Common uses of Java enumeration (enum)

JDK1.5 introduces a new type--enumeration. In Java, although it is a "small" function, but to my development has brought "big" convenience.

Usage One: constant.

Before JDK1.5, we defined constants: public static fianl ..... Now, with enumerations, you can group related constants into an enumeration type, and enumerations provide more methods than constants.

 Public enum Color {     RED, GREEN, BLANK, YELLOW}

Simple to use
publicclassB {

     public static void main(String[] args) {          System. out .println( isRed( Color.BLANK ) ) ;   //结果： false          System. out .println( isRed( Color.RED ) ) ;     //结果： true      }      static boolean isRed( Color color ){          if ( Color.RED. equals ( color )) {              return true ;          }          return false ;      } 　　}Or the use of switch

Signal color = signal.red;

　　Public Void Change () {

switch (color) {

　　　　　　Case RED:

color = Signal.green;

Break ;

　　　　　　Case YELLOW:

color = signal.red;

Break

　　　　　　Case GREEN:

color = Signal.yellow;

Break ;

}

}

Usage Two: Methods for overriding enumerations

An example of the ToString () method overlay is given below.

enumcolor{RED ("Red", 1), Green ("green", 2), BLANK ("White", 3), Yello ("Yellow", 4); //member Variables    PrivateString name; Private intindex; //Construction Method    PrivateColor (String name,intindex) {           This. Name =name;  This. index =index; }      //override Method@Override PublicString toString () {return  This. index+ "_" + This. Name; }  }
Usage
Color.RED.toString (); Print 1_ Red

Similarly, it can also be a parameter 　 
Enum Execstatus {

WAIT (' 0 '), PROGRESS (' 1 '), SUCCESS (' 2 '), ERROR (' 3 ');
Private char State;

Private Execstatus (char state) {
This.state = State;
}

Public Char GetValue () {
return state;
}

@Override
Public String toString () {
return string.valueof (state);
}
}

Usage
ExecStatus.WAIT.getValue ()//Print 0

Common uses of Java enumeration (enum)