JNI With Arrays

ArrayJNI.java

   1 class ArrayJNI{
   2         public native int getSum(int[] numbers);
   3         
   4         public static void main(String args[]){
   5                 System.loadLibrary("arraylib");
   6                 ArrayJNI arrjni=new ArrayJNI();
   7                 int intarr[]={12,32,43,13,54,5,-2};
   8                 int sum=arrjni.getSum(intarr);
   9                 System.out.println(sum);
  10         }
  11 }

ArrayJNI.h

   1 /* DO NOT EDIT THIS FILE - it is machine generated */
   2 #include <jni.h>
   3 /* Header for class ArrayJNI */
   4 
   5 #ifndef _Included_ArrayJNI
   6 #define _Included_ArrayJNI
   7 #ifdef __cplusplus
   8 extern "C" {
   9 #endif
  10 /*
  11  * Class:     ArrayJNI
  12  * Method:    getSum
  13  * Signature: ([I)I
  14  */
  15 JNIEXPORT jint JNICALL Java_ArrayJNI_getSum
  16   (JNIEnv *, jobject, jintArray);
  17 
  18 #ifdef __cplusplus
  19 }
  20 #endif
  21 #endif

ArrayJNI.cpp

   1 #include "ArrayJNI.h"
   2 
   3 
   4 JNIEXPORT jint JNICALL Java_ArrayJNI_getSum
   5   (JNIEnv *env, jobject obj, jintArray array){
   6         int i,sum=0;
   7         jsize len=env->GetArrayLength(array);
   8         jint *body=env->GetIntArrayElements(array,0);
   9         for(i=0;i<len;i++){
  10                 sum+=body[i];
  11         }
  12         env->ReleaseIntArrayElements(array,body,0);
  13         return sum;
  14   }

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