Interpret the technical principles and applications of Google Collection frame in the Java class library

In the Java class library, Google Collections is a powerful framework that is used to process the setting data structure and provide richer operation methods.Below will interpret the technical principles and applications of Google Collections framework in the Java library. Technical principle: Google Collection ’s framework is based on the Java standard library's set framework, providing developers with many enhanced functions.It uses many efficient data structures and algorithms to optimize the performance of the collection operation and introduce some new concepts and design patterns. 1. Immutable Collections: Google Collections introduces the concept of uncharacteristic set, that is, a collection that cannot be changed once it is created.These collections are safe in the concurrent environment and improve the performance of the program.The unsatisfactory collection can be created by copying the existing collection, and any modification of the original collection will not affect the new collection. 2. New data structures and algorithms: Google Collections introduces some new data structures and algorithms, such as Multimap and Multiset, which is used to handle the operation of key values and multiple sets.It also provides a more flexible set of sets, such as Linkedhashset and TreeMultise to sort the elements or accesses the insertion order.These new collection types can meet different needs of developers. 3. Functional programming: Google Collections supports functional programming style. By introducing functional interfaces and anonymous categories, it provides a more concise collection operation method.For example, you can use the Function interface to define the conversion function of the set element and use the Predicate interface to filter the elements in the set. application: The Google CollectionS framework is widely used in practical applications, as shown below: 1. More flexible collection operation: By using the rich methods provided by Google Collections, you can easily filter, conversion, sorting and other operations.For example, you can use the Filter method to filter out elements that meet certain conditions, and use the transform method to convert the elements in the set. 2. More efficient data access: Google Collections framework provides efficient data structure and algorithm, which can make the collection of access and operation more efficient.For example, using linkedhashmap can access the set in the order of the element, and use Treemultiset to access the collection in the order of the element. 3. Parallel security: It is a thread security in the complicated environment, which means that multiple threads can access and use these sets at the same time without additional synchronous measures.This is very helpful for improving the performance of programs and simplifying code. Below are some Java code examples of Google Collection's framework: 1. Create an uncharacteristic collection: ImmutableList<String> immutableList = ImmutableList.of("apple", "banana", "orange"); ImmutableSet<Integer> immutableSet = ImmutableSet.copyOf(Arrays.asList(1, 2, 3)); 2. Collection operation: List<String> fruits = Arrays.asList("apple", "banana", "orange"); List<String> filteredFruits = Collections2.filter(fruits, input -> input.startsWith("a")); Collection<String> transformedFruits = Collections2.transform(fruits, input -> "I love " + input); 3. Efficient data access: LinkedHashMap<String, Integer> linkedHashMap = new LinkedHashMap<>(); linkedHashMap.put("apple", 1); linkedHashMap.put("banana", 2); linkedHashMap.put("orange", 3); for (Map.Entry<String, Integer> entry : linkedHashMap.entrySet()) { System.out.println(entry.getKey() + ": " + entry.getValue()); } Summarize: The Google Collections framework provides developers with more powerful and flexible collection capabilities for developers by introducing uncharacteristic collection, new data structures and algorithms, and supporting functional programming styles.It is important in improving program performance, simplifying code writing, and increasing concurrent security.