pentaho/pentaho-kettle · error · RuntimeException

The function call touch requires 1 valid argument.

Error message

The function call touch requires 1 valid argument.

What it means

touch() creates a file or updates its last-modified timestamp, and requires exactly one argument that is a String path. This RuntimeException is thrown when the argument count is not 1 or the argument is not a String (the code checks ArgList.length == 1 && ArgList[0] instanceof String).

Solutions

1. Call touch with exactly one String argument: touch('/path/to/file.txt').
2. Convert non-string fields first, e.g. touch(fieldName + '') or use a string-typed field.
3. Build the full path into a single JavaScript string variable before calling touch().
4. Catch the RuntimeException in script if the path may be dynamic and validate it beforehand.

Example fix

// before
touch(fileId); // numeric field
// after
touch('/data/export/' + fileId + '.txt');

if (path == null || typeof path !== 'string' || path.length === 0) throw new RuntimeException('touch needs one non-empty string path');
touch(path);

function isPath(v) { return v != null && (typeof v === 'string' || v instanceof java.lang.String); }

try { touch(p); } catch (e) { logError('touch failed: ' + e.message); }

When it happens

Trigger: Calling touch() with zero arguments, multiple arguments, or a non-String argument such as a number, Date, or JavaScript null.

Common situations: Passing a transformation field that is not a string type; forgetting the filename argument; concatenating path parts outside the call and accidentally passing extra arguments.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• The function call fileExists requires 1 valid argument.
• The function call copyFile is not valid.
• The function call execProcess is not valid.
• The function call getLastModifiedTime is not valid.
• AccessInputMeta.Exception.FileDoesNotExist

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/65b47f608a392b35. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/steps/script/ScriptAddedFunctions.java:961

        throw new RuntimeException( e.toString() );
      }
    } else {
      throw new RuntimeException( "The function call str2RegExp requires 2 arguments." );
    }
    return strArr;
  }

  public static void touch( ScriptEngine actualContext, Bindings actualObject, Object[] ArgList,
    Object FunctionContext ) {
    try {
      if ( ArgList.length == 1 && !isNull( ArgList[0] ) && !isUndefined( ArgList[0] ) ) {
        File file = new File( (String) ArgList[0] );
        boolean success = file.createNewFile();
        if ( !success ) {
          file.setLastModified( System.currentTimeMillis() );
        }
      } else {
        throw new RuntimeException( "The function call touch requires 1 valid argument." );
      }
    } catch ( Exception e ) {
      throw new RuntimeException( e.toString() );
    }
  }

  public static Object fileExists( ScriptEngine actualContext, Bindings actualObject, Object[] ArgList,
    Object FunctionContext ) {
    try {
      if ( ArgList.length == 1 && !isNull( ArgList[0] ) && !isUndefined( ArgList[0] ) ) {
        if ( ArgList[0].equals( null ) ) {
          return null;
        }
        File file = new File( (String) ArgList[0] );
        return Boolean.valueOf( file.isFile() );
      } else {
        throw new RuntimeException( "The function call fileExists requires 1 valid argument." );
      }

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