What are Java Collections and how do they handle concurrency?

What are Java Collections and how do they handle concurrency?

Java Collections are data structures that store groups of objects. They include lists, sets, and maps. Concurrency in Java Collections refers to how these structures can be accessed and modified by multiple threads simultaneously without causing data inconsistency.

Can you explain the differences between synchronized and concurrent collections?

Synchronized collections are thread-safe but can lead to performance bottlenecks due to locking. Concurrent collections, like ConcurrentHashMap, allow for higher concurrency by using finer-grained locking or lock-free algorithms.

When should I use concurrent collections over synchronized collections?

Use concurrent collections when you expect high levels of concurrent access and need better performance. Synchronized collections are simpler but can slow down your application under heavy load.

What are some examples of concurrent collections in Java?

Examples include ConcurrentHashMap, CopyOnWriteArrayList, and BlockingQueue. These are designed to handle concurrent access efficiently.