Subclassing a Class using ByteBuddy results in a class without any declared methods

Question

I'm missing something obvious here, but I don't see the declared methods when I subclass a Class using ByteBuddy.

Object.class.getDeclaredMethods()

result:

[protected void java.lang.Object.finalize() throws java.lang.Throwable, public final void java.lang.Object.wait(long,int) throws java.lang.InterruptedException, public final native void java.lang.Object.wait(long) throws java.lang.InterruptedException, public final void java.lang.Object.wait() throws java.lang.InterruptedException, public boolean java.lang.Object.equals(java.lang.Object), public java.lang.String java.lang.Object.toString(), public native int java.lang.Object.hashCode(), public final native java.lang.Class java.lang.Object.getClass(), protected native java.lang.Object java.lang.Object.clone() throws java.lang.CloneNotSupportedException, private static native void java.lang.Object.registerNatives(), public final native void java.lang.Object.notify(), public final native void java.lang.Object.notifyAll()]

Now using ByteBuddy:

new ByteBuddy().subclass(Object.class)
.make()
.load(getClass().getClassLoader(), ClassLoadingStrategy.Default.INJECTION)
.getLoaded().getDeclaredMethods()

result:

[]

Read the [Javadoc for `getDeclaredMethods()`](https://docs.oracle.com/javase/7/docs/api/java/lang/Class.html#getDeclaredMethods()): "excludes inherited methods". — Andy Turner, Jul 27 '16 at 20:51

score 1 · Accepted Answer · answered Jul 28 '16 at 15:11

As mentioned in the comments, getDeclaredMethods only returns the methods that are explicitly declared by a class. As you do not override any methods, there are zero such methods.

If you added an override for all methods, you would see them again (the non-final ones):

new ByteBuddy().subclass(Object.class)
  .method(any()).intercept(SuperMethodCall.INSTANCE)
  .make()
  .load(getClass().getClassLoader())
  .getLoaded()
  .getDeclaredMethods()

Alternatively, the reflection API offers getMethods() for finding all public virtual methods.

Subclassing a Class using ByteBuddy results in a class without any declared methods

1 Answers1