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2.10 WebClient: Talking to Web Servers Interactively

57

Listing 2.13 HttpClient.java (continued)

  private boolean checkHost(String host) {

    try {

      InetAddress.getByName(host);

      return(true);

    } catch(UnknownHostException uhe) {

      outputArea.setText("Bogus host: " + host);

      return(false);

    }

  }

}

NetworkClient

The 

NetworkClient

 class is a generic starting point for network clients and

is extended by 

HttpClient

. 

Listing 2.14 NetworkClient.java 

import java.net.*;  

import java.io.*;

/** A starting point for network clients. You'll need to

 *  override handleConnection, but in many cases

 *  connect can remain unchanged. It uses

 *  SocketUtil to simplify the creation of the

 *  PrintWriter and BufferedReader.

 *

 * @see SocketUtil

 */

public class NetworkClient {

  protected String host;

  protected int port;

  /** Register host and port. The connection won't

   *  actually be established until you call

   *  connect.

   *

   * @see #connect

   */

  public NetworkClient(String host, int port) {

    this.host = host;

    this.port = port;

  }

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