[CXF-9037] NPE when using com.ctc.wstx.returnNullForDefaultNamespace=true

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.5.8, 3.6.3, 4.0.4
• Fix Version/s: 3.5.10, 3.6.5, 4.0.6
• Component/s: Core
• Estimated Complexity: Unknown
• Assignee: Andriy Redko
• Reporter: Gordon Freeman
• Created: 13/Jul/24 08:54
• Updated: 20/Jul/24 01:39
• Resolved: 20/Jul/24 01:39

Description

I am using custom out interceptor, which make xsl transformation to serialize some elements as CDATA, my code was inspired by org.apache.cxf.feature.transform.XSLTOutInterceptor.

But if I set property com.ctc.wstx.returnNullForDefaultNamespace=true, the I've got an NPE. This property is required to fix some other issues with xml generation (without it I've got empty namespaces xmlns="" in some cases).

The code bellow is the minimum example of NPE, using org.apache.cxf.staxutils.StaxSource.

 

Exception in thread "main" java.lang.NullPointerException: Cannot invoke "String.equals(Object)" because "prefix" is null 
       at net.sf.saxon.event.ReceivingContentHandler.startPrefixMapping(ReceivingContentHandler.java:300) 
       at org.apache.cxf.staxutils.StaxSource.parse(StaxSource.java:145) 
       at org.apache.cxf.staxutils.StaxSource.parse(StaxSource.java:259) 
       at net.sf.saxon.resource.ActiveSAXSource.deliver(ActiveSAXSource.java:192) 
       at net.sf.saxon.event.Sender.send(Sender.java:104) 
       at net.sf.saxon.jaxp.IdentityTransformer.transform(IdentityTransformer.java:364)

package test;

import com.ctc.wstx.stax.WstxInputFactory;
import org.apache.cxf.staxutils.StaxSource;

import javax.xml.transform.OutputKeys;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stax.StAXSource;
import javax.xml.transform.stream.StreamResult;
import java.io.ByteArrayInputStream;
import java.io.StringWriter;
import java.nio.charset.StandardCharsets;

public class NpeTest
{
    public static void main(String[] args) throws Exception
    {
        String bodyXml = "<?xml version=\"1.0\"?>\n" +
                "<soap:Envelope xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\">\n" +
                "  <soap:Body>\n" +
                "    <testReq xmlns=\"http://test.com/test\">\n" +
                "        <reqBody>&lt;&lt;&lt;&lt;&lt;</reqBody>\n" +
                "    </testReq>\n" +
                "  </soap:Body>\n" +
                "</soap:Envelope>\n";

        System.setProperty("com.ctc.wstx.returnNullForDefaultNamespace", "true");

        WstxInputFactory factory = new WstxInputFactory();
        Source beforeSource = new StaxSource(factory.createXMLStreamReader(new ByteArrayInputStream(bodyXml.getBytes(StandardCharsets.UTF_8))));
//        Source beforeSource = new StAXSource(factory.createXMLStreamReader(new ByteArrayInputStream(bodyXml.getBytes(StandardCharsets.UTF_8))));
        System.out.println(save(beforeSource));
    }

    public static String save(Source beforeSource) throws Exception
    {
        StringWriter writer = new StringWriter();
        StreamResult result = new StreamResult(writer);

        TransformerFactory tf = TransformerFactory.newInstance();

        Transformer transformer = tf.newTransformer();
        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
        transformer.setOutputProperty(OutputKeys.STANDALONE, "yes");
        transformer.setOutputProperty(OutputKeys.CDATA_SECTION_ELEMENTS, "Q{http://test.com/test}reqBody");
        transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");

        transformer.transform(beforeSource, result);

        return writer.toString();
    }
}

The stacktrace from my project is:

java.lang.NullPointerException
        at net.sf.saxon.event.ReceivingContentHandler.startPrefixMapping(ReceivingContentHandler.java:301)
        at org.apache.cxf.staxutils.StaxSource.parse(StaxSource.java:145)
        at org.apache.cxf.staxutils.StaxSource.parse(StaxSource.java:259)
        at net.sf.saxon.resource.ActiveSAXSource.deliver(ActiveSAXSource.java:190)
        at net.sf.saxon.event.Sender.send(Sender.java:105)
        at net.sf.saxon.jaxp.IdentityTransformer.transform(IdentityTransformer.java:364)
        at org.apache.cxf.feature.transform.XSLTUtils.transform(XSLTUtils.java:57)
        at org.apache.cxf.feature.transform.XSLTOutInterceptor$XSLTCachedOutputStreamCallback.onClose(XSLTOutInterceptor.java:165)
        at org.apache.cxf.io.CachedOutputStream.close(CachedOutputStream.java:219)
        at org.apache.cxf.transport.AbstractConduit.close(AbstractConduit.java:56)
        at org.apache.cxf.transport.http.HTTPConduit.close(HTTPConduit.java:688)
        at org.apache.cxf.interceptor.MessageSenderInterceptor$MessageSenderEndingInterceptor.handleMessage(MessageSenderInterceptor.java:63)
        at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:307)
        at org.apache.cxf.endpoint.ClientImpl.doInvoke(ClientImpl.java:530)
        at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:441)
        at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:356)
        at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:314)
        at org.apache.cxf.frontend.ClientProxy.invokeSync(ClientProxy.java:96)
        at org.apache.cxf.jaxws.JaxWsClientProxy.invoke(JaxWsClientProxy.java:140)

Issue Links

• links to: GitHub Pull Request #1962