JNI jbyteArray

[Uli Kunkel]

I call c++ dll and somethimes I get ArrayIndexOutOfBounds Exception.
The error is in the c++ function, but I don't know where.
Here is the relevant c++ function code:

--------------------------------
jbyteArray result = env->NewByteArray(DataSize);
size_t i;

for (i=0; i < DataSize; ++i)
{
jbyte n = (signed char)m_Data;
env->SetByteArrayRegion(result, i,1, &n );
}

return result;
-------------------------------------
m_Data is unsigned char* type

Maybe the NewByteArray couldn't allocate more space..
Do I have to delete the jbyteArray variable somehow?
How do I do it if I have to return it to the java?


Any suggestions would be appretiated.

 

[Arne Vajhøj]

I call c++ dll and somethimes I get ArrayIndexOutOfBounds Exception.
The error is in the c++ function, but I don't know where.
Here is the relevant c++ function code:

--------------------------------
jbyteArray result = env->NewByteArray(DataSize);
size_t i;

for (i=0; i < DataSize; ++i)
{
jbyte n = (signed char)m_Data;
env->SetByteArrayRegion(result, i,1, &n );
}

return result;

The code looks good to me.

My guess is that the problem related to context
(code not shown).

Do I have to delete the jbyteArray variable somehow?
How do I do it if I have to return it to the java?

You can simply return it to Java and in that case
Java will make sure it gets GC'ed.

If you need to explicit free it in C++ then use
ReleaseByteArrayElements.

Arne

 

[Uli Kunkel]

I call c++ dll and somethimes I get ArrayIndexOutOfBounds Exception.
The error is in the c++ function, but I don't know where.
Here is the relevant c++ function code:

--------------------------------
jbyteArray result = env->NewByteArray(DataSize);
size_t i;

for (i=0; i < DataSize; ++i)
{
jbyte n = (signed char)m_Data;
env->SetByteArrayRegion(result, i,1, &n );
}

return result;

The code looks good to me.

My guess is that the problem related to context
(code not shown).

Do I have to delete the jbyteArray variable somehow?
How do I do it if I have to return it to the java?

You can simply return it to Java and in that case
Java will make sure it gets GC'ed.

If you need to explicit free it in C++ then use
ReleaseByteArrayElements.

Arne

Anyway I changed the code to copy all the data in one pass and now I
don't get an exception.
Also before when I set up to caught the exception the code continued to
work which means it wasn't a memory leak.