Java: Converting String to Enum

Sometimes is necessary to convert a String value to an Enum, perhaps because we have the value as a String in the database, but we want to manipulate it as an Enumerator in the Java code.

The follow code shows hot to obtain the Enum value from a String. Basically, a static method is added to the Enum to return the specif Enum value. This is accomplished by iterating all the Enum values and making a comparison with the String value passed as a parameter. If the String does not match with any of the values, then an illegal argument exception is thrown.

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public enum Volcano {    IRAZU("Irazu"), POAS("Poas"), ARENAL("Arenal"), RINCON_DE_LA_VIEJA("Rincon de la vieja");    private String name;    private Volcano(String name) {   this.name = name;  }    public static Volcano fromString(String name) {   if (name == null) {    throw new IllegalArgumentException();   }   for (Volcano volcano : values()) {    if (name.equalsIgnoreCase(volcano.getName())) {     return volcano;    }   }   // Passed string value does not correspond to a valid enum value.   throw new IllegalArgumentException();  }    public String getName() {   return this.name;  }    public static void main(String[] args) {   Volcano volcano1 = Volcano.fromString("Poas");   System.out.println(volcano1);     Volcano volcano2 = Volcano.fromString("rincon de la vieja");   System.out.println(volcano2);     Volcano volcano3 = Volcano.fromString("Fuji");  } }

Output:

POAS
RINCON_DE_LA_VIEJA
java.lang.IllegalArgumentException
 at com.bodybuilding.common.enums.Volcano.fromString(Volcano.java:22)
 at com.bodybuilding.common.enums.Volcano.main(Volcano.java:36)