Synchronized Map vs Concurrent Hash Map: What's the Difference?

What is the difference between a synchronized map and a concurrent hash map?

A synchronized map is a thread-safe map that synchronizes access to its methods, while a concurrent hash map allows concurrent access without locking the entire map.

When should I use a synchronized map instead of a concurrent hash map?

Use a synchronized map when you need complete control over the access to the map and can afford the performance overhead. For high concurrency, a concurrent hash map is better.

Are there any performance implications of using one over the other?

Yes, synchronized maps can be slower due to locking, while concurrent hash maps are designed for high performance with multiple threads.

Can you give an example of when to use each?

Sure! Use a synchronized map for small data sets with low contention, and a concurrent hash map for large data sets accessed by many threads.