Hi Daniel,

Many thanks for your insights !

Regarding the in-efficiency of approach taken, i completely agree. However, i 
dont see any other solution,  i will tell you my complete problem that i am 
trying to solve.
May be you could advise for a better solution.

Problem :
Post CXF upgrade to 3.2.7 from a quite old version, MapCodec interceptor 
enforces, that a tag called "<wsa:MessageID>" should be present in CXF request, 
if absent CXF drops the request. Unfortunately  some customers of our 
webservice send  "<wsa:MessageID>" , others don't.

Solution :
Examine the request, if "<wsa:MessageID>" is absent add it in the headers !

Solution Implementation :
Add 2 interceptors to the IN interceptor chain.
First intereptor detects if a  "<wsa:MessageID>"  header is absent, if absent 
then it adds a "transformInterceptor" in the interceptor chain to append a 
bogus "<wsa:MessageID>" header

Solution Code (Also attached):
Here is the code for first interceptor/MessageIdDetector

public class MessageIdDetector extends AbstractSoapInterceptor {

  private static final String CXF_TRANSFORM_MESSAGE_ID_ELEMENT_KEY =
      "{http://schemas.xmlsoap.org/soap/envelope/}Header/";;
  private static final String CXF_TRANSFORM_MESSAGE_ID_ELEMENT_VALUE =
      
"{http://schemas.xmlsoap.org/ws/2004/08/addressing}MessageID=http://www.w3.org/2005/08/addressing/unspecified";;


  public MessageIdDetector() {
    super(Phase.READ);
    addAfter(ReadHeadersInterceptor.class.getName());
  }

  @Override
  public void handleMessage(SoapMessage message) throws Fault {
    QName messageIdQname = new 
QName("http://schemas.xmlsoap.org/ws/2004/08/addressing";, "MessageID");
    boolean isMessageIDheaderPresent = message.hasHeader(messageIdQname);
    if (!isMessageIDheaderPresent) {
      addMessageIdTransformInInterceptor(message);
    }
  }

  /**
   * Adds a transform interceptor to the chain in order to transform the message
   *
   * @param message
   */
  private void addMessageIdTransformInInterceptor(Message message) {
    TransformInInterceptor transformInterceptor = new 
TransformInInterceptor(Phase.PRE_PROTOCOL);
    Map<String, String> inAppendMap = new HashMap<>();
    // this map contains the messageID element that we want to append to message
    inAppendMap.put(CXF_TRANSFORM_MESSAGE_ID_ELEMENT_KEY, 
CXF_TRANSFORM_MESSAGE_ID_ELEMENT_VALUE);
    transformInterceptor.setInAppendElements(inAppendMap);
    transformInterceptor.addBefore(SAAJInInterceptor.class.getName());
    // add the interceptor to the current chain
    message.getInterceptorChain()
        .add(transformInterceptor);
  }

}

Why this solution fails and i have to opt for the in-efficient approach ?

As per above code when the incoming request doesn't have the "<wsa:MessageID>", 
transformInterceptor is added and post execution of first interceptor,

Following is the interceptor chain :

  receive [PolicyInInterceptor, AttachmentInInterceptor]
  pre-stream [CertConstraintsInterceptor]
  post-stream [StaxInInterceptor]
  read [SAAJPreInInterceptor, ReadHeadersInterceptor, MessageIdDetector, 
WSDLGetInterceptor, SoapActionInInterceptor, StartBodyInterceptor]
  pre-protocol [TransformInInterceptor, SAAJInInterceptor, MAPCodec, 
WSS4JInInterceptor, MustUnderstandInterceptor]
  post-protocol [CheckFaultInterceptor]
  unmarshal [DocLiteralInInterceptor, SoapHeaderInterceptor]
  pre-logical [MAPAggregatorImpl, OneWayProcessorInterceptor]
  post-logical [MessageModeInInterceptor]
  pre-invoke [StaxInEndingInterceptor, SwAInInterceptor]
  invoke [ServiceInvokerInterceptor]
  post-invoke [OutgoingChainInterceptor]

However, CXF fails with the following exception :

11:18:27,068 WARNING [org.apache.cxf.phase.PhaseInterceptorChain] 
(http-127.0.0.1:8080-1) Interceptor for <redacted> has thrown exception, 
unwinding now: java.util.NoSuchElementException
        at java.util.LinkedList.removeFirst(LinkedList.java:270) 
[rt.jar:1.8.0_191]
        at 
org.apache.cxf.staxutils.transform.DelegatingNamespaceContext.up(DelegatingNamespaceContext.java:50)
 [cxf-core-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.staxutils.transform.InTransformReader.next(InTransformReader.java:171)
 [cxf-core-3.2.7.jar:3.2.7]
        at org.apache.cxf.staxutils.StaxUtils.copy(StaxUtils.java:793) 
[cxf-core-3.2.7.jar:3.2.7]

I have attched full stacktrace in the attachments.

