redis/jedis · error · IllegalArgumentException

Must have at least one tag

Error message

Must have at least one tag

What it means

Values.tags(String... tags) builds a RediSearch tag-filter Value from one or more tag strings. Because a tag filter with zero tags is meaningless in RediSearch query syntax, the method rejects an empty varargs array with IllegalArgumentException("Must have at least one tag").

Solutions

1. Guard the call site: only call Values.tags when the tag array is non-empty.
2. Skip adding the tag filter node entirely when the list is empty.
3. If at least one tag is always required by your domain, validate input earlier (e.g. at request parsing) with a clearer message.

Example fix

// before
Query.Node n = new QueryBuilder().addFilter(Values.tags(selectedTags.toArray(new String[0])));
// after
if (!selectedTags.isEmpty()) {
  qb.addFilter(Values.tags(selectedTags.toArray(new String[0])));
}

if (tags == null || tags.length == 0) {
  throw new IllegalArgumentException("At least one tag is required for a tag filter");
}
Value v = Values.tags(tags);

boolean hasTags(String[] tags) {
  return tags != null && tags.length > 0;
}

try {
  value = Values.tags(tagArray);
} catch (IllegalArgumentException e) {
  log.warn("Skipping empty tag filter: {}", e.getMessage());
}

When it happens

Trigger: Calling Values.tags() with no arguments, or passing an empty String[] / empty collection converted to an array (e.g. Values.tags(myList.toArray(new String[0])) where the list is empty).

Common situations: Building tag filters from user-selected filter chips or request parameters where the user selected none; dynamic query construction where an empty tags list flows into Values.tags instead of being skipped.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

• DriverInfo must not be null
• DIALECT=0 cannot be set.
• DIALECT=0 cannot be set.
• REDUCE COLLECT cannot mix FIELDS * with explicit field names
• Must not instantiate this class

AI-assisted analysis of redis/jedis@6dac31d4c2 (2026-09-08). Data as JSON: /api/errors/9b8ef323fd7e5156. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/redis/clients/jedis/search/querybuilder/Values.java:90

  public static RangeValue le(double d) {
    return lt(d).inclusiveMax(true);
  }

  public static RangeValue le(int d) {
    return lt(d).inclusiveMax(true);
  }

  public static RangeValue ge(double d) {
    return gt(d).inclusiveMin(true);
  }

  public static RangeValue ge(int d) {
    return gt(d).inclusiveMin(true);
  }

  public static Value tags(String... tags) {
    if (tags.length == 0) {
      throw new IllegalArgumentException("Must have at least one tag");
    }
    StringJoiner sj = new StringJoiner(" | ");
    for (String s : tags) {
      sj.add(s);
    }
    return new Value() {
      @Override
      public String toString() {
        return "{" + sj.toString() + "}";
      }
    };
  }
}

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