jni jnienv IsAssignableFrom example c c++ java

IsAssignableFrom

jboolean IsAssignableFrom(JNIEnv *env, jclass clazz1, jclass clazz2);

Determines whether an object of clazz1 can be safely cast to clazz2.

LINKAGE:

Index 11 in the JNIEnv interface function table.

PARAMETERS (of IsAssignableFrom)

env: the JNI interface pointer.

clazz1: the first class argument.

clazz2: the second class argument.

RETURNS of IsAssignableFrom

Returns JNI_TRUE if either of the following is true:

• The first and second class arguments refer to the same Java class.

• The first class is a subclass of the second class.

• The first class has the second class as one of its interfaces.

Example - IsAssignableFrom

{

jclass objCls = env->FindClass ("com/mycompany/myapp/exception/MyException");
jclass objThrowable = env->FindClass ("java/lang/Throwable");
if(env->IsAssignableFrom(objCls, objThrowable) == JNI_TRUE) { /* TRUE! */ }

}