ReceiveSb Returns Only the Immediately Available Data

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Demonstrates that Socket.ReceiveSb returns only the data immediately available and not the entire response. The example connects to chilkatsoft.com over TLS and requests big_helloWorld.txt, a large text file of roughly 74,000 lines. A single ReceiveSb call returns just the first portion of the response, and the example reports how many characters were received compared with the total size given by the response Content-Length header.

// 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 chilkatsoft.com over TLS.
    boolean bTls = true;
    int maxWaitMs = 5000;
    success = socket.Connect("chilkatsoft.com",443,bTls,maxWaitMs);
    if (success == false) {
        Log.i(TAG, socket.lastErrorText());
        return;
        }

    socket.put_StringCharset("utf-8");

    //  Send an HTTP GET request for big_helloWorld.txt, a large text file of roughly 74,000 lines of
    //  "Hello World!".  This uses a minimal HTTP request only to exercise ReceiveSb against a public
    //  server -- for real HTTP work, use the Chilkat Http, Rest, or HttpCurl classes instead.
    String httpReq = "GET /big_helloWorld.txt HTTP/1.1\r\nHost: chilkatsoft.com\r\nConnection: close\r\n\r\n";
    success = socket.SendString(httpReq);
    if (success == false) {
        Log.i(TAG, socket.lastErrorText());
        return;
        }

    //  Call ReceiveSb a single time.  It returns only the bytes that are immediately available --
    //  typically just the first network packet -- and does NOT wait for the entire response to arrive.
    CkStringBuilder sb = new CkStringBuilder();
    success = socket.ReceiveSb(sb);
    if (success == false) {
        Log.i(TAG, socket.lastErrorText());
        return;
        }

    //  The response begins with HTTP headers.  The Content-Length header gives the total size, in bytes,
    //  of the response body.
    String contentLength = sb.getBetween("Content-Length: ","\r\n");
    if (sb.get_LastMethodSuccess() == false) {
        Log.i(TAG, sb.lastErrorText());
        return;
        }

    //  Compare what this single ReceiveSb returned against the full size of the expected response.  The
    //  received amount is only a small fraction of the total.
    Log.i(TAG, "Characters received so far (headers + partial body): " + String.valueOf(sb.get_Length()));
    Log.i(TAG, "Expected response body size (Content-Length): " + contentLength + " bytes");

    //  A single ReceiveSb call returns whatever is currently available, so it cannot indicate whether the
    //  full response has arrived.  This makes it difficult to know when a response is complete: the
    //  application must either know how many bytes to expect (for example from a Content-Length header or
    //  an application-defined length prefix) and keep receiving until that many bytes are collected, or
    //  keep receiving until the peer closes the connection.

  }

  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."
  }
}