Enumeration class - Singleton

 Singleton design pattern: 　　　　

　　　1, private constructors; 2, creating class object present; 3, provide external access methods

 

import java.util.jar.Attributes.Name;

public  class Week {
     Private String name;
     public  static  Final Week MON = new new Week ( "Monday" );
     public  static  Final Week TUE = new new Week ( "Tuesday" );
     public  static  Final Week WES = new new Week ( "Wednesday" ) ;
    
    private Week(String name){
        this.name = name;
    }

    public String getName() {
        return name;
    }
}

 

 

 

 

 

The enumeration class is to have multiple instances of Enum
        All of the enumeration classes are subclasses of Enum
        Enumeration must be placed on the first line

Enumeration methods of the class:
        ORDINAL () Returns the number
        compareTo (Enum e) comparing the number
        name () Returns the name of this enum constant, it declared in its enum declaration.
        valueOf(class<T> type , String name)
            Mon week2 = week2.valueOf (week2. class , Mon) by obtaining enumeration byte code file
        
        values()
            Week arr[] = Week.values();
        for (Week week : arr) {
            System.out.println(week);
        }

 

 

 

// class enumeration
 public  enum Week {
    MON, TUE, WED; // do not like to write so much trouble above       enumerated item must be placed on the first line

} 

 

public class demon1_enum {

    public static void main(String[] args) {
        My Week = Week.MON;
        switch (my) {
         case MON:
            System.out.println ( "Monday" );
             BREAK ;
         Case TUE:
            System.out.println ( "Tuesday" );
             BREAK ;
        }
    }

}

 

 

 

import java.util.Iterator;

public  class demon2_Enum {
     // Method enumeration class 
    public  static  void main (String [] args) {
        Week arr[] = Week.values();
        for (Week week : arr) {
            System.out.println(week);
            System.out.println(week.getClass());
            System.out.println(week.getClass().getName());
        }
    }

}