AOP programming in the Tapestry Core framework
AOP programming in the Tapestry Core framework
In software development, a common demand is to add new features or behaviors to the application without modifying the existing code.Facing -oriented programming (AOP) is a technology that allows developers to achieve this goal by injecting code into the horizontal cutting point of the existing code.The Tapestry Core framework, as an open source Java Web application framework, provides strong AOP programming support, enabling developers to easily apply the concept of AOP in the application.
In the Tapestry Core framework, the cut surface and enhanced logic are defined by using ASPECTJ annotations.The following is an example that demonstrates how to use AOP to implement the logging function in Tapestry Core.
First of all, we need to define a cut type, which uses @ASPECT annotations to identify.In the cut -off class, we can define various enhanced logic, such as@Before,@AFTER, and @Around.In this example, we use @Before annotations to perform logic logic before the target method is called.
import org.apache.tapestry5.aop.Before;
import org.apache.tapestry5.aop.InvocationContext;
import org.apache.tapestry5.ioc.MethodAdviceReceiver;
@Aspect
public class LoggingAspect {
@Before
public void logMethodInvocation(InvocationContext context, MethodAdviceReceiver receiver) {
String methodName = context.getMethod().getName();
System.out.println ("call method:" + MethodName);
}
}
Next, we need to configure the cut surface in the module class of the application.In the module class, we use @Contribute annotations to provide enhanced target methods for the cut surface.In this example, we add cut surface to a service called "Exampleservice".
import org.apache.tapestry5.ioc.Configuration;
import org.apache.tapestry5.ioc.MappedConfiguration;
import org.apache.tapestry5.ioc.annotations.Contribute;
import org.apache.tapestry5.ioc.annotations.ServiceId;
import org.apache.tapestry5.ioc.annotations.SubModule;
import org.apache.tapestry5.ioc.annotations.Startup;
@SubModule(MyAppModule.class)
@Startup
public class MyApp {
@Contribute(ServiceOverride.class)
public static void contributeServiceOverride(MappedConfiguration<Class<?>, Object> configuration) {
configuration.addInstance(ExampleService.class, ExampleServiceImpl.class);
}
@Contribute(MethodAdviceReceiver.class)
@ServiceId("exampleService")
public static void contributeMethodAdvice(Configuration<MethodAdviceWrapper> configuration) {
configuration.add(new MethodAdviceWrapper(LoggingAspect.class));
}
}
In this example, in the module class, the `ContributeMethodAdvice` method in the module class uses @ServiceID annotations to identify the enhanced target service, and pack the cutting type` Loggingaspect` in MethodAdviceWrapper.
Finally, we can use the ExampleService service in the application and observe the log out of the console output.
import org.apache.tapestry5.ioc.annotations.Inject;
import org.apache.tapestry5.ioc.annotations.Symbol;
import org.apache.tapestry5.ioc.annotations.ServiceId;
@ServiceId("exampleService")
public class ExampleServiceImpl implements ExampleService {
@Override
public void doSomething() {
System.out.println ("being performing certain operations ...");
}
}
public class MyAppPage {
@Inject
@Symbol("exampleService")
private ExampleService exampleService;
Object onActivate() {
exampleService.doSomething();
return null;
}
}
In this example, we injected ExampleService into the @Inject annotations and called the Dosomething method in the page class.Whenever the Dosomething method is called, the log logic logic defined in Loggingaspect is executed.
Through the AOP programming support provided by the Tapestry Core framework, we can easily add various functions and behaviors to the application without modifying the existing code.Regardless of the realization of log records, performance monitoring, or transaction management, AOP is a powerful tool that can improve the modularity and maintenance of the code.
Please note that the above example is tested under the Tapestry Core 5.4.0 version.You can adjust and modify accordingly according to your needs and framework versions.
