Reading Java multidimensional array in C

Question

Hello friends.
Have searched the forum, but haven's found the answer.
I need to access a Java two dimensional array from C ( boolean[][] a; ).
Here's the code in C:
  jbooleanArray aArray; 
  jboolean **a;   
  fid=(*env)->GetFieldID(env, cls, "a", "[[Z"); 
  if (fid==0) { return; }  aArray=(*env)->GetObjectField(env, jobj, fid); 
  len=(*env)->GetArrayLength(env, aArray); 
  a=(jboolean **) (*env)->GetBooleanArrayElements(env, aArray, 0);Array lengths are correctly read separately. When I debug array in C it fails half-way or so:
  for (i=0;i<arows;i++)   
    for (j=0;j<acols;j++)      
      printf("a[%d][%d]=%u ",i,j,a<i>[j]);Error: An unexpected exception has been detected in native code outside the VM.
Unexpected Signal : EXCEPTION_ACCESS_VIOLATION (0xc0000005) occurred at PC=0x189217B4
Is it the correct way to read multidimensional array? Or could it be the problem with jboolean type?
Kev

Answer 1

Thank you for the idea to test an multidimensional array.
I testet the following code with C++ and changed it afterwords (untestet) into the syntax of C. Hope it runs.
boolean[][] is an array of Objects, this Objects are arrays of boolean!
#include "nativetest_BooleanArrayTest.h"
#include <stdio.h>
// without "if(blabla == 0) return;" etc.
JNIEXPORT void JNICALL Java_nativetest_BooleanArrayTest_test
  (JNIEnv * env, jobject obj)
   jsize i, j;
   jclass clazz = (*env)->GetObjectClass(env, obj);
   jfieldID fid = (*env)->GetFieldID(env, clazz, "b", "[[Z");
   jobject jobj = (*env)->GetObjectField(env, obj, fid);
   jobjectArray jarrRows = (jobjectArray)jobj;
   // Get elements of array
   jsize numberOfRows = (*env)->GetArrayLength(env, jarrRows);
   jboolean** carr = new jboolean*[numberOfRows];
   jbooleanArray* jrows = new jbooleanArray[numberOfRows];
   for (i = 0; i < numberOfRows; ++i) {
      jrows[i] = (*env)->GetObjectArrayElement(env, jarrRows, i);
      carr[i]  = (*env)->GetBooleanArrayElements(env, jrows, 0);
jsize numberOfColumns = (*env)->GetArrayLength(env, jrows[0]);
// test
for (i = 0; i < numberOfRows; ++i) {
for (j = 0; j < numberOfColumns; ++j) {
// printf ...
// release
for (i = 0; i < numberOfRows; ++i) {
(*env)->ReleaseBooleanArrayElements(env, jrows[i], carr[i], 0);
delete[] jrows;
delete[] carr;