JetBrains/intellij-community · error · IllegalArgumentException

Row %d failed: hierarchicalIdx cannot be null

Error message

Row %d failed: hierarchicalIdx cannot be null

What it means

HierarchicalColumnsDataGridModel.getValue(row, hierarchicalIdx) throws IllegalArgumentException when the hierarchical column path passed by the caller is null. The path (int[] of nesting levels) is mandatory: validateHierarchicalIndex checks it before any traversal of the row's nested value arrays.

Source

Thrown at grid/core-impl/src/datagrid/HierarchicalColumnsDataGridModel.java:404

        Object value = tryExtractValueByHierarchicalIndex(rowValues, columnPath, rowIdx+1);

        return value == null ? null : value.toString();
      })
      .limit(200)
      .collect(Collectors.toList());

    return CsvImportUtil.getPreferredTypeMergerBasedOnContent(
      values, STRING_MERGER, INTEGER_MERGER, BIG_INTEGER_MERGER, DOUBLE_MERGER, BOOLEAN_MERGER);
  }

  private static Object getValue(GridRow row, int[] hierarchicalIdx) {
    validateHierarchicalIndex(hierarchicalIdx, row.getRowNum());
    return tryExtractValueByHierarchicalIndex(GridRow.getValues(row), hierarchicalIdx, row.getRowNum());
  }

  private static void validateHierarchicalIndex(int[] hierarchicalIdx, int rowNum) {
    if (hierarchicalIdx == null) {
      throw new IllegalArgumentException(
        String.format("Row %d failed: hierarchicalIdx cannot be null", rowNum)
      );
    }

    if (hierarchicalIdx.length == 0) {
      throw new IllegalArgumentException(
        String.format("Row %d access failed: hierarchicalIdx cannot be empty", rowNum)
      );
    }
  }

  private static @Nullable Object tryExtractValueByHierarchicalIndex(Object[] topLevelValues, int[] hierarchicalIdx, int rowNum) {
    try {
      return extractValueByHierarchicalIndex(topLevelValues, hierarchicalIdx);
    } catch (IndexOutOfBoundsException | NullPointerException | IllegalArgumentException e) {
      throw new RuntimeException(String.format("Row %d access failed: %s", rowNum, e.getMessage()), e);
    }
  }

View on GitHub (pinned to be881553f2)

Solutions

1. Compute the hierarchical index from the column (e.g. column's path in the columns hierarchy) and pass a non-null int[].
2. Add a null check at the call site and fail fast with context about which column produced the null path.
3. For flat access, use the top-level value APIs instead of hierarchical ones.

Example fix

// before
Object v = getValue(row, null);

// after
int[] path = column.getHierarchicalIdx(); // never null for live columns
Object v = getValue(row, path);

if (hierarchicalIdx == null) throw new IllegalArgumentException("hierarchicalIdx required for column " + column.getName());

static boolean hasHierarchicalIdx(@Nullable int[] idx) { return idx != null; }

When it happens

Trigger: Calling getValue/setValue style accessors with a null int[] hierarchical index — commonly a caller that resolved the path from a GridColumn whose hierarchy was not initialized, or a default-parameter null slipping through.

Common situations: New code paths (custom renderers, exporters) that assume flat columns and pass null; refactoring that makes path computation optional without a fallback.

Related errors

• Row %d access failed: hierarchicalIdx cannot be empty
• Row %d access failed: %s
• Access by hierarchical idx %s failed: Index out of bounds at
• Access by hierarchical idx %s failed: Encountered a null ele
• Access by hierarchical idx %s failed: Encountered an unexpec

AI-assisted analysis of JetBrains/intellij-community@be881553f2 (2026-08-14). Data as JSON: /api/errors/44f3eea1e5b9be0d. Report an issue: GitHub.