apache/hadoop · error · IOException

Unexpected: {type}

Error message

Unexpected: {type}

What it means

Error "Unexpected: {type}" thrown in apache/hadoop.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/lib/join/Parser.java:187

        case StreamTokenizer.TT_EOF:
        case StreamTokenizer.TT_EOL:
          return null;
        case StreamTokenizer.TT_NUMBER:
          return new NumToken(tok.nval);
        case StreamTokenizer.TT_WORD:
          return new StrToken(TType.IDENT, tok.sval);
        case '"':
          return new StrToken(TType.QUOT, tok.sval);
        default:
          switch (type) {
            case ',':
              return new Token(TType.COMMA);
            case '(':
              return new Token(TType.LPAREN);
            case ')':
              return new Token(TType.RPAREN);
            default:
              throw new IOException("Unexpected: " + type);
          }
      }
    }
  }

@SuppressWarnings("unchecked")
@InterfaceAudience.Public
@InterfaceStability.Evolving
public abstract static class Node extends ComposableInputFormat {
    /**
     * Return the node type registered for the particular identifier.
     * By default, this is a CNode for any composite node and a WNode
     * for "wrapped" nodes. User nodes will likely be composite
     * nodes.
     * @see #addIdentifier(java.lang.String, java.lang.Class[], java.lang.Class, java.lang.Class)
     * @see CompositeInputFormat#setFormat(org.apache.hadoop.mapred.JobConf)
     */
    static Node forIdent(String ident) throws IOException {

View on GitHub (pinned to 2add963021)

Solutions

1. Check the join expression for an unexpected token of the reported type; remove or replace it with a token valid at that position.
2. Review the composite join grammar and rewrite the expression so tokens appear in a valid order.

When it happens

Trigger: Thrown by Parser.Token when code reaches an unexpected token type branch that should not occur for a validly lexed expression. Usually indicates a malformed or corrupted join expression string; re-check the expression passed to the join parser.

Common situations: Unbalanced parentheses, stray operators, or a malformed identifier in the join expression string.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/13ca5ed804536bd6. Report an issue: GitHub.