JAR! . . .What is it good for?. . .Absolutely nothing :-)

Hi,

Well not quite; actually love JAR files, but why does the AppletViewer (W2K
SUN JDK "something", at least) insist on asking for the .CLASS file *as well
as* the .JAR file?

Is this *all* applet viewers? *all* html? or just something *my* code is
doing?

Also why are there no hits on "noclassdeffounderror" on SUN's website?

In the attached *very short* code snippet, the EmpApplet class is attempting
to invoke methods in the EmpClient class that has been built into the same
JAR file, but the only Typing that I can see (sorry not my code, but I'm
told this works on UNIX browsers) is: -

    EmpClient client;

I'm guessing that this declares "client" as an instance of the EmpClient
class, but doesn't EmpClient have to be Imported or something? Either way,
EmpClient is not "inited" and the -debug gives me the noclassdeffounderror
and the browser makes no attempt to load EmpClient from the codebase.

So, how does one define a class? import?

Yes, I will google tomorrow but it's late and I'm old. . .

Regards Richard Maher

PS. Sorry for the school boy questions, but I honestly am RTFMing as well.

EmpClient Class
===========

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;

public class EmpClient {
 public static final String HOSTCHARSET="ISO-8859-1";
 public static final byte [] CRLF = {'\r','\n'};
 private Socket socket;
 private String host;
 private int port;
 private BufferedReader in;
 private OutputStream out;

 public class Message
 {
  String type;
  String message;
  Message (String type , String message)
  {
   this.type = type;
   this.message = message;
  }
  public String getMessage()
  {
   return message;
  }
  public String getType()
  {
   return type;
  }

 }
 EmpClient (String host , int port)
 {
  this.host = host;
  this.port = port;
 }

 public void open () throws UnknownHostException, IOException
 {
  socket = new Socket (InetAddress.getByName(host) , port);
  in = new BufferedReader (new InputStreamReader (socket.getInputStream() ,
HOSTCHARSET));
  out = new BufferedOutputStream (socket.getOutputStream());
 }

 public void close () throws IOException
 {
  try {
   sendMessage ("99","");
  } catch (IOException e) {
   // close in any situation!
  }
  socket.close();
 }

 public void sendMessage (String type , String message) throws IOException
 {
  byte [] msgtype = type.getBytes(HOSTCHARSET);
  byte [] msg = message.getBytes(HOSTCHARSET);

  out.write(msgtype);
  out.write(msg);
  out.write(CRLF);
  out.flush();
 }
 public Message readMessage () throws IOException
 {
  String wholemsg = in.readLine();

  String type = wholemsg.substring(0,2);
  String msg = wholemsg.substring(2);
  return new Message (type , msg);
 }
 public void initEmployeeRead (String employee) throws IOException
 {
  sendMessage ("20" , employee);
 }
 public String readNextEmployee () throws IOException
 {
  Message msg = readMessage ();
  if (msg.getType().equals("21"))
   return msg.getMessage().trim();
  return null;
 }
}

EmpApplet Class
============

import java.applet.Applet;
import java.io.IOException;

public class EmpApplet extends Applet {
    EmpClient client;

 public void init ()
 {
  String host = getParameter("HOST");
  int port = Integer.parseInt(getParameter ("PORT"));
  client = new EmpClient (host , port);
  try {
   client.open();
  } catch (Exception e) {
   client = null;
  }
 }
 public String initEmployee (String employee)
 {
  try {
   client.initEmployeeRead(employee);
   return null;
  } catch (IOException e) {
   return e.getMessage();
  }
 }
 public String nextEmployee ()
 {
  try {
   return client.readNextEmployee();
  } catch (IOException e) {
   return null;
  }
 }
 public void destroy() {
  try {
   client.close();
  } catch (IOException e) {
  }
  super.destroy();
 }
}