Re: gcj and cygnus

[Mark Kimsal <mark at kimsal dot com>]

Yeah, I know about the Main-Class attribute in the Manifest file, it's just
that my jars don't do anything when i double click them.
win32-JDK1.2.0,1.2.2,1.3rc1,1.3.0 or linux1.3.0

Cedric Berger wrote:

> mark kimsal wrote:
>
> > > There is basically 2 option for the "stupid user" using standard JDKs:
> > > - create an executable jar file. It's very simple to do, and the user
> > >   just has to double click on the file and it starts like an .exe.
> > >   no classpath to set-up.
> > >   It's plain simple to create but I'm amazed how few developer do it.
> > >   Of course, you need a java 2 runtime...
> >
> > I've never heard of an executable jar file, how do you create one?
>
> Basically, you add the following line to the manifest file of your
> jar file:
> Main-Class: com/tapinternet/niceapp/MainClass
>
> It works with both the JRE 1.2 or 1.3. there is also a mechanism
> for automatically downloading the needed extensions, but I've
> never used it.
>
> Cedric
>
> >From http://java.sun.com/j2se/1.3/docs/guide/jar/jarGuide.html:
>
>     On Win32 systems the Java 2 Runtime Environment's installation program
>     will register a default association for Jar files so that
> double-clicking a
>     Jar file on the desktop will automatically run it with javaw -jar.
>     Dependent extensions bundled with the application will also be loaded
>     automatically. This feature makes the end-user runtime environment
> easier
>     to use on Win32 systems.
>
>     The Solaris 2.6 kernel has already been extended to recognize the
> special
>     "magic" number that identifies a Jar file, and to invoke java -jar on
> such a
>     Jar file as if it were a native Solaris executable. A application
> packaged in
>     a Jar file can thus be executed directly from the command line or by
>     clicking an icon on the CDE desktop.
>
> from http://java.sun.com/j2se/1.3/docs/guide/jar/jar.html#Main Attributes:
>
>     attribute defined for stand-alone applications
>      This attribute is used by stand-alone applications that are bundled
> into
>     executable jar files which can be invoked by the java runtime directly
>     by running "java -jar x.jar".
>           Main-Class :
>           The value of this attribute defines the relative path of the main
>           application class which the launcher will load at startup time.
> The value
>           must not have the .class extension appended to the class name.