redis/jedis · error · InstantiationError

Must not instantiate this class

Error message

Must not instantiate this class

What it means

RediSearchUtil is a static-only utility class; its private constructor deliberately throws InstantiationError to prevent instantiation. It is not meant to be thrown at call sites — it only fires if you (or reflection) try to new RediSearchUtil().

Solutions

1. Use the static methods directly: RediSearchUtil.toStringMap(...) / RediSearchUtil.escape(...) / unescape(...)
2. Exclude the class from reflection-based instantiation scans
3. Remove any code that instantiates utility classes

Example fix

// before
RediSearchUtil util = new RediSearchUtil();
String escaped = util.escape(text);
// after
String escaped = RediSearchUtil.escape(text);

When it happens

Trigger: Writing new RediSearchUtil(); invoking the constructor reflectively (e.g. frameworks instantiating classes); serialization/deserialization libraries attempting to construct it.

Common situations: Copying utility-class patterns incorrectly; reflection-based bean instantiation or Class.newInstance scanning 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/517a154279f0b2fa. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/redis/clients/jedis/search/RediSearchUtil.java:114

    char[] chars = text.toCharArray();

    StringBuilder sb = new StringBuilder();
    for (char ch : chars) {
      if (ESCAPE_CHARS.contains(ch)
          || (querying && ch == ' ')) {
        sb.append("\\");
      }
      sb.append(ch);
    }
    return sb.toString();
  }

  public static String unescape(String text) {
    return text.replace("\\", "");
  }

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

View on GitHub (pinned to 6dac31d4c2)