How to use Javax Internet

Javax Interceptor API is a standardized AOP (cut-off programming) solution for Java platform, which provides a way to separate the Cross-Cutting Concers from business logic.This article will introduce the use of the Javax Interceptor API framework and explain the relevant programming code and configuration. Overview: The Javax Interceptor API framework allows developers to intercept the method calls or classification by defining the interceptor, and perform specific processing logic before these methods call or instantiate.This processing logic is usually related to cross -cutting logic, such as log records, performance monitoring, abnormal processing, etc. Steps for usage: 1. Define a interceptor class: First of all, we need to create a Java class to implement the interceptor interface (javax.interceptor.invocationContext).The interceptor class should contain a method of@javax.interceptor.aroundinVoke annotation modification, which will be executed before and after the goal method calls. @javax.interceptor.Interceptor public class MyInterceptor { @AroundInvoke public Object intercept(InvocationContext context) throws Exception { // Execute the logic before the method call // ... try { // Call the target method Object result = context.proceed(); // Execute the logic after the method calls // ... return result; } catch (Exception e) { // Abnormal processing logic // ... throw e; } } } 2. Define a target category with an interceptor annotation: Next, we need to define a target class and use@javax.interceptor.interceptors annotation to associate the interceptor class with the target class. @javax.interceptor.Interceptors(MyInterceptor.class) public class MyService { public void doSomething() { // The implementation of the target method // ... } } 3. Configuration interceptor: To ensure that the interceptor can be managed and executed by the container, we need to declare the interceptor in the app's configuration file (such as web.xml). <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1"> <interceptors> <class>com.example.MyInterceptor</class> </interceptors> </web-app> 4. Call the target method: Finally, when calling the target class in the application, the interceptor will automatically intercept and execute related logic. public class MyApp { public static void main(String[] args) { MyService service = new MyService(); service.doSomething(); } } Summarize: The Javax Interceptor API framework provides a simple and flexible method for Java developers to achieve AOP programming.By using the interceptor class and annotations, developers can separate the general processing logic from the business logic and apply it to various methods to call or instantiated.This method can improve the maintenance and reuse of the code, and can dynamically modify the behavior of the system during runtime.