CODEWITHSUNDEEP
javajava-native-interfacenative-code
Phonon
Phonon

Reputation: 12727

JNI interface pointer confusion

I keep seeing the env interface pointer used with and without dereferencing, for example

env->DoSomething(arguments)

vs.

(*env)->DoSomething(env, arguments)

Are they actually different things? Is one from an older JNI implementation?

Upvotes: 1

Views: 267

Answers (2)

Denis Tulskiy
Denis Tulskiy

Reputation: 19177

It's the difference between writing jni code in C and C++, from wikipedia:

Note that C++ JNI code is syntactically slightly cleaner than C JNI code because like Java, C++ uses object method invocation semantics. That means that in C, the env parameter is dereferenced using (*env)-> and env has to be explicitly passed to JNIEnv methods. In C++, the env parameter is dereferenced using env-> and the env parameter is implicitly passed as part of the object method invocation semantics.

Upvotes: 2

Ernest Friedman-Hill
Ernest Friedman-Hill

Reputation: 81684

They're the same thing; just a little macro magic. The nicer (first) syntax is enabled in a C++ context.

Upvotes: 3

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