redis/jedis · error · InstantiationError

Must not instantiate this class

Error message

Must not instantiate this class

What it means

SearchBuilderFactory is a static-constants-only factory class; its private constructor throws InstantiationError to forbid instantiation. It only fires if code explicitly tries to construct the class.

Solutions

1. Use the static builders directly, e.g. SearchBuilderFactory.SEARCH or SearchBuilderFactory.PROFILE
2. Exclude utility/factory classes from reflective instantiation
3. Delete any instantiation code

Example fix

// before
SearchBuilderFactory f = new SearchBuilderFactory();
Builder b = f.SEARCH;
// after
Builder b = SearchBuilderFactory.SEARCH;

When it happens

Trigger: Writing new SearchBuilderFactory(); reflective instantiation by frameworks or Class.newInstance; accidental bean-scanning instantiation.

Common situations: Incorrect copy of factory-class usage; reflection-based tests or DI containers scanning and instantiating all classes in the package.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Must not instantiate this class
• Must not instantiate this class
• Must not instantiate this class
• Must not instantiate this class
• Setting null as field attribute is not allowed.

AI-assisted analysis of redis/jedis@6dac31d4c2 (2026-09-08). Data as JSON: /api/errors/7f03f4a1a9bfb9d6. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/redis/clients/jedis/search/SearchBuilderFactory.java:85

        String header = STRING.build(rawElements.get(0));
        if (!TERM.equals(header)) {
          throw new IllegalStateException("Unrecognized header: " + header);
        }
        String term = STRING.build(rawElements.get(1));

        List<List<Object>> list = (List<List<Object>>) rawElements.get(2);
        Map<String, Double> entries = new LinkedHashMap<>(list.size());
        list.forEach(entry -> entries.put(STRING.build(entry.get(1)), BuilderFactory.DOUBLE.build(entry.get(0))));

        returnTerms.put(term, entries);
      }
      return returnTerms;
    }
  };

  private SearchBuilderFactory() {
    throw new InstantiationError("Must not instantiate this class");
  }
}

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