Now if i move the transformation step prior to ReadHeadersInterceptor the exact 
same transformInterceptor works, but i loose the access to message.getHeaders() 
and hence the in-efficient approach.

Please advise if something comes to your mind, OR a better approach that i can 
take.

Many thanks for advsing on my queries 🙂!
Warm Regards,
Varun SINGHAL



________________________________
From: Daniel Kulp <dk...@apache.org>
Sent: Tuesday, March 5, 2019 6:55 PM
To: users@cxf.apache.org; Varun Singhal
Subject: Re: [Reading CXF message content] What is CachedOutputStream's primary 
purpose and how its different than DelegatingInputStream ?

Well, my first thought is that for what you are trying to do, you are doing it 
in a very in-efficient manner.   :)

For the most part, you would be better off adding an interceptor to the 
beginning of the PRE_PROTOCOL phase.   At that point, you could do:


((SoapMessage)message).getHeaders()

To get the list of headers that have already been parsed.  You could modify the 
contents of the header objects at that point.  This would not break streaming 
of the body and would perform significantly better, particularly for large 
requests.  Your method involves parsing the entire message twice, potentially 
storing larger  messages on disk.


Now, to answer the specific question2:

Query#1 :
If CachedOutputStream  is used for creating a re-readable inputStream why the 
name is so misleading ? (It doesn't even have input word in it)

CachedOutputStream is not just used for that.    It’s not required to ever get 
an InputStream from it.    There is a writeCacheTo method that can be used to 
write everything to a different output stream.   There is a getBytes() call for 
getting everything as a byte[], etc….    Its primary use case is via the 
CachedOutputStreamCallback objects.   In some cases, we use the 
CachedOutputStream to start writing, and once a certain threshold is hit, the 
callback is triggered and the cache is flushed to a real output stream, and the 
CachedOutputStream is replaced with the real output stream.      Thus, if the 
amount of data never hits the threshold, we can optimize certain cases, but if 
it does, we go another route.


Query#2 :
For the requirement of re-readable inputStream, is CachedOutputStream  the best 
candidate, why not 
DelegatingInputStream<https://cxf.apache.org/javadoc/latest/org/apache/cxf/io/DelegatingInputStream.html>,
 if yes would you be kind enough to provide a working code snippet of same ?

CachedOutputStream is likely the best option at this point, but see above for 
your specific use case.

Dan





On Mar 5, 2019, at 10:30 AM, Varun Singhal 
<varunsingha...@live.com<mailto:varunsingha...@live.com>> wrote:

Hi guys,

Can anyone advise on the below queries, please ?

I really want to understand if my understanding is flawed ☹

Many thanks !

Warm Regards,
Varun SINGHAL

________________________________
From: Varun Singhal
Sent: Tuesday, March 5, 2019 12:09:24 AM
To: users@cxf.apache.org<mailto:users@cxf.apache.org>
Subject: [Reading CXF message content] What is CachedOutputStream's primary 
purpose and how its different than DelegatingInputStream ?

Hi all,

Greetings !

I have designed a interceptor that runs in RECEIVE phase and takes a decision 
whether to modify the header of an incoming SOAP request OR not.
It does so by reading the message's contents and parsing it into a XML document 
instance.

Here is the code:

     //get message as stream
     InputStream ipStream = message.getContent(InputStream.class);
     CachedOutputStream cos = new CachedOutputStream();
     //create a re-readable inputstream
     IOUtils.copy(ipStream, cos);
     ipStream.close();
     cos.flush();
     //set the new inputstream
     message.setContent(InputStream.class, cos.getInputStream());
    //XML document instance
     DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
     DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
     doc = dBuilder.parse(cos.getInputStream());
     cos.close();
     if (doc != null) {
         takeDecisionOnHeaderModification(doc);
       }
     }

The code works fine.
As you can make out i needed a re-readable `inputStream` otherwise successive 
application code/interceptors would have empty input stream.
so i used CachedOutputStream because cos.getInputStream() is re-readable.

