What is the reason for java lang IllegalArgumentException No enum const class even though iterating through values works just fine

Question

This question is basically an extension of my previous question   I asked the previous question to be sure that the Enum constants are populated when the class loads   Here s is my class again with the addition of a simple method getByName    public enum PropName      CONTENTS  contents      USE QUOTES  useQuotes      ONKEYDOWN  onkeydown      BROWSER ENTIRE TABLE  browseEntireTable      COLUMN HEADINGS  columnHeadings      PAGE SIZE  pageSize      POPUP TITLE  popupTitle      FILTER COL  filterCol      SQL SELECT  sqlSelect           private String name     private PropName String name        this name   name         public String getName         return name         public static PropName getByName String name       return   PropName valueOf name           A call to the method getByName  columnHeadings   is throwing java lang IllegalArgumentException  No enum const class labware web component limsgrid PropName columnHeadings but if I replace this method with the following code it just works     public static PropName getByName String name       for PropName prop   values           if prop getName   equals name            return prop                     throw new IllegalArgumentException name     is not a valid PropName          Any ideas as to what I am doing wrong here

User · Accepted Answer

Enum valueOf   only checks the constant name  so you need to pass it  COLUMN HEADINGS  instead of  columnHeadings   Your name property has nothing to do with Enum internals     To address the questions concerns in the comments   The enum s  builtin   implicitly declared  valueOf String name  method will look up an enum constant with that exact name  If your input is  columnHeadings   you have  at least  three choices    Forget about the naming conventions for a bit and just name your constants as it makes most sense  enum PropName   contents  columnHeadings        This is obviously the most convenient  Convert your camelCase input into UPPER SNAKE CASE before calling valueOf  if you re really fond of naming conventions  Implement your own lookup method instead of the builtin valueOf to find the corresponding constant for an input  This makes most sense if there are multiple possible mappings for the same set of constants

User · Answer

That s because you defined your own version of name for your enum  and getByName doesn t use that   getByName  COLUMN HEADINGS   would probably work

User · Answer

I had parsing enum problem when i was trying to pass Nullable Enum that we get from Backend  Of course it was working when we get value  but it was problem when the null comes up      java lang IllegalArgumentException  No enum constant   Also the problem was when we at Parcelize read moment write some short if   My solution for this was   1 Create companion object with parsing method   enum class CarsType        Json name    SMALL       SMALL       Json name    BIG       BIG       companion object           fun nullableValueOf name  String     when  name                null - gt  null             else - gt  valueOf name                      2  In Parcerable read place use it like this  data class CarData      val carId  String    null      val carType  CarsType       val data  String      Parcelable       constructor parcel  Parcel    this          parcel readString            CarsType nullableValueOf parcel readString             parcel readString

User · Answer

Instead of defining  COLUMN HEADINGS  columnHeadings    Try defining it as   COLUMNHEADINGS  columnHeadings    Then when you call getByName String name  method  call it with the upper-cased String like this  getByName myStringVariable toUpperCase     I had the same problem as you  and this worked for me

[java] What is the reason for java.lang.IllegalArgumentException: No enum const class even though iterating through values() works just fine?

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