panda.net.daytime.DaytimeTCPClient Maven / Gradle / Ivy

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package panda.net.daytime;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import panda.net.SocketClient;

/**
 * The DaytimeTCPClient class is a TCP implementation of a client for the Daytime protocol described
 * in RFC 867. To use the class, merely establish a connection with
 * {@link panda.net.SocketClient#connect connect } and call {@link #getTime getTime() } to retrieve
 * the daytime string, then call {@link panda.net.SocketClient#disconnect disconnect } to close the
 * connection properly.
 * 
 * @see DaytimeUDPClient
 */
public final class DaytimeTCPClient extends SocketClient {
	/** The default daytime port. It is set to 13 according to RFC 867. */
	public static final int DEFAULT_PORT = 13;

	// Received dates will likely be less than 64 characters.
	// This is a temporary buffer used while receiving data.
	private final char[] __buffer = new char[64];

	/**
	 * The default DaytimeTCPClient constructor. It merely sets the default port to
	 *  DEFAULT_PORT .
	 */
	public DaytimeTCPClient() {
		setDefaultPort(DEFAULT_PORT);
	}

	/**
	 * Retrieves the time string from the server and returns it. The server will have closed the
	 * connection at this point, so you should call {@link panda.net.SocketClient#disconnect
	 * disconnect } after calling this method. To retrieve another time, you must initiate another
	 * connection with {@link panda.net.SocketClient#connect connect } before calling
	 *  getTime()  again.
	 * 
	 * @return The time string retrieved from the server.
	 * @exception IOException If an error occurs while fetching the time string.
	 */
	public String getTime() throws IOException {
		int read;
		StringBuilder result = new StringBuilder(__buffer.length);
		BufferedReader reader;

		reader = new BufferedReader(new InputStreamReader(_input_, getCharsetName())); // Java 1.6
																						// can use
																						// getCharset()

		while (true) {
			read = reader.read(__buffer, 0, __buffer.length);
			if (read <= 0) {
				break;
			}
			result.append(__buffer, 0, read);
		}

		return result.toString();
	}

}