What are the differences between thread-safe collections in Java?

What are the differences between thread-safe collections in Java?

Thread-safe collections in Java are designed to handle concurrent access. The main types include Vector, Hashtable, and the collections from the java.util.concurrent package like CopyOnWriteArrayList and ConcurrentHashMap.

Can you explain how ConcurrentHashMap works?

ConcurrentHashMap allows concurrent access by dividing the map into segments, allowing multiple threads to read and write without locking the entire map.

What are the advantages of using CopyOnWriteArrayList?

CopyOnWriteArrayList is great for scenarios with more reads than writes. It creates a new copy of the list on each write, ensuring that readers see a consistent view.

Are there any performance drawbacks to using these collections?

Yes, while they provide thread safety, they can introduce overhead. For example, CopyOnWriteArrayList can be inefficient for frequent writes due to the copying process.