Custom annotation Annotation

Custom annotation myannotation. Java

/**
* Custom method description Annotation
* @ Author archie2010
* Since 2011-3-17 06:20:29
*/
@ Target (elementtype. Method)
@ Retention (retentionpolicy. runtime)
@ Brief ented
@ Inherited
Public @ interface myannotation {

Public String desc1 () Default "no description ";

Public String desc2 () Default "no description ";
}

* Meta annotation @ target, @ retention, @ incluented, @ inherited

* @ Target indicates where the annotation is used. Possible elemenettype parameters include:

* Elemenettype. constructor Declaration

* Elemenettype. Field field Declaration (including Enum instances)

* Elemenettype. local_variable local variable Declaration

* Elemenettype. Method method declaration

* Elemenettype. Package package Declaration

* Elemenettype. Parameter parameter Declaration

* Elemenettype. Type class, interface (including annotation type) or enum Declaration

* @ Retention indicates the level at which the annotation information is saved. Optional retentionpolicy parameters include:

* The retentionpolicy. Source annotation will be discarded by the compiler.

* The retentionpolicy. Class annotation is available in the class file, but is discarded by the VM.

* Retentionpolicy. runtime VM also retains annotations during runtime. Therefore, the annotation information can be read through the reflection mechanism.

* @ Brief ented include this annotation in javadoc

* @ Inherited allows subclass to inherit the annotation in the parent class

Person. Java

Public class person {

@ Myannotation (desc1 = "method description 1", desc2 = "method description 2 ")
Public void add (integer I ){
System. Out. println ("---------");
}
}

Test class

Testannotation. Java

/**
* Annotation Test
* @ Author archie2010
* Since 2011-3-17 03:34:56
*/
Public class testannotation {

@ Suppresswarnings ("unchecked ")
Public static void main (string [] ARGs) throws throwable {
// Myannotation = new person (). getclass (). getmethod ("add"). getannotation (myannotation. Class );

// The clazz parameter is not required when obtaining the method with parameters...
Myannotation = new person (). getclass (). getmethod ("add", integer. class ).
Getannotation (myannotation. Class );

System. Out. println (myannotation. desc1 ());
System. Out. println (myannotation. desc2 ());

System. Out. println (integer. Class. tostring ());
System. Out. println (long. Class. tostring ());
If (integer. Class. tostring (). Equals ("class java. Lang. Integer ")){
System. Out. println ("------ equal ");
}
}
}