Java: generic enum in method parameter -

correspondig following question:

java: enum parameter in method

i know, how can format code require enums generically.

foo.java

public enum foo {      a(1), b(2); } 

bar.java

public class bar {     public bar(generic enum); } 

later on i'll have more enum classes "foo", can still create bar containing kind of enum class. have "jdk1.6.0_20" way...

see methods in enumset reference, e.g.

public static <e extends enum<e>> enumset<e> of(e e) 

(this method returns enumset 1 element given enum element e)

so generic bounds need are: <e extends enum<e>>

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actually, make bar generic:

public class bar<e extends enum<e>> {      private final e item;      public e getitem(){         return item;     }      public bar(final e item){         this.item = item;     } } 

you may add factory method from, with etc.

public static <e2 extends enum<e2>> bar<e2> with(e2 item){     return new bar<e2>(item); } 

that way, in client code have write generic signature once:

// e.g. simple version bar<myenum> bar = bar.with(myenum.some_instance); // instead of more verbose version: bar<myenum> bar = new bar<myenum>(myenum.some_instance); 

reference:

• java tutorial - learning java language
  • classes , objects > enum types
  • generics