JDK usual three notes

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• These three notes are to provide information to the compiler

 

• @Override

　　　　　1. Role:

　　　　　　　　@Target (value = the METHOD)
　　　　　　　　@Retention (the SOURCE = value)
　　　　　　　　public @interface Override represents a declaration is intended to override a superclass method as another method declaration. If you use this method to annotate annotation type but does not override the superclass method, the compiler generates an error message.

　　　　　2. Parent Class:

public class A {
　　public void st0() {
　　}
}

 　　　　       3. subclasses:

public  class B the extends A {
　　// here does not override the parent class, because the 0 as o, but the compiler does not know what you have to do, so we have to tell the compiler, 
　　the compiler will really help me to check if covered 
　　@override 
　　public  void STO () { 
　　} 
}

 

 　　　　　 4. Effects:

 

 　　　

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• @Deprecated

　　　　　1. Role:

　　　　　　　      　Retention of Documented @ @ (value = RUNTIME) public @interface of Deprecated in
　　　　　　　　　　 with @Deprecated program elements comments, do not encourage programmers to use such elements, typically because
　　　　　　　　　　it is dangerous or there is a better choice. In using the program elements are not in favor or not in favor of the code
　　　　　　　　　　is executed to rewrite the compiler will issue a warning.

　　　　    2. Class:

public  class A {
　　// wood not obsolete write 
　　public  void test1 () { 
　　} 
　　@Deprecated 
　　public  void test2 () { 
　　} 
}

 

　　　　3. Use:

　　　　

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•  @SuppressWarnings

　　　　　　　　　　　　Role: indication should be removed to display the specified compiler in the annotated element (and in all program elements contained in the annotated element) warning

　　　　1. Use : For example, we dated, we do not want to see the warning, with the notes to complete:

　　　　　　

 

 

 

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