componentMy.java: downloadable at the last page.

/*
A Simple Example--Authentication Component.
To Create a Component which works with the InterfaceServer,
the interface ComponentBase is required to be implemented.

interface ComponentBase is described in InterfaceServer.java.

*/

import java.io.*;

public class componentMy implements ComponentBase{

private final int init=0;
private final int success=1;
private final int failure=2;


private int state;

public componentMy(){
    state=init;
}

/* just a trivial example */

private void doAuthentication(String first,String last,String passwd){

if (first.equals("xin")&&last.equals("li")&&passwd.equals("xl123"))
    state=success;
else
    state=failure;
}

/* function in interface ComponentBase */

public KeyValueList processMsg(KeyValueList kvList){
    int MsgID=Integer.parseInt(kvList.getValue("MsgID"));
    if (MsgID!=0) return null;
    doAuthentication(kvList.getValue("FirstName"),kvList.getValue("LastName"),kvList.getValue("passwd"));
    KeyValueList kvResult = new KeyValueList();
    kvResult.addPair("MsgID","1");
    kvResult.addPair("Description","Authentication Result");

   switch (state) {
   case success: {
      kvResult.addPair("Authentication","success");
      break;
   }
  case failure: {
     kvResult.addPair("Authentication","failure");
     break;
   }
   }
  return kvResult;
}

}