What causes "e (wrapped exception)" in pentaho/pentaho-kettle?

Inspect the cause chain (KettleException.getCause()) for the real TransformerException message

pentaho/pentaho-kettle · error · KettleException

e (wrapped exception)

Error message

e (wrapped exception)

What it means

After building the in-memory DOM, AddXML serializes it via a Transformer (getSerializer().transform). If the javax.xml.transform Transformer throws TransformerException (or any other Exception), processRow wraps it in a KettleException with no additional message — the cause carries all detail. The error means DOM-to-string serialization failed at runtime.

Solutions

Inspect the cause chain (KettleException.getCause()) for the real TransformerException message
Check for conflicting JAXP transformer implementations (Xalan/Saxon JARs) on the classpath and remove duplicates
Verify the step's encoding setting is a supported charset name
Pin a known-good transformer factory via -Djavax.xml.transform.TransformerFactory system property

Example fix

// before (diagnosing)
catch (KettleException ke) { logError(ke.getMessage()); }
// after
catch (KettleException ke) { logError("XML transform failed", ke); logError("Root cause:", ke.getCause()); }

Defensive patterns

Strategy: try-catch

Validate before calling

try {
  Transformer t = TransformerFactory.newInstance().newTransformer();
  t.transform(new DOMSource(DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument()), new StreamResult(new StringWriter()));
} catch (TransformerException e) {
  failFast("JAXP transformer environment broken: " + e.getMessage());
}

Try / catch

try { step.processRow(); } catch (KettleException ke) {
  Throwable cause = ke.getCause();
  if (cause instanceof TransformerException) {
    logError("XML serialization failed: " + cause.getMessage(), cause);
  }
}

Prevention

Keep a single JAXP TransformerFactory implementation on the classpath
Use standard encodings (UTF-8) in step settings
Smoke-test transformations on the target JDK before deployment

When it happens

Trigger: processRow calls this.getSerializer().transform(domSource, new StreamResult(sw)) and the transformer fails — e.g. transformer factory misconfiguration, encoding problems, or DOM state the transformer cannot serialize.

Common situations: JDK/JAXP transformer factory conflicts (e.g. wrong Xalan/Saxon on classpath); unsupported output encoding set in step settings; serializer plugin lookup returning a broken serializer.

Related errors

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/d308e5a1feb495f3. Report an issue: GitHub.

Appendix: source

Thrown at plugins/xml/core/src/main/java/org/pentaho/di/trans/steps/addxml/AddXML.java:157

            Element e = xmldoc.createElement( element );
            Node n = xmldoc.createTextNode( value );
            e.appendChild( n );
            root.appendChild( e );
          } else {
            Node n = xmldoc.createTextNode( value );
            root.appendChild( n );
          }
        }
      }
    }

    StringWriter sw = new StringWriter();
    DOMSource domSource = new DOMSource( xmldoc );
    try {
      this.getSerializer().transform( domSource, new StreamResult( sw ) );

    } catch ( TransformerException e ) {
      throw new KettleException( e );
    } catch ( Exception e ) {
      throw new KettleException( e );
    }

    Object[] outputRowData = RowDataUtil.addValueData( r, getInputRowMeta().size(), sw.toString() );

    putRow( data.outputRowMeta, outputRowData );

    return true;
  }

  private String formatField( ValueMetaInterface valueMeta, Object valueData, XMLField field )
    throws KettleValueException {
    String retval = "";
    if ( field == null ) {
      return "";
    }

View on GitHub (pinned to f3058517a1)