Android™
Android™
Send a 4-byte Length Prefix over a Socket
See more Socket/SSL/TLS Examples
Demonstrates Socket.SendCount, which sends a four-byte length prefix in network byte order. This is typically used to tell the peer how many bytes follow.
Background. A length-prefixed framing scheme sends the byte count of a message before the message body, so the receiver knows exactly how many bytes to read with a counted receive.
Chilkat Android™ Downloads
// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;
import android.app.Activity;
import com.chilkatsoft.*;
import android.widget.TextView;
import android.os.Bundle;
public class SimpleActivity extends Activity {
private static final String TAG = "Chilkat";
// Called when the activity is first created.
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
boolean success = false;
CkSocket socket = new CkSocket();
// Connect to the server using TLS.
boolean bTls = true;
int maxWaitMs = 5000;
success = socket.Connect("example.com",5000,bTls,maxWaitMs);
if (success == false) {
Log.i(TAG, socket.lastErrorText());
return;
}
// Send a four-byte length prefix in network byte order. A common framing pattern is to send the
// number of bytes in a message before the message itself, so the peer knows exactly how many bytes
// to read.
int messageLength = 512;
success = socket.SendCount(messageLength);
if (success == false) {
Log.i(TAG, socket.lastErrorText());
return;
}
Log.i(TAG, "Length prefix sent.");
}
static {
System.loadLibrary("chilkat");
// Note: If the incorrect library name is passed to System.loadLibrary,
// then you will see the following error message at application startup:
//"The application <your-application-name> has stopped unexpectedly. Please try again."
}
}