Re: Self-executing JAR

From:
Lew <lewbloch@gmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 16 Apr 2012 14:26:47 -0700 (PDT)
Message-ID:
<27365251.1727.1334611607107.JavaMail.geo-discussion-forums@pbcto7>
Tim Slattery wrote:

I have a very simple command-line program in Eclipse, just a
System.out.println("Hello World"). It runs just fine in the IDE. So I
use File|Export|Export, and select "Runnable JAR file". A JAR is
created.

And it doesn't work. I can double-click on it, or I can call it from a
command line. I get nothing. No "Hello world", no error message, no
nothing. What have I missed?


More info:
Here's the class:

public class Main {
    public static void main(String[] args)
    {
        System.out.println("Here I am!");
        try
        {
            SimpleDateFormat sdf = new
SimpleDateFormat("MM/dd/yyyy");
            sdf.setLenient(false);
            Date mydate = sdf.parse("2/29/1900");
            System.out.println("Good date: " + mydate.toString());
        }
        catch (ParseException ex)
        {
            System.out.println("ParseException: " +
ex.getMessage());
        }

    }

    /* (non-Java-doc)
     * @see java.lang.Object#Object()
     */
    public Main() {
        super();
    }

I export "Main.jar". To invoke from the command line, I type
"Main.jar". Nothing but a command prompt. I have jedit installed. If I
go to its directory and type "jedit.jar", it jumps right up. Therefore
I assume that the JRE can be found.


"Main.jar" is not an executable, so it won't execute unless you give it one:

  java -jar Main.jar

Show us the manifest, please?

Did you tell Windows to associate JAR files with the "java -jar" command, as "markspace" suggested?

What happens if you have a Word doc, say "foo.doc", and you type "foo.doc" at the command line?

--
Lew

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