apache/hadoop · error · IllegalArgumentException

Null opt

Error message

Null opt

What it means

Options.CreateOpts.getOpt(clazz, opts) requires a non-null varargs array of create options. Passing null (the array itself, not an element) throws IllegalArgumentException('Null opt') before scanning.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/Options.java:171

    
    public static class CreateParent extends CreateOpts {
      private final boolean createParent;
      protected CreateParent(boolean createPar) {
        createParent = createPar;}
      public boolean getValue() { return createParent; }
    }

    
    /**
     * Get an option of desired type
     * @param clazz is the desired class of the opt
     * @param opts - not null - at least one opt must be passed
     * @return an opt from one of the opts of type theClass.
     *   returns null if there isn't any
     */
    static <T extends CreateOpts> T getOpt(Class<T> clazz, CreateOpts... opts) {
      if (opts == null) {
        throw new IllegalArgumentException("Null opt");
      }
      T result = null;
      for (int i = 0; i < opts.length; ++i) {
        if (opts[i].getClass() == clazz) {
          if (result != null) {
            throw new IllegalArgumentException("multiple opts varargs: " + clazz);
          }

          @SuppressWarnings("unchecked")
          T t = (T)opts[i];
          result = t;
        }
      }
      return result;
    }
    /**
     * set an option
     * @param newValue  the option to be set

View on GitHub (pinned to 2add963021)

Solutions

1. Pass an empty array (new CreateOpts[0]) instead of null
2. Fix option-array builders to never return null; return an empty array

Example fix

// before
T opt = CreateOpts.getOpt(clazz, null);
// after
T opt = CreateOpts.getOpt(clazz, new CreateOpts[0]);   // never pass a null varargs array

CreateOpts[] safe = (opts == null) ? new CreateOpts[0] : opts;

When it happens

Trigger: Calling getOpt with an explicitly null CreateOpts... array — e.g. a caller built its option array conditionally and the builder returned null, or reflection/bridging code passed null through.

Common situations: Helper APIs assembling option arrays that default to null, defensive `opts != null ? opts : null` bugs, conditional builder methods.

Related errors

• Permissions must not be null
• Progress must not be null
• multiple opts varargs: ${clazz}
• tokenStr cannot be null
• url cannot be NULL

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/2f7517ad91c8df1d. Report an issue: GitHub.