Here are my queries about this approach :

Query#1 :
If CachedOutputStream  is used for creating a re-readable inputStream why the 
name is so misleading ? (It doesn't even have input word in it)

Query#2 :
For the requirement of re-readable inputStream, is CachedOutputStream  the best 
candidate, why not 
DelegatingInputStream<https://cxf.apache.org/javadoc/latest/org/apache/cxf/io/DelegatingInputStream.html>,
 if yes would you be kind enough to provide a working code snippet of same ?

I will be very grateful if anyone could shed light on these queries ?

Many Thanks !

Warm Regards,

Varun SINGHAL


--
Daniel Kulp
dk...@apache.org<mailto:dk...@apache.org> - http://dankulp.com/blog
Talend Community Coder - http://talend.com<http://coders.talend.com>

11:18:27,068 WARNING [org.apache.cxf.phase.PhaseInterceptorChain] 
(http-127.0.0.1:8080-1) Interceptor for <redacted> has thrown exception, 
unwinding now: java.util.NoSuchElementException
        at java.util.LinkedList.removeFirst(LinkedList.java:270) 
[rt.jar:1.8.0_191]
        at 
org.apache.cxf.staxutils.transform.DelegatingNamespaceContext.up(DelegatingNamespaceContext.java:50)
 [cxf-core-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.staxutils.transform.InTransformReader.next(InTransformReader.java:171)
 [cxf-core-3.2.7.jar:3.2.7]
        at org.apache.cxf.staxutils.StaxUtils.copy(StaxUtils.java:793) 
[cxf-core-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.binding.soap.saaj.SAAJInInterceptor.handleMessage(SAAJInInterceptor.java:245)
 [cxf-rt-bindings-soap-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.binding.soap.saaj.SAAJInInterceptor.handleMessage(SAAJInInterceptor.java:81)
 [cxf-rt-bindings-soap-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:308)
 [cxf-core-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
 [cxf-core-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:267)
 [cxf-rt-transports-http-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:234)
 [cxf-rt-transports-http-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:208)
 [cxf-rt-transports-http-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:160)
 [cxf-rt-transports-http-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:216)
 [cxf-rt-transports-http-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:301)
 [cxf-rt-transports-http-3.2.7.jar:3.2.7]
        at 
org.apache.cxf.transport.servlet.AbstractHTTPServlet.doPost(AbstractHTTPServlet.java:220)
 [cxf-rt-transports-http-3.2.7.jar:3.2.7]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:754) 
[jboss-servlet-api_3.0_spec-1.0.2.Final-redhat-2.jar:1.0.2.Final-redhat-2]
        at 
org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:276)
 [cxf-rt-transports-http-3.2.7.jar:3.2.7]
        at 
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:295)
 [jbossweb-7.5.27.Final-redhat-1.jar:7.5.27.Final-redhat-1]
        at 
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
 [jbossweb-7.5.27.Final-redhat-1.jar:7.5.27.Final-redhat-1]
        at 
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:231)
 [jbossweb-7.5.27.Final-redhat-1.jar:7.5.27.Final-redhat-1]
        at 
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:149)
 [jbossweb-7.5.27.Final-redhat-1.jar:7.5.27.Final-redhat-1]
        at 
org.jboss.as.web.security.SubjectInfoSetupValve.invoke(SubjectInfoSetupValve.java:34)
 [jboss-as-web-7.5.19.Final-redhat-2.jar:7.5.19.Final-redhat-2]
        at 
org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:169)
 [jboss-as-web-7.5.19.Final-redhat-2.jar:7.5.19.Final-redhat-2]
        at 
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:151) 
[jbossweb-7.5.27.Final-redhat-1.jar:7.5.27.Final-redhat-1]
        at 
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:97) 
[jbossweb-7.5.27.Final-redhat-1.jar:7.5.27.Final-redhat-1]
        at 
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:102)
 [jbossweb-7.5.27.Final-redhat-1.jar:7.5.27.Final-redhat-1]
        at 
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) 
[jbossweb-7.5.27.Final-redhat-1.jar:7.5.27.Final-redhat-1]
        at 
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856) 
[jbossweb-7.5.27.Final-redhat-1.jar:7.5.27.Final-redhat-1]
        at 
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:656)
 [jbossweb-7.5.27.Final-redhat-1.jar:7.5.27.Final-redhat-1]
        at 
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:926) 
[jbossweb-7.5.27.Final-redhat-1.jar:7.5.27.Final-redhat-1]
        at java.lang.Thread.run(Thread.java:748) [rt.jar:1.8.0_191]

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