Spring Aspects framework original interpretation
Spring Aspects framework original analysis
Spring Aspects is a key module of the Spring framework, which provides support for cutting -oriented programming (AOP).This article will introduce the principle of the Spring Aspects framework, and explain the programming code and configuration related to it when necessary.
1. What is cut -oriented programming (AOP)?
Programming -oriented programming is a programming paradigm. It allows programmers to separate business logic from the main application code and apply universal horizontal section attention points (such as log records, transaction management, etc.) to the entire application.AOP has modularized these concerns so that developers can write applications in a more concise and reused way.
2. Principles of Spring Aspects framework
The core principle of the Spring Aspects framework is based on dynamic proxy and pattern matching.It uses ASPECTJ, a popular -oriented programming solution, and provides a way to simplify AOP configuration and use.
Spring divides each component in the application into the aspects and the business logic component (Beans).The cut surface is a special class, which contains the code of cross -cutting focus.The cut surface defines their attention points (cut points), and specify specific operations by notifying (advice).
Generally, the Spring framework uses a dynamic agent to generate proxy when runtime to achieve AOP.The interface -based proxy uses JDK dynamic proxy, while the class -based proxy uses CGLIB.
3. Use of Spring Aspects framework
Below is a simple example that demonstrates how to use AOP under the Spring Aspects framework:
(1) Define a cut -off class, which contains attention points code:
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
@Aspect
public class LoggingAspect {
@Before("execution(* com.example.service.*.*(..))")
public void beforeAdvice() {
System.out.println("Logging before the method execution.");
}
}
(2) Configuration surface and business logic components:
<bean id="loggingAspect" class="com.example.aspect.LoggingAspect" />
<bean id="myService" class="com.example.service.MyService" />
(3) Use business logic components in the application:
public class MyApp {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
MyService myService = context.getBean("myService", MyService.class);
myService.doSomething();
}
}
In the above examples, we define a cut type `Loggingaspect`. The method of` BeforeAdvice () `is executed before any method in any method in the` com.example.service` package, and print a log information.By configured cutting surfaces and business logic components, and using business logic components in the application, the Spring framework will dynamically create proxy classes during runtime, so that the focus code in the cut surface is applied.
Summarize:
The Spring Aspects framework realizes the face -oriented programming (AOP) through dynamic proxy and pattern matching.Developers can use the framework by defining cutting surface and focusing point code, and configuration cutting surface and business logic components.In this way, developers can better modularize and manage cross -sectional attention in the application to make the code more reuse and concise.
