How do you avoid ConcurrentModificationException when using iterators?
Table of Contents
- 1 How do you avoid ConcurrentModificationException when using iterators?
- 2 Why does iterator remove Do not throw ConcurrentModificationException?
- 3 How do you resolve ConcurrentModificationException?
- 4 How can we avoid ConcurrentModificationException in a single threaded environment?
- 5 How do I fix ConcurrentModificationException in Java?
- 6 Which of the following methods are provided by Spliterator interface?
- 7 What does iterator remove() do differently from list remove()?
- 8 Why are list iterator methods fail-fast?
How do you avoid ConcurrentModificationException when using iterators?
We can also avoid the Concurrent Modification Exception in a single threaded environment. We can use the remove() method of Iterator to remove the object from the underlying collection object. But in this case, you can remove only the same object and not any other object from the list.
Why does iterator remove Do not throw ConcurrentModificationException?
ConcurrentModificationException is not thrown by Iterator. remove() because that is the permitted way to modify an collection while iterating. This is what the javadoc for Iterator says: Removes from the underlying collection the last element returned by this iterator (optional operation).
How does ConcurrentHashMap avoid ConcurrentModificationException?
ConcurrentHashMap does not throw ConcurrentModificationException if the underlying collection is modified during an iteration is in progress. Iterators may not reflect the exact state of the collection if it is being modified concurrently. It may reflect the state when it was created and at some moment later.
Which method of the iterator throws ConcurrentModificationException?
If we invoke a sequence of methods on an object that violates its contract, then the object throws ConcurrentModificationException. For example: if while iterating over the collection, we directly try to modify that collection, then the given fail-fast iterator will throw this ConcurrentModificationException.
How do you resolve ConcurrentModificationException?
How do you fix Java’s ConcurrentModificationException? There are two basic approaches: Do not make any changes to a collection while an Iterator loops through it. If you can’t stop the underlying collection from being modified during iteration, create a clone of the target data structure and iterate through the clone.
How can we avoid ConcurrentModificationException in a single threaded environment?
To Avoid ConcurrentModificationException in single-threaded environment. You can use the iterator remove() function to remove the object from underlying collection object. But in this case, you can remove the same object and not any other object from the list.
How does ConcurrentHashMap works in Java?
ConcurrentHashMap class is thread-safe i.e. multiple threads can operate on a single object without any complications. In ConcurrentHashMap, the Object is divided into a number of segments according to the concurrency level. The default concurrency-level of ConcurrentHashMap is 16.
What causes ConcurrentModificationException?
The ConcurrentModificationException occurs when an object is tried to be modified concurrently when it is not permissible. This exception usually comes when one is working with Java Collection classes. For Example – It is not permissible for a thread to modify a Collection when some other thread is iterating over it.
How do I fix ConcurrentModificationException in Java?
Which of the following methods are provided by Spliterator interface?
Java Interface Spliterator Methods
| SN | Modifier & Type | Method |
|---|---|---|
| 1) | int | characteristics() |
| 2) | long | estimateSize() |
| 3) | default void | ForEachRemaining(Consumer action>) |
| 4) | default comparator | getComaparator() |
How do I resolve Java Util ConcurrentModificationException?
How to avoid ConcurrentModificationException in a multi-threaded environment?
- Instead of iterating over the collection class, we can iterate over the array.
- Another way can be locking the list by putting it in the synchronized block.
- JDK 1.5 or higher provides with ConcurrentHashMap and CopyOnWriteArrayList classes.
Why concurrentconcurrentmodificationexception is not thrown by iterator remove?
ConcurrentModificationException is not thrown by Iterator.remove () because that is the permitted way to modify an collection while iterating. This is what the javadoc for Iterator says: Removes from the underlying collection the last element returned by this iterator (optional operation). This method can be called only once per call to next ().
What does iterator remove() do differently from list remove()?
What does iterator.remove() do differently from list.remove(), so that iterator does not throw an exception and list.remove() does throw one? In the end, both are modifying the collection size.
Why are list iterator methods fail-fast?
The iterators returned by this class’s iterator and listIterator methods are fail-fast: if the list is structurally modified at any time after the iterator is created, in any way except through the iterator’s own remove or add methods, the iterator will throw a ConcurrentModificationException.
What is a ConcurrentModificationException in Java?
When you are working with collection objects, while one thread is iterating over a particular collection object, if you try to add or remove elements from it, a ConcurrentModificationException will be thrown.