I was asked


  • Handler
  • serializable, parcelable
  • Service, IntentService. What is inside?
  • Fragment, FragmentTransaction, commit. How does the commit method work? Is commit synchronized?
  • SynchronizationInter-process communication:  mutexes, semaphores, events, etc.
  • Collections in java
  • Memory leaks due to rotation with AsyncTask
  • RxJava
  • What is UI-thread, how does it work?
  • Loader
  • Which lifecycle methods of activity will be guaranteed invoked if OS destroys the one?

I was asked

Object methods

public native int hashCode();
public boolean equals(Object obj) {
  return (this == obj);
protected native Object clone() throws CloneNotSupportedException;
public String toString() {
  return getClass().getName() + "@" + Integer.toHexString(hashCode());
public final native void notify();
public final native void notifyAll();
public final native void wait(long timeout) throws InterruptedException;
protected void finalize() throws Throwable { }

ob1.Equals(ob2) --> ob1.hashcode == ob2.hashcode

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