Armin Armin - 7 months ago 16
Java Question

Receive byte array from data with persian character

My code is a messenger that sends messages from an android device to another android device over WiFi.

Here's my code, in this class I send the message:

public class ClientThread extends Thread {

String address;
String message;
int portNum;
InetAddress serverAddr;
Socket socket;
PrintWriter out;
boolean broadcast;

public ClientThread(String addr, int port, String msg, boolean bcast) throws IOException {
address = addr;
portNum = port;
message = msg;
broadcast = bcast;
}

public void run() {
try {

ChatService.portsocket.setBroadcast(broadcast);
// Charset.forName("UTF-8").encode(message);
// Log.d("client",new String(message.getBytes()));
// byte[] b = EncodingUtils.getBytes(message,
// Charset.forName("UTF-8").name());
DatagramPacket packet1 = new DatagramPacket(message.getBytes(), message.length(),
InetAddress.getByName(address), 5555);
ChatService.portsocket.send(packet1);

}
catch (Exception e) {
e.printStackTrace();
}
}
}


and in this class I receive the message :

public class ChatService extends Service {

public static String serverIP;
public static int serverPort = 5555;
private ServerSocket serverSocket;
private serverThread sThread;
public static final String BROADCAST_ACTION = "UpdateEvent";
public static DatagramSocket portsocket;
Intent intent;
int i = 0;

@Override
public IBinder onBind(Intent arg0) {
return null;
}

private class serverThread extends Thread {

public void run() {
try {
serverIP = getLocalIpAddress();
Log.v("addr", serverIP);
if (serverIP != null) {
serverSocket = new ServerSocket(serverPort);
Log.v("socket", "created");
while (true) {
/*
* Socket client = serverSocket.accept();
* Log.v("client", "received");
*/
try {
byte [] buf = new byte [1024];
DatagramPacket packet = new DatagramPacket(buf, buf.length);
ChatService.portsocket.receive(packet);
byte [] result = new byte [packet.getLength()];
System.arraycopy(packet.getData(), 0, result, 0, packet.getLength());

String msg = new String(result);

Log.d("armin", msg);
updateGui(msg, packet.getAddress());

}
catch (Exception e) {
}
}
}
}
catch (Exception e) {
}
}
}
}


when I type for example آرمین and send it,the message the app receives is an incoherent word for example آر
anyone has idea to fix it ?

Answer

If you have a

String message = ...;

this is converted to a byte[]

byte[] bytes = message.getBytes();

then the DatagramPacket must be constructed using

new DatagramPacket(bytes, bytes.length(), ... );

Your call uses

new DatagramPacket( message.getBytes, message.length(),..,

but this uses the String length but Farsi requires more than one byte per character.

The string آرمین has 5 characters, but the UTF-8 encoding requires 10 bytes. You need to send 10 bytes.

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