NetworkClientTest.java Makes a simple connection to the host and port specified on the command line. Uses the following classes:
/** Make simple connection to host and port specified.
*
* Taken from Core Web Programming from
* Prentice Hall and Sun Microsystems Press,
* .
* © 2001 Marty Hall and Larry Brown;
* may be freely used or adapted.
*/
public class NetworkClientTest {
public static void main(String[] args) {
String host = "localhost";
int port = 8088;
if (args.length > 0) {
host = args[0];
}
if (args.length > 1) {
port = Integer.parseInt(args[1]);
}
NetworkClient nwClient = new NetworkClient(host, port);
nwClient.connect();
}
}
NetworkClient.java Starting point for a network client to communicate with a remote computer.
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.
*
* Taken from Core Web Programming from
* Prentice Hall and Sun Microsystems Press,
* .
* © 2001 Marty Hall and Larry Brown;
* may be freely used or adapted.
*/
public class NetworkClient {
protected String host;
protected int port;
/** Register host and port. The connection won't
* actually be established until you call
* connect.
*/
public NetworkClient(String host, int port) {
this.host = host;
this.port = port;
}
/** Establishes the connection, then passes the socket
* to handleConnection.
*/
public void connect() {
try {
Socket client = new Socket(host, port);
handleConnection(client);
} catch(UnknownHostException uhe) {
System.out.println("Unknown host: " + host);
uhe.printStackTrace();
} catch(IOException ioe) {
System.out.println("IOException: " + ioe);
ioe.printStackTrace();
}
}
/** This is the method you will override when
* making a network client for your task.
* The default version sends a single line
* ("Generic Network Client") to the server,
* reads one line of response, prints it, then exits.
*/
protected void handleConnection(Socket client)
throws IOException {
PrintWriter out = SocketUtil.getWriter(client);
BufferedReader in = SocketUtil.getReader(client);
out.println("Generic Network Client");
System.out.println
("Generic Network Client:\n" +
"Made connection to " + host +
" and got '" + in.readLine() + "' in response");
client.close();
}
/** The hostname of the server we're contacting. */
public String getHost() {
return(host);
}
/** The port connection will be made on. */
public int getPort() {
return(port);
}
}
SocketUtil.java Provides utilities for wrapping a BufferedReader around the Socket's input stream and a PrintWriter around the Socket's output stream
import java.net.*;
import java.io.*;
/** A shorthand way to create BufferedReaders and
* PrintWriters associated with a Socket.
*
* Taken from Core Web Programming from
* Prentice Hall and Sun Microsystems Press,
* .
* © 2001 Marty Hall and Larry Brown;
* may be freely used or adapted.
*/
public class SocketUtil {
/** Make a BufferedReader to get incoming data. */
public static BufferedReader getReader(Socket s)
throws IOException {
return(new BufferedReader(
new InputStreamReader(s.getInputStream())));
}
/** Make a PrintWriter to send outgoing data.
* This PrintWriter will automatically flush stream
* when println is called.
*/
public static PrintWriter getWriter(Socket s)
throws IOException {
// Second argument of true means autoflush.
return(new PrintWriter(s.getOutputStream(), true));
}
}
Aug 21