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passing java object to c through jni

Posted on 2016-10-27
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Last Modified: 2016-11-28
public class DemoStructurepass {
public int a;
public int b;
public int c;
public int d;
}
public class MainActivity extends Activity {
test clsObj ;
DemoStructurepass dss;
long iS;


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

dss = new DemoStructurepass();
clsObj = new test();
iS = clsObj.functionAddcheck(dss);
// public native long functionAddcheck(DemoStructurepass dss);
}
}

Now I need to access the DemoStructurepass structure in JNI(C)
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Question by:rr rrrrrr
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2 Comments
 
LVL 28

Accepted Solution

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dpearson earned 2000 total points
ID: 41866314
JNI is a tricky thing to deal with.

I'd suggest taking an existing tutorial (e.g. http://www.ibm.com/developerworks/java/tutorials/j-jni/j-jni.html), going through all of the steps in that tutorial to make sure you have it all working.

Then modify the tutorial code to match your actual Java code.

If you're going to be writing a lot of JNI code (not just passing one object around), I'd strongly suggest looking at a toolkit like SWIG (http://www.swig.org/) which is designed to help write wrappers in various languages to go around C/C++ code.  So for this approach, you'd write the C++ code first and then generate a wrapper to access it from Java (and then hook your actual Java code to that wrapper).

Good luck!

Doug
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Expert Comment

by:frankhelk
ID: 41903911
No comment has been added to this question in more than 21 days, so it is now classified as abandoned.

I have recommended this question be closed as follows:

Accept: dpearson (https:#a41866314)

If you feel this question should be closed differently, post an objection and the moderators will review all objections and close it as they feel fit. If no one objects, this question will be closed automatically the way described above.

frankhelk
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