jni jnienv NewIntArray example c c++ java

New<PrimitiveType>Array Routines - NewIntArray

ArrayType New<PrimitiveType>Array(JNIEnv *env, jsize length);

A family of operations used to construct a new primitive array object. Table 4-8 describes the specific primitive array constructors. You should replace New<PrimitiveType>Array with one of the actual primitive array constructor routine names from the following table, and replace ArrayType with the corresponding array type for that routine.(NewIntArray)

Table 4-8a New<PrimitiveType>Array Family of Array Constructors

New<PrimitiveType>Array Routines	Array Type
NewBooleanArray()	jbooleanArray
NewByteArray()	jbyteArray
NewCharArray()	jcharArray
NewShortArray()	jshortArray
NewIntArray()	jintArray
NewLongArray()	jlongArray
NewFloatArray()	jfloatArray
NewDoubleArray()	jdoubleArray

LINKAGE:

Indices in the JNIEnv interface function table.

Table 4-8b New<PrimitiveType>Array Family of Array Constructors

New<PrimitiveType>Array Routines	Index
NewBooleanArray()	175
NewByteArray()	176
NewCharArray()	177
NewShortArray()	178
NewIntArray()	179
NewLongArray()	180
NewFloatArray()	181
NewDoubleArray()	182

PARAMETERS of NewIntArray

env: the JNI interface pointer.

length: the array length.

RETURNS of NewIntArray

Returns a Java array, or NULL if the array cannot be constructed.

Example of NewIntArray

JNIEXPORT jintArray JNICALL Java_ArrayTest_initIntArray(JNIEnv *env, jclass cls, int size)
{
 jintArray result;
 result = (*env)->NewIntArray(env, size);
 if (result == NULL) {
     return NULL; /* out of memory error thrown */
 }
 int i;
 // fill a temp structure to use to populate the java int array
 jint fill[256];
 for (i = 0; i < size; i++) {
     fill[i] = 0; // put whatever logic you want to populate the values here.
 }
 // move from the temp structure to the java structure
 (*env)->SetIntArrayRegion(env, result, 0, size, fill);
 return result;
}