true);
} // close go
private void setUpNetworking() {
try {
sock = new Socket("localhost", 5000);
InputStreamReader streamReader = new InputStreamReader(sock.getInputStream());
reader = new BufferedReader(streamReader);
writer = new PrintWriter(sock.getOutputStream());
System.out.println("networking established");
} catch(IOException ex) {
ex.printStackTrace();
}
} // close setUpNetworking
public class SendButtonListener implements ActionListener {
public void actionPerformed(ActionEvent ev) {
try {
writer.println(outgoing.getText());
writer.flush();
} catch(Exception ex) {
ex.printStackTrace();
}
outgoing.setText("");
outgoing.requestFocus();
}
} // close SendButtonListener inner class
public class IncomingReader implements Runnable {
public void run() {
String message;
try {
while ((message = reader.readLine()) != null) {
System.out.println("read " + message);
incoming.append(message + "\n");
} // close while
} catch(Exception ex) {ex.printStackTrace();}
} // close run
} // close inner class
Code:
import java.io.*;
import java.net.*;
import java.util.*;
public class VerySimpleChatServer {
ArrayList<PrintWriter> clientOutputStreams;
public class ClientHandler implements Runnable {
BufferedReader reader;
Socket sock;
public ClientHandler(Socket clientSocket) {
try {
sock = clientSocket;
InputStreamReader isReader = new InputStreamReader(sock.getInputStream());
reader = new BufferedReader(isReader);
} catch(Exception ex) {ex.printStackTrace();}
} // close constructor
public void run() {
String message;
try {
while ((message = reader.readLine()) != null) {
System.out.println("read " + message);
tellEveryone(message);
} // close while
} catch(Exception ex) {ex.printStackTrace();}
} // close run
} // close inner class
public static void main (String[] args) {
new VerySimpleChatServer().go();
}
public void go() {
clientOutputStreams = new ArrayList<PrintWriter>();
try {
ServerSocket serverSock = new ServerSocket(5000);
while(true) {
Socket clientSocket = serverSock.accept();
PrintWriter writer = new PrintWriter(clientSocket.getOutputStream());
clientOutputStreams.add(writer);
Thread t = new Thread(new ClientHandler(clientSocket));
t.start();
System.out.println("got a connection");
}
// now if I get here I have a connection
}catch(Exception ex) {
ex.printStackTrace();
}
}
public void tellEveryone(String message) {
Iterator it = clientOutputStreams.iterator();
while(it.hasNext()) {
try {
PrintWriter writer = (PrintWriter) it.next();
writer.println(message);
writer.flush();
} catch(Exception ex) {
ex.printStackTrace();
}
} // end while
} // close tellEveryone
}
