Run the .jar file

[gaya3]

Hi all,
When i try to run the .jar file,the following error is thrown.
"Failed to load Main-Class manifest attribute from"
How could i correct the above error.
As i'm very much new to this jar file creation.I tired with
following sample
jar cf sample1.jar GetIP.class
and just i run the .jar as
java -jar sample1.jar

is that rite are something else need to follow?
correct me if i'm wrong.

-Thanks & Regards,
Hamsa

[JosAH]

Hi all,
When i try to run the .jar file,the following error is thrown.
"Failed to load Main-Class manifest attribute from"
How could i correct the above error.
As i'm very much new to this jar file creation.I tired with
following sample
jar cf sample1.jar GetIP.class
and just i run the .jar as
java -jar sample1.jar

is that rite are something else need to follow?
correct me if i'm wrong.

-Thanks & Regards,
Hamsa

How is the JVM supposed to know which class it has to use for startup? (of course
that class has to have a static void main(String[] args) method defined. The JVM
isn't that smart to figure out: "hm, this jar contains only one class, lets use that
one for startup". You need a proper manifest entry in your jar file; go and read
a tutorial about it.

kind regards,

Jos

[r035198x]

... go and read
a tutorial about it.

kind regards,

Jos

This one.

[gaya3]

How is the JVM supposed to know which class it has to use for startup? (of course
that class has to have a static void main(String[] args) method defined. The JVM
isn't that smart to figure out: "hm, this jar contains only one class, lets use that
one for startup". You need a proper manifest entry in your jar file; go and read
a tutorial about it.

kind regards,

Jos

Thank u Jos. It works fine.:-)

-Thanks & regards,
Hamsa

[gaya3]

How is the JVM supposed to know which class it has to use for startup? (of course
that class has to have a static void main(String[] args) method defined. The JVM
isn't that smart to figure out: "hm, this jar contains only one class, lets use that
one for startup". You need a proper manifest entry in your jar file; go and read
a tutorial about it.

kind regards,

Jos

Jos.. one more doubt..
In my jar file named Myjar having the following contents..
under MyPackage

--> MyClass
--> Image file (bmp)

"MyClass" takes "Image file" as input and produce another "Image file" (bmp)as output.
I want to write that output of that "MyClass" to the "Myjar".
How can we do that?is there any possibility?

-Thanks & Regards,
Hamsa

[JosAH]

Jos.. one more doubt..
In my jar file named Myjar having the following contents..
under MyPackage

--> MyClass
--> Image file (bmp)

"MyClass" takes "Image file" as input and produce another "Image file" (bmp)as output.
I want to write that output of that "MyClass" to the "Myjar".
How can we do that?is there any possibility?

-Thanks & Regards,
Hamsa

Have a look at the classes JarFile, JarInputStream, JarOutputStream and the
parent class ZipFile and its compadres; a .jar file is basically not for writing to
it. In you case better create a new .jar file with that class and .bmp file, it's
a one-time operation anyway. If you want database (e.g. writable) functionality
you know where to find them.

kind regards,

Jos