Learn from the technical principles of Google Collections framework in the Java collection library

Learn from the technical principles of Google Collections framework in the Java collection library The Java collection library is one of the commonly used tools in Java programming language, which is used to store and operate data.Google Collections is an open source Java set framework developed by Google. It extends the function of the Java set library, provides more data structures and algorithms, as well as more efficient performance and flexibility. The technical principles of Google Collection ’s framework mainly revolves around three key concepts: uncharacteria, new data structures and algorithms, and performance optimization. 1. Unchanged collection Google Collection's framework introduces the concept of unchanged collection, which refers to a collection that cannot be changed once it is created.There is the following advantages of non -changing collection: -Shrifuged security: Because the uncharacteristic set cannot be changed, it can be used in a multi -threaded environment without additional thread synchronization operation. -Dathery optimization: The internal data structure of the uncharacteristic set can be optimized to make the occupied memory less. -Simplify code: Unchanged collection can easily pass and share in the code, without having to worry about the problem of data modification. Here are a sample code created and using uncharacteristic collection: import com.google.common.collect.ImmutableList; public class ImmutableCollectionExample { public static void main(String[] args) { ImmutableList<String> immutableList = ImmutableList.of("apple", "banana", "orange"); System.out.println(immutableList); // The uncharacteristic set cannot be added and deleted, and the following code will throw out UnsupportedOperationException immutableList.add("pear"); immutableList.remove(0); immutableList.set(1, "grape"); } } 2. New data structure and algorithm The Google Collections framework also introduces some new data structures and algorithms to solve some limitations and performance problems in the Java set library.Some of these important data structures and algorithms are: -Multimap: Allows one key to map to multiple values data structures. -BIMAP: Provides a two -way mapping relationship between key and values. -TABLE: Similar to the data structure of the two -dimensional table, you can use two key index data. -Predicate and Function: For the elements in the filtering and conversion set. -F more efficient set operation: such as Union, Incesection, and Difference. The following is a Multimap sample code that uses Google Collection's framework: import com.google.common.collect.ArrayListMultimap; import com.google.common.collect.Multimap; public class MultimapExample { public static void main(String[] args) { Multimap<String, Integer> multimap = ArrayListMultimap.create(); multimap.put("fruit", 1); multimap.put("fruit", 2); multimap.put("fruit", 3); System.out.println (Multimap.get ("FRUIT"); // Output [1, 2, 3] } } 3. Performance optimization Google Collections has improved the performance of the set library through some performance optimization measures.Some of these optimizations include: -Capye memory occupation: Google Collections framework uses more efficient data structures and algorithms to reduce memory usage. -Carn the cost of iterators: The iterators in the Google Collections framework are faster and efficient. -The automatic loading and box removal: Frequent automatic boxing and boxing operations are avoided during the design of the framework, which improves performance. The performance optimization of Google Collection's framework makes it more efficient when processing large -scale data sets, suitable for applications that require fast and reliable collection operations. In summary, in -depth learning of the technical principles of Google Collections framework in the Java collection library can allow developers to better understand and use this powerful tool, optimize the performance of the code, and provide richer functions.Whether it is uncharacteristic collection, new data structure and algorithm, or the benefits of performance optimization, Google Collections framework can become one of the important tools in Java development.