Analysis of the principle of the Pure4J Core framework in the Java class library

Pure4J Core is a framework for Java libraries. By providing some additional functions and constraints, it helps developers to write more pure, robust and maintainable code.The main principle of the Pure4J Core framework is to achieve verification and limitations of methods in the Java class to ensure the purity and reliability of the code. The core idea of the Pure4j Core framework is to verify and restraint the code during compilation to avoid potential errors and hidden dangers, and provide better code quality and reliability at runtime.The principle of the Pure4J Core framework will be analyzed in detail below. 1. Note and annotation processors: Pure4j Core uses custom annotations to mark and limit methods.Developers can specify the expected behavior of the method by using the annotations provided by the Pure4J Core framework, such as pure functions, no side effects, and immutable.These annotations can help developers ensure the purity and reliability of the code. 2. The working principle of the annotation processor: The Pure4j Core framework uses the annotation processor to analyze and process the method of the marking.The annotation processor can perform a static analysis of the code during compilation, find the Pure4J Core annotation on the search method, and generate the corresponding code.For example, when a method is marked as a pure function, the annotation processor can generate additional code to ensure that the method does not produce any side effects and mark it as non -variable. 3. Method verification and restrictions: The Pure4j Core framework is verified and restricted by the parameter and return value of the method through the annotation processor.For example, if a method is marked as a pure function, its parameters cannot be variable, and the return value can only depend on the value of its input parameters.By verifying and restrictions on methods, Pure4J Core can help developers capture potential errors and problems, and provide better code quality and reliability. Below is a sample code using the Pure4J Core framework: import pure4j.annotations.sideeffectfree.SideEffectFree; import pure4j.annotations.pure.Pure; public class MathUtils { @Pure public static int add(int a, int b) { return a + b; } @Pure public static int multiply(int a, int b) { return a * b; } @SideEffectFree public static void printResult(int result) { System.out.println("Result: " + result); } } In the above example code, the method of `add ()` and `multiply ()` is marked as a pure function (Pure). Their return value only depends on the value of the input parameters without side effects.`PrintResult ()` The method is marked as no side effect (SIDEEFFECTFREE), it does not change any state, it just prints the result. By using the annotations and annotations provided by the Pure4j Core framework, developers can check the code during compilation and limit the code to ensure the purity and reliability of the code.This helps to write a more robust, maintenance and easy -to -understand Java code.