Enum in Java 5

Features of Enum in Java 5:
1. Enum is a class;
2. Enum is final and cannot be inherited, and the value cannot be overwritten;
3. You can use "=" and "equals ()" to compare enum;
Enum before Java 5:

1 Package Com. Kay. java5.test1;
2
3 Public   Final   Class Grade {
4
5 Public   Static   Final String =   " A " ;
6 Public   Static   Final String B =   " B " ;
7 Public   Static   Final String C =   " C " ;
8 Public   Static   Final String d =   " D " ;
9 Public   Static   Final String E =   " E " ;
10 }

Enum in Java 5:

1 Package Com. Kay. java5.test1;
2
3 Public   Enum Gradeenum {
4 A, B, C, D, E, F
5 }
6

Or:

1 Package Com. Kay. java5.test1;
2
3 Public   Class Enumtest {
4
5 Private   Enum Grade {a, B, c, d };
6
7 Private   Static   Enum Grade2 {f, g, h };
8 }

Print the content in Enum:

Package Com. Kay. java5.test1;

Public ClassTest {

Public   Static   Void Main (string [] ARGs ){

Gradeenum [] Ge = Gradeenum. Values (); // The values () method returns the array of all values in Enum.

For ( Int I =   0 ; I < GE. length; I ++ ){
System. Out. println (GE [I]);
}

}

}

Enum in switch:

Package Com. Kay. java5.test1;

Public ClassTest {

Private   Static   Enum E {a, B, c, d };



Public   Static   Void Main (string [] ARGs ){

Switch (E. ){
Case A:
System. Out. println ( " A " );
Break ;
Case B:
System. Out. println ( " B " );
Default :
System. Out. println ( " C or D " );
}
}
}

Enummap is a new set in Java 5 that uses enme as the key in map:

Package Com. Kay. java5.test1;

ImportJava. util. enummap;

Public   Class Test {


Public   Static   Void Main (string [] ARGs ){
// Enummap constructor <Enum, Object>
Enummap < Gradeenum, string > Emap =   New Enummap < Gradeenum, string > (Gradeenum. Class );
// Assignment
Emap. Put (gradeenum., " This is! " );
Emap. Put (gradeenum. B, " This is B! " );
Emap. Put (gradeenum. C, " This is C! " );
Emap. Put (gradeenum. D, " This is D! " );
Emap. Put (gradeenum. E, " This is e! " );
Emap. Put (gradeenum. F, " This is F! " );

// Value
System. Out. println (emap. Get (gradeenum. ));

}
}

Retrieve all values in enummap:

Gradeenum [] Ge = Gradeenum. Values ();
For ( Int I =   0 ; I < GE. length; I ++ ){
System. Out. println (emap. Get (GE [I]);
}

Enumset: Enumset es = Enumset. Allof (gradeenum. Class ); // Put all the elements in gradeenum into enumset
Enumset EE = Enumset. Of (gradeenum. A, gradeenum. B ); // Put the specified element in gradeenum into enumset

// Value
Iterator ITER = Ee. iterator ();
While (ITER. hasnext ()){
System. Out. println (ITER. Next ());
}