Memory Leak Discussion:

• Problem: Memory leaks are a silent killer in Java, especially in Android where memory is limited. They grow over time and can lead to performance issues and crashes.
• Causes: Examples include not closing open streams, using static fields to hold references, and using a HashSet with incorrect hashCode() or equals(). In Android, the object Context is often passed around and can cause leaks.
• Avoidance: Use WeakReferences and other reference types like SoftReferences. For example, in an Android AsyncTask, make the inner class static and use a WeakReference to the outer Activity to avoid memory leaks. Also, avoid using non-static inner classes in Activities, use Activity Context instead of Application Context, and never keep long-term references to any Context.

Reference Types in Java:

• Normal: The main type of reference. An object is collected when no longer used.
• Soft: Not strong enough to keep an object in memory during a garbage collection event. The garbage collector decides when to free the object memory.
• Weak: Weaker than SoftReferences.
• Phantom: The weakest reference; the object is eligible for finalization. This kind of reference is rarely used.