How to convert string result of enum with overridden toString() back to enum?

Question

Given the following java enum:

public enum AgeRange {

   A18TO23 {
        public String toString() {        
            return \"18 - 23\";
        }
    },
          


        

Answer 1

According to effective java (2nd ed) item 30, it can be (it is much faster than the loop)

public enum AgeRange {
       A18TO23("18-23"),
       A24TO29("24-29"),
       A30TO35("30-35");

       private final String value;

       AgeRange(String value){
          this.value = value;
       }

       @Override public String toString(){
           return value;
       }

       private static final Map stringToEnum =
           new HashMap();

       static {
           for (AgeRange r : values()) {
               stringToEnum.put(r.toString(), r);
           }
       }

       public static AgeRange getByValue(String value){
           return stringToEnum.get(value);
       }
}