Detailed explanation of the technical principles of the AOP Utilities framework in the Java library

AOP (ASPECT-Oriented Programming) is a methodology for software programming. By separating the horizontal cutting logic from the program subject, it is encapsulated into reusable modules.The AOP Utilities framework in the Java library provides a series of tools and practical programs, making the implementation of AOP simpler and efficient. The technical principles of the AOP framework mainly include the following aspects: 1. ASPECT: One of the core concepts of AOP, the cutting surface indicates the modular unit of cross -cut logic.A combination of a set can define a set of notifications and pointcut.In the AOP framework, the cut surface is defined by using specific annotations or configurations. 2. ADVICE: The notification represents the specific cross -cut logic, which defines the code executed on the pointcut.The AOP framework provides a variety of types of notifications, including BeFore Advice, After Advice, After Throwing Advice, and Around Advice, etc. 3. PointCut: The cut point is used to define one or more connection points, and determine which connection point triggers notification.The connection point can be the call of the method, the execution of the method, the modification of the field, and so on.The AOP framework defines the cut point by using an expression language or specific annotation. 4. Join Point: The connection point is a specific code point during the program execution process, which may trigger one or more notifications.The connection point is the basic unit in the AOP framework. Through the definition of the connection point, you can determine where and when to perform cross -cut logic. 5. Weaving: The process of weaving is the process of applying the cut surface to the target object and inserting the notification of the cut surface into the connection point of the target object.The AOP framework can be woven in compilation, loading or runtime.Weaving can be achieved through static proxy, dynamic proxy, bytecode operation. Below is an example code that uses the AOP Utilities framework in the Java library: import io.github.classgraph.*; import java.util.logging.Logger; @Aspect public class LoggingAspect { private static final Logger LOGGER = Logger.getLogger(LoggingAspect.class.getName()); @Before("@execution(public * com.example.MyService.*(..))") public void logMethodCall(JoinPoint joinPoint) { LOGGER.info("Executing method: " + joinPoint.getMethodName()); } @Around("@execution(public * com.example.MyService.*(..))") public Object measureExecutionTime(ProceedingJoinPoint proceedingJoinPoint) throws Throwable { long startTime = System.currentTimeMillis(); Object result = proceedingJoinPoint.proceed(); long endTime = System.currentTimeMillis(); LOGGER.info("Method execution time: " + (endTime - startTime) + "ms"); return result; } } public class MyService { public void doSomething() { // Method implementation } } public class Main { public static void main(String[] args) { AnnotationDB annotationDB = new AnnotationDB(); AnnotationDb.Scanarchives ("Path/To/My-APP.jar"); // Scan the annotation in the jar package ClassInfolist classinfolist = annotationDb.getannotationClasssSes ("@aspect"); // Get all categories with @Aspect annotations for (ClassInfo classInfo : classInfoList) { String className = classInfo.getName(); // Use the reflection mechanism to create the cut surface object Aspect aspect = (Aspect) Class.forName(className).getDeclaredConstructor().newInstance(); // Apply the cut surface to the target object AspectWeaver.weave(aspect, new MyService()); } MyService myService = new MyService(); myService.doSomething(); } } In this example code, a section of the cutting of a loggingaspect is defined, and the notification is defined using @Beface and @Around annotations.The logMethodCall method annotated by @BeFore will perform the previous output method name in all public methods in the com.example.myservice class; @Arounded MEASUREEEXECUTINTIME method Calculate the calculation method in front of all public methods in the com.example.myService class to calculate the calculation method. Executiontime. In the main method of the Main class, first scan the annotations in the specified jar package through the AnnotationDB in the AOP Utilities framework, and obtain all the @ASPECT annotations.Then, the cutting object is created by reflecting, and the use of ASPECTWEAVER to apply the cut surface to the target object MyService.Finally, call MyService's Dosomething method to trigger the notification of the cut surface. Through the AOP Utilities framework, we can easily implement the various functions of AOP, modify the horizontal logic logic and apply it to different target objects.This can improve the reuse of the code, reduce coupling, and make the program easier to maintain and expand.