In-depth understanding of the technical principles and application scenarios of Guava PrimitiveTypes

In -depth understanding of the technical principles and application scenarios of Guava PrimitiveTypes introduction: GUAVA is a Java tool library for Google's open source, which aims to provide efficient, simple and reliable functions.The PrimitiveTypes module in Guava is part of it, which provides some tools and methods for processing basic types.This article will deeply explore the technical principles of the Guava PrimitiveTypes and its application scenarios, and explain its usage through the Java code example. 1. The technical principles of Guava PrimitiveTypes The technical principles of the Guava PrimitiveTypes module are mainly based on the basic types and box type conversion in Java.The basic types in Java include BOLEAN, BYTE, SHORT, INT, Long, Float, and Double, and the box type is a packaging class that corresponds to each basic type, such as Boolean, Byte, SHORT, etc. Guava PrimitiveTypes provides some tool categories and methods to simplify the conversion between basic types and box types. The most commonly used categories are PrimitiveType and Primitives. 1. PrimitiveType class: The PrimitiveType class is an enumeration class that contains each basic type in Java.By visiting the PRIMITIVETYPE instance, we can obtain basic types of class objects and conduct type judgments and conversion operations.For example, PrimitiveType.int represents int type. 2. Primitives class: The Primitives class provides a series of static methods for the conversion and judgment operations between basic types and box types.Through these methods, we can efficiently process basic types of data without manual transformation.Some common methods are as follows: -ISWRAPPPERTYPE (Class): Determine whether the given class is a packing type. -WRAP (Class): Convert the basic type to the corresponding packing type. -INWRAP (Class): Convert the box type to the corresponding basic type. -TOARAY (Iteraable): Packing the basic types in Iterable into an array type. Second, the application scenario of Guava PrimitiveTypes The Guava PrimitiveTypes module provides some practical functions and skills, which is suitable for the following application scenarios: 1. Judgment and conversion of basic types: In the development process, we often need to determine whether an object is a basic type or packing type.Using the PrimntedIVETYPE class can easily determine whether the given type is a basic type, thereby processing accordingly.Some methods of the Primitives class, such as Iswrappertype and WRAP, provide convenient type judgment and conversion functions. Example code: Class<?> clazz = Integer.class; boolean isInt = PrimitiveType.INT.equals(Primitives.unwrap(clazz)); Integer wrappedInt = Primitives.wrap(int.class); int unwrappedInt = Primitives.unwrap(wrappedInt.getClass()); 2. The operation of the basic type array: The toarray method of Guava PrimitiveTypes provides the function of converting basic types into the corresponding box type array.This is very useful in the scenario of the basic type of operation.For example, we can directly convert a basic type of ITERABLE into a array without manually traversing and converting every element. Example code: List<Integer> ints = Lists.newArrayList(1, 2, 3); int[] intArray = Primitives.toArray(ints); 3. Basic type of collection operation: The Guava collection library provides a wealth of collection operations, but they usually do not support basic types.Through the packaging type operation of Guava PrimitiveTypes, we can pack the basic types into the corresponding object, and then use the various methods of the Guava collection library for operation. Example code: IntList intList = IntLists.newArrayList(1, 2, 3); int sum = intList.stream().sum(); Summarize: Guava PrimitiveTypes provides some practical tool categories and methods to simplify the operation between basic types and box types.Through the PrimitiveType class and the Primitives class, we can easily judge, convert and operate basic types of data.It provides convenience in many application scenarios, such as type judgment, basic type array operations, and basic types of collection. It is hoped that this article can help readers understand the technical principles and application scenarios of Guava PrimitiveTypes, and apply them in actual development to improve the readability and efficiency of code. references: 1. Guava - Primitive Types: https://github.com/google/guava/wiki/PrimitivesExplained 2. Guava - Collections: https://github.com/google/guava/wiki/CollectionUtilitiesExplained