Thread: Help required in creating header file using java

Hi All,
May i know how to create c header file using java jni for a class which is inside a jar file.
I have created a jar called HelloWorld.jar (using Netbeans) which has only class file as below

package example;

public class HelloWorld {
public native void print(); //native method
static //static initializer code
{
System.loadLibrary("CLibHelloWorld");
}

public static void main(String[] args)
{
HelloWorld hw = new HelloWorld();
hw.print();
}
}
i tried following command
javah -jni HelloWorld
i am getting below error
error: cannot access HelloWorld
class file for HelloWorld not found
javah -jni example.HelloWorld
i am getting below error
error: cannot access HelloWorld
class file for HelloWorld not found

Please let me know how to create the c header file.

Originally Posted by Norm

What have you tried with classpath?

No i havent tried... May i know how to do that?

Originally Posted by Norm

Read the doc for the javah command.

Why put the class in a jar file? Try working with the class outside of the jar file.

I just given an example, actual scenario is different. Jar will do other functionality too...

Originally Posted by Norm

What happens when the class file is not in a jar file?


The answer could depend on the actual scenario.

The jar has other functionality of large project which i cant mention here sorry. but i cant grantee this HelloWorld class is not dependent on other class and its functionality already clearly mentioned in my first post.

Step 1:

Say I have a folder in my desktop named as "example".
Inside it,I copy paste your code.

ScreenShot1.jpg

Step 2:
Compile the Java Code.

2.jpg

Step 3:
Generate header file from java class
Note: You need to run javah from the directory containing example/HelloWorld.class

3.png


You will find a "example_HelloWorld.h" being created/generated at the Desktop.

Untitled.jpg


Cheers
Sandeep