Get<PrimitiveType>ArrayElements Routines - GetIntArrayElements
NativeType
*Get<PrimitiveType>ArrayElements(JNIEnv *env,ArrayType array, jboolean *isCopy);
A family of functions that returns the body of the primitive array. The result is valid until the correspondingRelease
<PrimitiveType>ArrayElements() function is called. Since the returned array may be a copy of the Java array, changes made to the returned array will not necessarily be reflected in the original array until Release<PrimitiveType>ArrayElements() is called. (GetIntArrayElements)
If
isCopy is not NULL, then *isCopy is set to JNI_TRUE if a copy is made; or it is set to JNI_FALSE if no copy is made.
The following table describes the specific primitive array element accessors. You should make the following substitutions: (GetIntArrayElements)
- Replace Get<PrimitiveType>ArrayElements with one of the actual primitive element accessor routine names from the table.
- Replace ArrayType with the corresponding array type.
- Replace NativeType with the corresponding native type for that routine.
Regardless of how boolean arrays are represented in the Java VM,
GetBooleanArrayElements() always returns a pointer tojbooleans, with each byte denoting an element (the unpacked representation). All arrays of other types are guaranteed to be contiguous in memory.
Table 4-9a Get<PrimitiveType>ArrayElements Family of Accessor Routines
LINKAGE:
Indices in the JNIEnv interface function table.
Table 4-9b Get<PrimitiveType>ArrayElements Family of Accessor Routines
PARAMETERS of GetIntArrayElements
env: the JNI interface pointer.array: a Java string object.isCopy: a pointer to a boolean.RETURNS of GetIntArrayElements
Returns a pointer to the array elements, or
NULL if the operation fails.
Example of GetIntArrayElements
#include "TestJNI.h"
#include <stdio.h>
JNIEXPORT void JNICALL Java_TestJNI_intArray(JNIEnv *env, jobject obj, jintArray intArr)
{
jboolean isCp;
int i;
jsize len = (*env)->GetArrayLength(env, intArr);
jint *arr = (*env)->GetIntArrayElements(env, intArr, &isCp);
if(isCp == JNI_TRUE)
{
printf("isCopy: JNI_TRUE\n");
}
for(i = 0; i < len; i++)
{
arr[i] = 100 + i;
}
(*env)->ReleaseIntArrayElements(env, intArr, arr, 0);
}
