CODEWITHSUNDEEP
javaclassserializationreflection
coder000001
coder000001

Reputation: 486

getDeclaredFields with actual runtime type, for Unsafe.objectFieldOffset(f)

getDeclaredFields[0].getType() is returning only the compile time class info. I have following code, where java.lang.reflect.Field's type is expected with actual type. This field is passed to Unsafe.objectFieldOffset(f)

public class Wrapper {
     public Object field1;
      //getters and setters for field1 and constructor
}
class SomeClass {

}
Wrapper wrapper = new Wrapper();
wrapper.field1 = new SomeClass();
System.out.println(wrapper.getClass().getDeclaredFields[0].getType());

Even though object is available with wrapper.field1.getClass(), Unsafe.objectFieldOffset(f) requires Field instance so wrapper.getClass().getDeclaredFields[0].getType() needs to return actual type which SomeClass instead of Object. Is there anyway I can override that behaviour ?

To rephrase, Is there anyway to use Unsafe.objectFieldOffset(f) with Runtime type info?

Upvotes: 1

Views: 357

Answers (1)

Cybran
Cybran

Reputation: 2313

Unfortunately, this will not be possible. getDeclaredFields() will do exactly that - return fields with compile-time information. You will have to retrieve the runtime type using field1.getClass().

Edit: You may also indirectly retrieve the class, using wrapper.getType().getDeclaredFields[0].get(wrapper).getClass();

Upvotes: 2

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