Can you give examples of collection data structures that ensure thread safety?

In Java, there are several collections that provide thread safety:

• Vector — a thread-safe version of ArrayList, with all methods synchronized.
• Hashtable — a thread-safe version of HashMap.
• Collections from the java.util.concurrent package:
  • ConcurrentHashMap — a high-performance thread-safe hash table.
  • CopyOnWriteArrayList — a thread-safe list, optimal for scenarios with frequent reads and infrequent modifications.
  • BlockingQueue and its implementations (LinkedBlockingQueue, ArrayBlockingQueue) — thread-safe queues with blocking operations.

Example of using ConcurrentHashMap:

ConcurrentHashMap<String, Integer> map = new ConcurrentHashMap<>();
map.put("key", 1);
Integer value = map.get("key");

These structures allow safe working with collections from multiple threads without external synchronization.