Che Core in the Java Class Library :: Commons :: Annotions Framework Technology s libraries)
Chens in the Java Class Library :: Commons :: Annotations framework technical explanation
Background Information:
In the Java class library, che. :: Commons :: Annotations is a powerful framework to provide developers with a solution for declaration programming.It can configure and define different metadata by using annotations in the code.This article will introduce the technical principles of cheering :: Commons :: Annotations framework, as well as some example code to illustrate its usage.
Technical principle:
Chens :: Commons :: Annotations framework is implemented based on the Java annotation mechanism.Note is a metadata mode that allows developers to add markers to the code to provide additional information about program elements (such as classes, methods, fields, etc.).Che Core :: Commons :: Annotations framework has extended the Java annotation function and defines a set of their own types of annotations so that developers can configure and define metadata more flexibly.
This framework provides multiple built -in annotations, and each type of annotation has specific uses and semantics.Here are some commonly used instructions:
1. @annotationType: Used to define custom annotation types.By adding this annotation, developers can create their own annotations and set different attributes and default values.
Example code:
@AnnotationType
public @interface MyCustomAnnotation {
String value() default "";
int count();
}
2. @annotationTarget: The target element type used to specify the annotation can be applied.Developers can use this annotation to limit the use position of the annotation, such as category, methods, or fields.
Example code:
@AnnotationTarget(ElementType.METHOD)
public @interface MyMethodAnnotation {
String value() default "";
}
3. @annotationRetention: The retention strategy for specifying the annotation.According to the retention strategy, the annotation can be retained during compilation, runtime or when loading.
Example code:
@AnnotationRetention(RetentionPolicy.RUNTIME)
public @interface MyRuntimeAnnotation {
String value() default "";
}
In addition to the above examples, Chens also provides some common annotations for processing method parameters, abnormalities, thread security and other specific scenarios for processing method parameters, abnormalities, thread security.
in conclusion:
Chens :: Commons :: Annotations framework provides a powerful metadata solution that allows developers to define and configure different elements by adding annotations to the code.The framework is based on the Java annotation mechanism, extending the function of the annotation, and provides a rich type of built -in annotations.Developers can create custom annotations according to their own needs and use them for various scenarios to improve the readability and flexibility of code.
Please note that the above example code is only used to explain the purpose. In actual use, appropriate adjustment needs to be made according to specific needs.
