The scalability and flexibility of the Java library through ST Metrics

The scalability and flexibility of the Java library through ST Metrics Abstract: When developing a large Java project, it is crucial to create scalable class libraries.This article introduces how to use the ST Metrics tool to evaluate and improve the scalability and flexibility of the Java class library.Through reasonable code structure and design, developers can make their own libraries easier to expand and adapt to change. introduce As a commonly used programming language, Java provides a wealth of libraries for developers.However, as the project becomes more and more complicated, developers often need to create their own libraries to meet specific needs.In this case, creating scalable class libraries is very important, so that developers can easily add new functions or modify existing functions as needed. ST Metrics is a tool for evaluating and improving software quality. It can help developers analyze various indicators of code, such as complexity, coupling, internal aggregation, etc.This article will introduce how to use the ST Metrics tool to evaluate and improve the scalability and flexibility of the class library. 1. Design reasonable class structure A good class structure is the basis for achieving scalability and flexibility.First of all, the code should be divided into different classes and packages according to the function.Each class should have a clear responsibility, only responsible for a specific function.This can improve the internal agglomeration of the class library and make it easier to understand and maintain. For example, a library management system is considered, including books, users and borrowing records.These classes should be placed in different packages and interacting through appropriate interfaces to achieve decoupling between classes. 2. Reduce the complexity of the type When designing the class library, try to avoid creating too complicated classes.Complex categories are difficult to understand and maintain, and it is also quite difficult for extension and modification. Use ST Metrics to evaluate the complexity of the class.For example, you can use the "McCabe CyClomatic Complexity" indicator to measure the complexity of a method.The number of different execution paths in this indicator represents the larger the number, the higher the complexity.For high complexity methods, you can consider splitting it into multiple simple methods to improve the understanding and scalability of the code. The following is an example code that contains a complex method: public class ExampleClass { public void complexMethod(int x, int y) { // Complex logical operation if (x > y) { // Complex conditional branch for (int i = 0; i < x; i++) { // Cycle operation if (i % 2 == 0) { // Logic logic System.out.println(i); } } } } } You can use ST Metrics to evaluate the complexity of the method and consider how to reconstruct it to improve scalability and flexibility. 3. Improve the internal agglomeration of code High -end agglomeration is the key to achieving scalability and flexibility of the class library.Internal agglomeration refers to whether a class or method is only responsible for a specific function.A category of height will have less dependencies, making it easier to be expanded or modified. Through ST Metrics, you can evaluate the internal agglomeration of the class.For example, you can use the "Lack of Cohesion of Methods" indicator to measure the internal agglomeration of the class.This indicator represents the degree of coupling between the Chinese method. The lower the value, the higher the internal agglomeration.For classes with low internal agglutination, you can consider splitting it into multiple more internal aggregate classes. Here are a sample code that contains a class with a lower internal aggregation: public class ExampleClass { private int x; private int y; public void methodA() { System.out.println(x); } public void methodB() { System.out.println(y); } public void methodC() { System.out.println(x + y); } } ST Metrics can be used to evaluate the internal agglomeration of this class and consider how to reconstruct it to improve scalability and flexibility. in conclusion Through the ST Metrics tool, the scalability and flexibility of the Java class library can be evaluated and improved.By designing a reasonable class structure, reducing the complexity of the class, and improving the internal agglomeration of code, developers can make their own libraries easier to expand and adapt to change. Reference materials: 1. ST Metrics: [https://www.stmetrics.com/](https://www.stmetrics.com/) 2. Henney, Kevin. "Metrics languages and software quality." STC Report 7 (1989): 4-5. The above is all the contents of this article. I hope to understand how to realize the scalability and flexibility of the Java library through ST Metrics.Thank you for reading!