Method GetDirectBufferCapacity

JNI/jni/jni.h:1853–1855

        return functions->GetDirectBufferAddress(this, buf);
    }
    jlong GetDirectBufferCapacity(jobject buf) {
        return functions->GetDirectBufferCapacity(this, buf);
    }
    jobjectRefType GetObjectRefType(jobject obj) {
        return functions->GetObjectRefType(this, obj);
    }