how to declare the possible values of an attribute in java

Question

My class must have an attribute of type string which can have just four values :

value1, value2, value3, or value4 ; 

How it can be done in java ?

Answer 1

Use enumerated types, for example

public enum MyStringType {
  value1{
      public String toString() {
          return "this is value1";
      }
  },

  value2{
      public String toString() {
          return "this is value2";
      }
  }
 /* etc etc */
}

Answer 2

It can be done a few different ways. This is the most direct (and probably ugly) way to do it, because you only have four eventualities.

 private String someString;

  public void setSomeString(String inString){
     if(inString.equals("valueOne") || 
        inString.equals("valueTwo") || 
        inString.equals("valueThree")||
        inString.equals("valueFour"){

        someString = inString;

 }else{

     //handle this here

   }