Springframework Aop: The cut -off programming practice in the Java class library
Spring Framework Aop: cut -off programming practice in the Java class library
Introduction:
Cutting surface programming is a design pattern in object -oriented programming. It can dynamically separate the cross -section attention point (also known as the horizontal section attention point) from the normal business logic when the program is running.In Java development, Spring Framework provides a powerful AOP (Aspect-Oriented Programming) framework to achieve cutting programming.This article will introduce how to use the Spring Framework Aop to practice cutting programming and provide examples of Java code.
What is cutting programming?
Cutting programming is a programming paradigm that is used to solve the problem of recurrence of system -level attention points across multiple classes and objects and the separation of cross -section attention points and business logic.By using the cut surface, the code related to the horizontal section can be modularized, and it can be dynamically woven into the program when needed.The cut surface is usually used to process system -level attention points, such as log records, performance monitoring, transaction management, etc.
Spring Framework AOP Overview:
Spring Framework Aop is an agent -based cut -off programming framework.It uses proxy objects to intercept the method call, and inserts additional behaviors before, after execution, or throwing abnormality.Spring Framework AOP follows the core principles of cutting -oriented programming -is to separate the duties of cutting as much as possible from the business logic and apply it to the target object through a statement configuration.
The purpose of Spring Framework Aop:
1. Logging: Through the calling of the business method, the log records can be achieved, including the method of parameters, return value, and execution time of the method.
2. Performance monitoring: You can record the timestamp before and after the method call, and the execution time of the calculation method is used for performance monitoring and optimization.
3. Affairs management: The call through intercepting database operations and other methods, open and submit transactions before and after the implementation of the method to achieve declaration -style transaction management.
4. Abnormal treatment: The exception can be captured by the method of calling the method, and processing, recording or throwing new abnormalities according to the needs.
Core concept of Spring Framework Aop:
1. PointCut: The method set of the method of the target object to be knitted.
2. Notification (Advice): The logic defined at the cut point, including the code executed before, after the target method executes, or throws out abnormalities.
3. ASPECT: combine the cut point and notification to form a cut surface.The cut surface defines which target objects to be woven and when (that is, which cut point) to weave in.
Example code:
Below is a simple example code that explains how to use the Spring Framework Aop to implement the log record function.
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;
@Aspect
@Component
public class LoggingAspect {
@Before("execution(* com.example.service.*.*(..))")
public void logBefore(JoinPoint joinPoint) {
System.out.println("Before method execution: " + joinPoint.getSignature().getName());
}
@After("execution(* com.example.service.*.*(..))")
public void logAfter(JoinPoint joinPoint) {
System.out.println("After method execution: " + joinPoint.getSignature().getName());
}
}
In the above example, we define a cut surface called `Loggingaspect`, and use the annotations of`@before` and@asfter` to mark the method `logBeface` and` logaFTER`, which means that they will be before and and and.After the execution.In the intercepting method, custom logic can be performed, such as output log information.
in conclusion:
Spring Framework Aop provides a powerful cut -off programming tool for Java developers.With the help of Spring Framework AOP, developers can easily use the cut surface in the application to improve the modularity and maintenance of the code.Through reasonable application of the cut surface, system -level attention points can be separated from business logic to achieve more efficient and easier maintenance code writing.
