Java Lambdas Tips

Creating a lookup method for an Enum

Without lambdas:

public enum Type {
     
     INFO,
     WARNING,
     ERROR;

     final static Map<String, Type> lookup = new HashMap<String, Type>();
     
     static {
      for(Type type : Type.values()) {
       lookup.put(type.name().toLowerCase(), type);
      }
     }

       
     public static Type of(String value){
         Type val = lookup.get(value == null ? null : value.toLowerCase());
         if(val == null){
             val = ERROR;
         }
         return val;
     }
}

With lambda:

public enum Type {
     INFO,
     WARNING,
     ERROR;

     final static Map<String, Type> lookup = Arrays.stream(Type.values())
          .collect(Collectors.toMap(t -> t.name().toLowerCase(), Function.identity()));

     public static Type of(String value){
         Type val = lookup.get(value == null ? null : value.toLowerCase());
         if(val == null){
            val = ERROR;
         }
         return val;
     }
}