about jar problem

[Vince Cheung]

How can i do to start program by commond line?
java -jar suncertify.jar server (Starting Server)
java -jar suncertify.jar client (Starting Client)

thanks

[Barend Garvelink]

You have to specify the main-class in the META-INF/MANIFEST.MF file inside the jar, when you do, the "java -jar" notation will work.

[Vince Cheung]

thank you, Barend. i will try

[Andrew Monkhouse]

Hi Vince,

The JavaRanch SCJD Reading Materials has two links you might be interested in.

Under the tutorials and whitepapers section ...

Distributing your Application as an executable JAR file http://www.cs.princeton.edu/introcs/85application/jar/jar.html

Sun's RMI Tutorial: http://java.sun.com/docs/books/tutorial/reallybigindex.html#rmi

The first one probably answers your question perfectly.

Regards, Andrew

[Vince Cheung]

I still can't do it, Can someone say how to do detailedly.
thank you

How can i do to start program by commond line?
java -jar suncertify.jar server (Starting Server)
java -jar suncertify.jar client (Starting Client)

[Isaac Shabtay]

Originally posted by Vince Cheung:
I still can't do it, Can someone say how to do detailedly.
thank you

Define the main class to be, say, "suncertify.Main". Then, in suncertify.Main, analyze the argument and invoke the appropriate functionality.

[Vince Cheung]

Should I put all classes(server and client) in a jar file or in two jar files(one is server and one is client)??

I have tried to put all classes in a jar file. But I can't start by two commond down.
java -jar suncertify.jar server (Starting Server)
java -jar suncertify.jar client (Starting Client)

I can only start one of two classes(Server, Client)

Manifest-Version: 1.0
Created-By: 1.4.2 (Sun Microsystems Inc.)
Main-Class: suncertify.server.ServerUI (or suncertify client.HotelMain)

How can I do, please give me some help, thanks

[Matt Sheehan.]

One jar. You must point to a class that can differentiate between your command line arguments and start the application in the correct mode.

public class Runner {
    public static void main(String[] args) {
        if (args[0].equals("server")) {
            // Start suncertify.server.ServerUI
        } else if (args[0].equals("client")) {
            // Start suncertify client.HotelMain
        }
    }
}

[Barend Garvelink]

Originally posted by Vince Cheung:
Should I put all classes(server and client) in a jar file or in two jar files(one is server and one is client)??

The instructions state that the entire application should be in a single file named runme.jar (not suncertify.jar! but check your instructions file to be sure).

Originally posted by Vince Cheung:
I have tried to put all classes in a jar file. But I can't start by two commond down.
java -jar suncertify.jar server (Starting Server)
java -jar suncertify.jar client (Starting Client)

I can only start one of two classes(Server, Client)


How can I do, please give me some help, thanks

Take a look at the signature of the main method:

public static void main(String[] args)

The key is in the "args" parameter. This will contain anything you type when starting the program (in this case: server or client).