Access Java Class Variables from NDK

Access Java class variables from NDK (non-static function) in C:

• env and obj are the first two parameters of the NDK function
• "Ljava/lang/String;" is called the field descriptor of type String

Field Descriptor of other Variable Types:

• Remember the semi-colon
• Replace "Get" by "Set" for Set Field Functions

Field Descriptor	Type	Get Field Function
Z	boolean	GetBooleanField
B	byte	GetByteField
C	char	GetCharField
S	short	GetShortField
I	int	GetIntField
J	long	GetLongField
F	float	GetFloatField
D	double	GetDoubleField
Ljava/lang/String;	String	GetObjectField
[I	int[]	GetObjectField, and then cast it to an array jintArray *arr = reinterpret_cast<jintArray*>(&data);
[Ljava/lang/Object;	object[]	GetObjectField, and then cast it to an array