Guide to annotation with FLUENT Reflection Parent framework
Guide to annotation with FLUENT Reflection Parent framework
Overview:
Note processing is a powerful function in the Java language, and some tasks can be performed through the annotation.FLUENT Reflection Parent is a framework for simplifying the annotation processing. It provides a way that is easier to understand and operate to use Java's reflection mechanism processing.
step:
1. Add dependencies:
In your project, you first need to add the deletion of the FLUENT Reflection Parent framework.You can add it through Maven or Gradle.
Maven configuration example:
<dependencies>
<dependency>
<groupId>org.fluentcodes</groupId>
<artifactId>fluent-reflection-parent</artifactId>
<version>1.0.0</version>
</dependency>
</dependencies>
Gradle configuration example:
gradle
dependencies {
implementation 'org.fluentcodes:fluent-reflection-parent:1.0.0'
}
2. Create injection class:
Next, you need to define one or more custom annotations.The annotation class is defined by keywords of `@interface`.For example, we create an annotation class called `@customannotation`.
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface CustomAnnotation {
String value() default "";
}
This annotation class has a attribute called `value`, and you can add more attributes as needed.
3. Create the annotated class:
In your project, create a category of annotation and use the annotations you just defined.For example, we create a class called `myclass` and use the`@customnotation` annotation that I just defined.
public class MyClass {
@CustomAnnotation("Hello, World!")
public void myMethod() {
// Execute custom logic
}
}
4. Create an annotation processor:
Create a class to handle the category with annotations.You can implement the `Elementhandler` interface, and rewrite the` handle` method to define your own annotation processing logic.
import org.fluentcodes.reflection.fluent.ReflectInvoker;
import org.fluentcodes.reflection.fluent.ReflectionsClassProxy;
import org.fluentcodes.reflection.fluent.ReflectionType;
import org.fluentcodes.reflection.fluent.ReflectionsProxyData;
import java.lang.annotation.Annotation;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
public class CustomAnnotationHandler implements ElementHandler {
@Override
public void handle(Class<?> clazz, String methodName, Annotation annotation) {
if (annotation instanceof CustomAnnotation) {
CustomAnnotation customAnnotation = (CustomAnnotation) annotation;
String value = customAnnotation.value();
// Execute the corresponding logic according to the value of the annotation
System.out.println(value);
}
}
}
In the `Handle` method, you can get the category, method name, and annotation instance of the annotation, so as to execute the corresponding processing logic according to the value of the annotation.
5. Execute the annotation:
After completing the writing of the annotation processor, you can execute the logic of the annotation processing.Using Fluent Reflection Parent framework, you can perform annotations through the following ways.
public class Main {
public static void main(String[] args) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
MyClass myClass = new MyClass();
ReflectionsProxyData reflections = ReflectionsClassProxy
.builder()
.object(myClass)
.type(ReflectionType.CLASS)
.build();
ReflectInvoker reflectInvoker = new ReflectInvoker(reflections);
reflectInvoker.invokeElement(new CustomAnnotationHandler());
}
}
In this example, we first created an instance of the `MyClass`, and then used the` ReflectionSclassProxy` to obtain the reflected information of the class.Next, use the `Reflectinvoker` to perform the annotation processing and pass it into our custom annotation processor.The annotation processor is called and the corresponding logic is executed according to the annotation value.
Summarize:
By using Fluent Reflection Parent framework, we can simplify the process of annotation processing and perform certain tasks from dynamic execution.You only need to define your own annotation class and annotation processor, and then use the tool class provided by the framework to perform the annotation processing logic.In this way, you can use Java's reflection mechanism to handle annotations more conveniently.
