How to Handle ConcurrentModificationException with ConcurrentHashMap in Java 17?
I keep running into I'm trying to figure out I'm learning this framework and I tried several approaches but none seem to work. I'm working with a `ConcurrentModificationException` while trying to iterate over a `ConcurrentHashMap` in Java 17. I have a multi-threaded application where one thread is updating the map while another thread is reading from it. Here’s the relevant code snippet: ```java ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>(); // Writer thread new Thread(() -> { for (int i = 0; i < 100; i++) { map.put("key" + i, "value" + i); } }).start(); // Reader thread new Thread(() -> { for (String key : map.keySet()) { System.out.println(key + " -> " + map.get(key)); } }).start(); ``` I'm thinking the question arises because I'm using `keySet()` to iterate over the keys, which might not be thread-safe in this context. Although `ConcurrentHashMap` is designed for concurrent access, the iterator returned by `keySet()` can still throw `ConcurrentModificationException` when the map is modified during iteration. I've tried using `map.entrySet().iterator()` and explicitly handling concurrency with locks, but I’m not sure if that’s necessary or if the question lies elsewhere. Is there a recommended approach to safely iterate over a `ConcurrentHashMap` while it is being modified? What is the correct way to handle this in a multi-threaded setup? Any insights or best practices would be greatly appreciated! Any help would be greatly appreciated! I'm using Java LTS in this project. I'd be grateful for any help. Is there a better approach? This is happening in both development and production on CentOS. I'm open to any suggestions. The stack includes Java and several other technologies.