Kbase 19839: Java Program to Test RMI Calls
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
24/09/2008 |
|
Status: Verified
GOAL:
Test programs to confirm that the Java RMI mechanism is working.
FACT(s) (Environment):
Progress 9.x
FIX:
Steps to run the test:
1) Save the first piece of code below as a file named
"PSCTest.java".
2) Save the second piece of code below as a file named
"RMITestServer.java".
3) Set your path to include your Java compiler (javac).
4) javac PSCTest.java
5) javac RMITestServer.java
6) rmic RMITestServer
7) rmiregistry &
8) java RMITestServer
This should print: RMIServer is ready to take your requests.
9) Open another session and run the client. The client will take
the following commands:
time - display the current time
author - display the program's author
10) java PSCTest\$Client time
This should print:
The current date and time is Wed May 31 12:48:42 EDT 2000
11) java PSCTest\$Client author
This should print:
This program was written by Progress Technical Support
To clean up, do a ps -ef|grep <yourlogin> and look for rmiregistry.
There may be another process running that is running something
called RegistryImpl. This is a subprocess of the process running
rmiregistry. Do a kill -1 on the subprocess, and the rmiregistry
should shut down also. Otherwise, just do a kill -1 on the
rmiregistry process.
/*********PSCTest.java:*************/
import java.rmi.*;
/**
* This class is a placeholder that simply contains other classes.
**/
public class PSCTest {
/**
* This is the interface that defines the exported methods of the
* server.
**/
public interface RMITest extends Remote {
/** Get the current time */
public String getDateTime()
throws RemoteException, RMITestException;
/** Get the program's author */
public String getAuthor()
throws RemoteException, RMITestException;
}
/**
* This is a type of exception used to represent exceptional
* conditions.
**/
public static class RMITestException extends Exception {
public RMITestException(String msg) { super(msg); }
}
/**
* This class is a simple stand-alone client program that interacts
* with a RMITest server. It invokes different methods depending on
* its command-line arguments.
**/
public static class Client {
public static void main(String[] args) {
try {
// Set the standard RMI security manager so that we can
// safely load untrusted rmitest stub code over the network.
System.setSecurityManager(new RMISecurityManager());
// Figure out what server to connect to by reading a system
// property (specified on the command line with a -D option
// to java) or, if it is not defined, use a default URL.
// Note that by default this client tries to connect to a
// server on the local machine
String url = System.getProperty("rmiserver",
"rmi:///RMIServer");
// Now look up that server using the Naming object, which
// contacts the rmiregistry server. Given the url, this call
// returns a rmiserver object whose methods may be invoked
// remotely
RMITest myTest = (RMITest) Naming.lookup(url);
// Convert the user's command to lower case
String cmd = args[0].toLowerCase();
// Now, go test the command against the options
if (cmd.equals("time")) { // Show the time
System.out.println("The current date and time is " +
myTest.getDateTime());
}
else if (cmd.equals("author")) { // Show the program author
S.ystem.out.println(myTest.getAuthor());
}
else {
System.out.println("Unknown command");
System.err.println("Usage: java [-Dserver=<url>] PSC$Client
<command>");
System.err.println("where command is: time, author");
}
}
// Catch and display RMI exceptions
catch (RemoteException e) {System.err.println(e);}
// Catch and display any related exceptions
catch (RMITestException e) {System.err.println(e.getMessage());}
// Other exceptions are probably user syntax errors,
//so show usage.
catch (Exception e) {
System.err.println(e);
System.out.println("Unknown command");
System.err.println("Usage: java [-Dserver=<url>] PSC$Client
<command>");
System.err.println("where command is: time, author");
}
}
}
}
/**************RMITestServer.java:*****************/
import java.rmi.*;
import java.rmi.server.*;
import java.util.*;
import PSCTest.*;
/**
* This class implements the remote methods defined by the PSCTest
* interface.
**/
public class RMITestServer extends UnicastRemoteObject implements
RMITest
{
/**
* This constructor doesn't do anything, but because it throws
* the same exception that the superclass constructor throws, it
* must be declared.
**/
public RMITestServer() throws RemoteException { super(); }
/**
* Show the current system time.
*
* This method is synchronized to make it thread safe, since it
* manipulates the accounts hashtable.
**/
public synchronized String getDateTime()
throws RemoteException, RMITestException {
String currentTime = new Date().toString();
return currentTime;
}
/**
* Show the program's author.
*
* This method is synchronized to make it thread safe, since it
* manipulates the accounts hashtable.
**/
public synchronized String getAuthor()
throws RemoteException, RMITestException {
String author =
"This program was written by Progress Technical Support";
return author;
}
/**
* The main program that runs this RMITestServer.
*
* Create a RMITestServer object and give it a name in the registry.
* Read a system property to determine the name, but use "RMIServer"
* as the default name. This is all that is necessary to set up the
* service. RMI takes care of the rest.
**/
public static void main(String[] args) {
try {
// Create a server object
RMITestServer myServer = new RMITestServer();
// Figure out what to name it
String name = System.getProperty("server", "RMIServer");
// Name it that
Naming.rebind(name, myServer);
// Tell the world we're up and running
System.out.println(name + " is ready to take your requests.");
}
catch (Exception e) {
System.err.println(e);
System.err.println("Usage: java [-Dserver=<name>]
RMITestServer");
System.exit(1); // Force an exit because there might
// be other threads
}
}
}
.