Use the 'Contracts for Java' framework to implement reliable contract verification in the Java class library

Use the 'Contracts for Java' framework to implement reliable contract verification in the Java class library Overview: 'Contracts for Java' is an open source framework that can help Java developers to achieve contract verification.It provides a simple and flexible way to write and verify the front conditions, rear conditions, and invariance.This article will introduce how to use the 'Contracts for Java' framework to implement reliable contract verification in the Java library and provide some Java code examples to help understand. Why use contract verification: In software development, contract verification is an important technology to ensure the correctness and reliability of the program.By defining and verifying the contract, we can specify the specific conditions of the method before and after executing to ensure the accuracy of the input, prevent potential errors or abnormalities, and ensure the results of the method to meet the expectations.Contract verification can help us improve the quality of code, reduce debugging time, and increase the maintenance of code. Use 'Contracts for Java' framework: The following will introduce how to use the 'Contracts for Java' framework to implement contract verification in the Java library. Step 1: Download and integrated framework First of all, you need to download the jar file of the framework from the official website (https://contract4j.github.io/).Then, the downloaded jar file was imported into the project's class path to use it in the code. Step 2: Write contract verification code After preparing the framework, we can start writing code to define and verify the contract.'Contracts for Java' provides many annotations for contract verification in the form of annotations, including@Requires,@Ensures, and @Invariant.Here are some commonly used annotations and its purpose: -@Requires: The front conditions for defining the method, that is, the conditions that must be met before the method execute. -@ENSURES: The rear conditions for defining the method, that is, the conditions that must be met after the method execute. -@Invariant: Used to define the unity of the object, that is, the conditions that the object must meet at any time. The following is an example code that demonstrates how to use the above annotation to verify the contract: public class MathUtils { // The parameters that need to be passed cannot be zero @Requires("number != 0") public static int divide(int dividend, int divisor) { return dividend / divisor; } // The result of returned must be greater than equal to 0 @Ensures("$result >= 0") public static int absolute(int number) { return Math.abs(number); } // The object of the object: the size must be greater than 0 @Invariant("size > 0") public class MyList<T> { private int size; // ... } } Step 3: Enable contract verification To enable contract verification, we need to use the tool provided by 'Contracts for Java' to check the contract during runtime.You can set runtime parameters in the configuration file of the project, such as command line options, system attributes or configuration files to specify which contracts should be enabled or disabled.The detailed configuration description and sample code can be found in the official documentation of 'Contracts for Java'. Summarize: By using the 'Contracts for Java' framework, we can easily implement contract verification in the Java library.It provides us with a simple and flexible way to write and verify the front conditions, rear conditions, and invariability of the method.Contract verification helps improve the quality of code, reduce debugging time, and increase the maintenance of code.I hope this article will help you understand how reliable contract verification in the Java library will be helpful.