Which thread-safe container is most suitable for read-mostly operations?

For read-preference operations in Java, the most suitable class is CopyOnWriteArrayList from the java.util.concurrent package.

This thread-safe container implements a copying strategy for the array on each write operation, making reads very fast and non-blocking, as reads work with an immutable copy of the data.

Example of usage:

import java.util.concurrent.CopyOnWriteArrayList;

CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>();
list.add("element1");
list.add("element2");

// Multiple threads can safely read the list without locks
for (String item : list) {
    System.out.println(item);
}

// Write (add) will create a copy of the array
list.add("element3");

Thus, CopyOnWriteArrayList is optimal when read operations significantly outnumber write operations.