Server/client application

Question

i'm just starting to learn about server/client applications and i'm a little confused about actually implementing them.
my client will be an applet which can be accessed over the internet. i want the applet to be able to read/write to the server.
now my question is, how can i start up the server program?
i would want it to initialize and run, only when the user has gone to the website that uses the applet.

Answer 1

look at using a Servlet, running under Tomcat (download the Java Web Services Developer pack from java.sun.com
here's what the servlet looks like:
mport javax.servlet.*;
import java.util.*;
import java.net.*;
public class ServletTest extends GenericServlet
/** servlet is initialising */
public void init()
System.out.println("ServletTest initializing");
/** servlet wascalled bt client */
public void service(ServletRequest request,ServletResponse response)
try
byte[] data=new byte[100];
ServletInputStream inputStream=request.getInputStream();
int read=inputStream.read(data);
String string=URLDecoder.decode(new String(data,0,read),"UTF-8");
System.out.println("read "+read+" bytes: "+string);
inputStream.close();
ServletOutputStream outputStream=response.getOutputStream();
Date date=new Date();
outputStream.write(date.toString().getBytes());
outputStream.close();
catch(Exception ex)
ex.printStackTrace();
/** servlet is being destroyed */
public void destroy()
System.out.println("ServletTest terminating");
here's what the client looks like:
mport javax.servlet.*;
import java.util.*;
import java.net.*;
public class ServletTest extends GenericServlet
/** servlet is initialising */
public void init()
System.out.println("ServletTest initializing");
/** servlet wascalled bt client */
public void service(ServletRequest request,ServletResponse response)
try
byte[] data=new byte[100];
ServletInputStream inputStream=request.getInputStream();
int read=inputStream.read(data);
String string=URLDecoder.decode(new String(data,0,read),"UTF-8");
System.out.println("read "+read+" bytes: "+string);
inputStream.close();
ServletOutputStream outputStream=response.getOutputStream();
Date date=new Date();
outputStream.write(date.toString().getBytes());
outputStream.close();
catch(Exception ex)
ex.printStackTrace();
/** servlet is being destroyed */
public void destroy()
System.out.println("ServletTest terminating");