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| 1. 13. 4. 标记注释 |
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- Marker Annotations are used to mark a declaration.
- A marker annotation is a special kind of annotation.
- A marker annotation contains no members.
- Using isAnnotationPresent( ) to determine if the marker is present.
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import java.lang.annotation.Annotation;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.reflect.Method;
@Retention(RetentionPolicy.RUNTIME)
@interface MyAnnotation {
}
@MyAnnotation
public class MainClass {
// Annotate a method.
@MyAnnotation()
public static void myMethod() {
}
public static void main(String[] arg) {
try {
MainClass ob = new MainClass();
Method m = ob.getClass( ).getMethod("myMethod");
Annotation[] annos = m.getAnnotations();
System.out.println("All annotations for myMeth:");
for(Annotation a : annos)
System.out.println(a);
} catch (Exception exc) {
}
}
}
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All annotations for myMeth:
@MyAnnotation() |
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