How to Create Immutable Map in Java?
Learn to create an immutable or unmodifiable Map using the factory methods added in Java 9 and other versions (Java 8 to Java 21) with examples.
Java collections framework is a unified architecture for representing and manipulating collections. All collections frameworks contain the following:
Interfaces: These are abstract data types that represent collections. Interfaces allow collections to be manipulated independently of the details of their representation. In object-oriented languages, interfaces generally form a hierarchy.
Implementations, i.e., Classes: These are the concrete implementations of the collection interfaces. In essence, they are reusable data structures.
Algorithms: These are the methods that perform useful computations, such as searching and sorting, on objects that implement collection interfaces. The algorithms are said to be polymorphic: that is, the same method can be used on many different implementations of the appropriate collection interface.
In addition to collections, the framework defines several map interfaces and classes. Maps store key/value pairs. Although maps are not collections in the proper use of the term, but they are fully integrated with collections.
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Tutorials
Java HashMap Initialization (Load Factor and Initial Capacity)
Learn to initialize Java HashMap object in different ways such as empty map, pre-populated map, and collecting stream elements into the map.
Java Enumeration, Iterator, ListIterator and Spliterator
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Java ArrayList Length and Size
Java ArrayList does not publicly expose the length of the backing array, and only the count of the stored elements can be retrieved using its size() method.
Java ArrayList Sort: Ascending and Descending Order
Learn to sort Java ArrayList in ascending and descending order using ArrayList.sort(), Collections.sort(), Comparator interface and Java 8 Streams.
Java Map computeIfAbsent()
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Java ConcurrentSkipListMap
Learn the Java ConcurrentSkipListMap and the major differences between ConcurrentSkipListMap and other Map implementations.
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Learn to find the minimum value and the maximum value in a Map using Steam API, Collections API and simple comparison using iteration.
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Comparing two Java lists with order ignored is a common requirement during JUnit tests where both lists come from different sources.
Java UnsupportedOperationException
Java UnsupportedOperationException is an unchecked exception and occurs when a requested operation is not supported in a class.
Create and Initialize List with Values in One Line
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Java ArrayDeque with Examples
Learn about Java ArrayDeque and its features with practical examples. Learn to use it as Stack and Queue, and the difference from LinkedList.
Java SynchronousQueue with Example
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Java Queue: From Fundamentals to Mastery
Learn Queue data structure and the Java Queue interface and implementations with practical examples such as LinkedList, PriorityQueue and ArrayDeque.
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Learn to convert Map keys and values to the array, List or Set using the ArrayList and HashSet constructors as well as Stream APIs.
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Learn to remove all the occurrences of an element from a given List using Java loops, list methods and Stream API.
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Learn to convert a List to a Map in Java using Streams, Commons collections, and Guava including Multimap class for duplicate list items.
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Learn to create a List from array using Arrays.asList(array) and new ArrayList(Arrays.asList(array). Learn their differences with examples.
Inverting a Map In Java
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Java Collections.synchronizedMap() vs ConcurrentHashMap
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Complete Guide to Java HashMap (with Examples)
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Intoduction to Java Collections
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Java Collection Tutorials
This Java guide will take us through Java Collections framework. We will understand the core concepts and performing the basic operations.
Java ArrayList: A Comprehensive Guide for Beginners
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Java List
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Java Map
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Java EnumMap with Examples
Learn to create and work with the Java EnumMap in detail, difference between EnumMap and HashMap and the practical usecases for the same.
Java Nested Map with Examples
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Java Immutable Vs. Unmodifiable Map: What’s Difference?
Learn to create immutable and unmodifiable maps in Java using Java collections APIs and Guava’s ImmutableMap class.
Collecting Stream Elements into Immutable Collection
Learn to convert a Stream into immutable/unmodifiable collection using Stream methods such as stream() and Collectors.toUnmodifiableList().
Java TreeMap vs HashMap
Learn the differences between TreeMap and HashMap in Java as both implements the Map interface but differ in functionality and performance.
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Learn to use BlockingQueue drainTo() method for draining the queue items (polling all or specific number of elements) into a Collection.
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Guide to Java ConcurrentMap
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Guide to Java WeakHashMap
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Java CopyOnWriteArraySet class
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Java CopyOnWriteArrayList class
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Java TransferQueue Vs. LinkedTransferQueue
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Java ArrayBlockingQueue class
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Java PriorityBlockingQueue class
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Java Priority Queue (+ Comparator Example)
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Java Spliterator (with Examples)
Unlike traditional iterators, Spliterator is designed with parallelism in mind and mainly helps in parallel processing when the collection or stream has a large number of elements.
Java ListIterator (with Examples)
The Java ListIterator interface is a bidirectional iterator that iterates over the elements in both forward and backward directions.
Guide to Java Iterator
Java Iterator interface is used to iterate over the elements of a Collection (List, Set or Map). The Iterator helps in retrieving the elements from the specified collection one by one and optionally performs operations over each element. Java Iterator was first introduced in Java 1.2 as a replacement of Enumerations. …
Java Comparator Interface
Java Comparator interface used to sort a array or list of objects based on custom order. Custom ordering of elements is imposed by implementing Comparator.compare() method in the objects.
Java Comparable Interface
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Java LinkedList class
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