A ConcurrentHashMap can be used as scalable frequency map (a form of histogram or multiset) by using LongAdder values and initializing via computeIfAbsent. For example, to add a count to a …

Oct 15, 2025 · In Java, the ConcurrentHashMap is a thread-safe implementation of the Map interface. It allows multiple threads to read and write data simultaneously, without the need for locking the entire …

Sep 7, 2024 · ConcurrentHashMap is the out-of-box ready ConcurrentMap implementation. For better performance, it consists of an array of nodes as table buckets (used to be table segments prior to …

Master Java’s ConcurrentMap and ConcurrentHashMap. Learn thread-safe map operations to build high-performance, concurrent applications.

Nov 12, 2025 · When dealing with multi-threaded programming in Java, one of the most common requirements is to have a thread-safe data structure for storing key - value pairs. The …

In this tutorial, we will learn about the Java ConcurrentHashMap class and its operations with the help of examples. The ConcurrentHashMap of the Java collections framework provides a thread-safe map.

This method should be used instead of size() because a ConcurrentHashMap may contain more mappings than can be represented as an int. The value returned is an estimate; the actual count may …

Jun 12, 2025 · Enter ConcurrentHashMap, Java’s tried-and-tested, thread-safe, high-performance alternative to HashMap. It’s not just a "safer" version — it’s optimized for real concurrency.

This tutorial will cover all methods of ConcurrentHashMap with examples and outputs, highlighting key points, use cases, best practices, performance.

Jul 23, 2025 · ConcurrentHashMap class obeys the same functional specification as HashTable and includes all the versions of methods corresponding to each method of a HashTable. A HashTable …