GUAVA (GOOGLE Common Libraares) Original Type Java Class Library Introduction Guide

GUAVA (GOOGLE Common Libraares) Original Type Java Class Library Introduction Guide introduce Guava is a powerful Java class library developed by Google, which aims to provide Java developers more convenient and efficient coding experience.Among them, the original type library of Guava provides a series of convenient functions and tools for the basic types of Java (such as int, long, etc.). In this guide, we will learn how to use the original type library of Guava, understand the functions and characteristics it provided, and demonstrate through the Java code example. 1. Range (range) class Range is a very useful original type in Guava, which is used to handle the exponential and operation of the scope.It can indicate a semi -open interval (the open range, contains the starting value without the end value) or the closed interval (closed interval, including the starting value and end value). The following are several common methods for creating the Range object: Range<Integer> openRange = Range.open(1, 5); // (1, 5) Range<Integer> closedRange = Range.closed(1, 5); // [1, 5] Range<Integer> openClosedRange = Range.openClosed(1, 5); // (1, 5] Range<Integer> closedOpenRange = Range.closedOpen(1, 5); // [1, 5) The Range class also provides many convenient methods, such as whether the scope of judgment contains a certain value, upper and lower bounds from the scope of acquisition. 2. Preconditions (front conditions) class Preconditions is a practical class provided by Guava to simplify the conditional judgment in programming.Through the Preconditions class, we can write the code for pre -conditioning verification more clearly and simply. The following are several typical examples of using the Preconditions class: -Check whether the parameter is null: public void process(String input) { Preconditions.checkNotNull(input, "input cannot be null"); // ... } -Check whether the parameter meets a certain condition: public void divide(int dividend, int divisor) { Preconditions.checkArgument(divisor != 0, "divisor cannot be zero"); // ... } -Check whether the status of an object meets a certain condition: public void performOperation() { Preconditions.checkState(isInitialized, "operation cannot be performed before initialization"); // ... } 3. Primitives (basic type) class The Primitives class provides a set of tools to operate the basic data types of Java.It can help us perform the conversion, comparison, and distribution of basic types and packaging types. Here are some common methods provided by the Primitives class: -Promatize whether the two basic types are equal: int[] array1 = {1, 2, 3}; int[] array2 = {1, 2, 3}; boolean isEqual = Primitives.equals(array1, array2); // true -Colon the type of packaging corresponding to the basic type: Class<Integer> wrapperType = Primitives.wrap(int.class); -Cify whether a class is a basic type or its packaging type: boolean isPrimitive = Primitives.isWrapperType(Integer.class); // true Summarize GUAVA's original type Java class library provides strong and convenient tools for Java developers, which can handle basic types of data and operations more efficiently.In this article, we briefly introduced the GUAVA Range class, Preconditions class, and Primitives classes, and demonstrated it through sample code.By learning the original type library of Guava, you can focus more on the development of core business logic and improve code writing efficiency and readability.