ReceiveString Returns Only the Immediately Available Data

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Demonstrates that Socket.ReceiveString returns only the text 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 ReceiveString 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.

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Socket;
import com.chilkatsoft.chilkat2.StringBuilder;

public class ChilkatExample {

    public static void main(String[] args) {
        Socket socket = new Socket();

        // Connect to chilkatsoft.com over TLS.
        boolean bTls = true;
        int maxWaitMs = 5000;
        try {
            socket.connect("chilkatsoft.com", 443, bTls, maxWaitMs);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        socket.setStringCharset("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 ReceiveString 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";
        String responseText;
        try {
            socket.sendString(httpReq);

            // Call ReceiveString a single time.  It returns only the text that is immediately available --
            // typically just the first network packet -- and does NOT wait for the entire response to arrive.
            responseText = socket.receiveString();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Load the received text into a StringBuilder so its length can be measured and the Content-Length
        // header extracted.  The Content-Length header gives the total size, in bytes, of the response body.
        StringBuilder sb = new StringBuilder();
        sb.append(responseText);
        String contentLength;
        try {
            contentLength = sb.getBetween("Content-Length: ", "\r\n");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Compare what this single ReceiveString returned against the full size of the expected response.
        // The received amount is only a small fraction of the total.
        System.out.println("Characters received so far (headers + partial body): " + sb.getLength());
        System.out.println("Expected response body size (Content-Length): " + contentLength + " bytes");

        // A single ReceiveString 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.
    }
}