Java HotSpot Virtual Machine

Hello,

I've problem with calling JLabel's constructor with passing String value to constructor.

jobject jobjLabel;
jclass JLabelClass;
jmethodID mid;
JLabelClass = (*env)->FindClass(env,"javax/swing/JLabel");
  if(JLabelClass == NULL) {
	printf("Can't find class JLabel\n");
	goto destroy;
  }

  mid = (*env)->GetMethodID(env,JLabelClass,"<init>","(Ljava/lang/String;)V");
  jobjLabel = (*env)->NewObject(env,JLabelClass,mid,"Hello World");

At line:

 jobjLabel = (*env)->NewObject(env,JLabelClass,mid,"Hello World");

Main Thread exits with error code 1. I am sure that this line is true but I didn't find problem.

Are there any methods to find errors before program exit?