Smart weapon of extended Java library function: detailed explanation "Sticky Metadata Reflective 3" framework
Smart weapon of extended Java library function: detailed explanation "Sticky Metadata Reflective 3" framework
introduction:
In Java programming, the use of class libraries is a common means to improve development efficiency.However, under certain special needs, we may need to expand the function of the library to meet our business logic.Today we will introduce a powerful tool, "Sticky Metadata Reflective 3" framework, which can help us easily expand the function of the Java class library.
1. Understand "Sticky Metadata Reflective 3" framework
"Sticky Metadata Reflective 3" is an open source Java framework that realizes a dynamic expansion of the Java -class library function by using the reflection mechanism and metadata.With this framework, we can enhance the function of the existing library without modifying the source code.
2. Core principle of framework
The core principle of the "Sticky Metadata Reflective 3" framework is to use the Java's reflection mechanism to dynamically call and modify the behavior of the class by reading and analytical metadata information.
3. Use examples
In order to better understand the use of the "Sticky Metadata Reflective 3" framework, we will give an example of use: Assuming we want to expand a existing library to enable it can be printed before calling the class library method, we can print the method to print the method.Execution time and parameters.
First of all, we need to define an annotation that is used to mark the way to enhance.The example code is as follows:
import java.lang.annotation.*;
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface LogExecutionTime {
}
This annotation is added to the specific method in the class library.The example code is as follows:
public class LibraryClass {
@LogExecutionTime
public void libraryMethod() {
// The implementation of the class library method
}
}
Next, we use the "Sticky Metadata Reflective 3" framework to achieve functional enhancement.We need to create a proxy class to perform relevant logic before and after the method call.The example code is as follows:
import com.stickymetadata.reflective3.*;
import java.lang.reflect.*;
public class EnhancedLibraryClass extends LibraryClass {
@Override
public void libraryMethod() {
try {
Method originalMethod = LibraryClass.class.getMethod("libraryMethod");
MethodProxy methodProxy = MethodProxyFactory.create(originalMethod);
// Print the method name before the method call
System.out.println(originalMethod.getName() + " - Method execution started");
// Call the original method
methodProxy.invokeSuper(this, null);
// Print the method name after the method calls
System.out.println(originalMethod.getName() + " - Method execution completed");
} catch (Throwable t) {
// Treatment abnormalities
}
}
}
Finally, we can use the enhanced class to replace the original class library, thereby achieving the functional enhancement of the method.The example code is as follows:
public class Main {
public static void main(String[] args) {
LibraryClass library = new EnhancedLibraryClass();
library.libraryMethod();
}
}
By running the above code, we will see the execution time and parameters of the class library method at the console.
4. Summary
In this article, we introduced the "Sticky Metadata Reflective 3" framework in detail. It is a powerful tool that helps us expand the function of the Java class library.By using the reflection mechanism and metadata, we can dynamically call and modify the behavior of the class to enhance the function of existing libraries.I hope this article can help you understand and use this framework.
