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Asked: 2026-05-23T01:10:40+00:00

I wrote a xml parser with StAx that I use to parse XML streams

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I wrote a xml parser with StAx that I use to parse XML streams received from the server.Here is my code : 

private Map<String, IUnitaryAction> parse(InputStream is) throws XMLStreamException {

    XMLInputFactory factory = XMLInputFactory.newInstance();
    XMLStreamReader reader = factory.createXMLStreamReader(is);
    boolean action = false;
    Map<String, IUnitaryAction> actionsMap = new HashMap<String, IUnitaryAction>();

    while(reader.hasNext()){
        int type = reader.next();
        switch(type){
        case XMLStreamReader.START_ELEMENT :
            action = reader.getLocalName().equals("action-description");
            break;

        case XMLStreamReader.CHARACTERS :
            if( action ){
                String act = reader.getText();
                System.out.println("Action trouvées " + act);

                String[] praxiscmd = act.split("_");
                if("CREATE".equals(praxiscmd[0])){
                    Create c = new Create(praxiscmd[1], praxiscmd[2], null);
                    actionsMap.put(praxiscmd[1], c);
                } else if("DELETE".equals(praxiscmd[0])){
                    Delete d = new Delete(praxiscmd[1],praxiscmd[2], null);
                    actionsMap.put(praxiscmd[1], d);
                } else if ("ADDPROPERTY".equals(praxiscmd[0])) {
                    AddProperty ap = new AddProperty(praxiscmd[1],
                            praxiscmd[2], praxiscmd[3], null);
                    actionsMap.put(praxiscmd[1], ap);
                } else if ("ADDREFERENCE".equals(praxiscmd[0])) {
                    AddReference ar = new AddReference(praxiscmd[1],
                            praxiscmd[2], praxiscmd[3], null);
                    actionsMap.put(praxiscmd[1], ar);
                } else if ("REMPROPERTY".equals(praxiscmd[0])) {
                    RemProperty rp = new RemProperty(praxiscmd[1],
                            praxiscmd[2], praxiscmd[3], null);
                    actionsMap.put(praxiscmd[1], rp);
                } else if ("REMREFERENCE".equals(praxiscmd[0])) {
                    RemReference rr = new RemReference(praxiscmd[1],
                            praxiscmd[2], praxiscmd[3], null);
                    actionsMap.put(praxiscmd[1], rr);
                }
            }
        }
    }

I get this error on the line : int type = reader.next(): 

 javax.xml.stream.XMLStreamException: ParseError at [row,col]:[1,1]
Message: Premature end of file.
    at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(XMLStreamReaderImpl.java:584)
    at fr.lip6.graphelex.TelexImpl.parse(TelexImpl.java:147)
    at fr.lip6.graphelex.TelexImpl.sendHttpRequest(TelexImpl.java:264)
    at fr.lip6.graphelex.TelexImpl.schedules(TelexImpl.java:116)
    at fr.lip6.graphelex.MapperImpl.send(MapperImpl.java:92)
    at fr.lip6.graphelex.GraphElexAgent.executeCycle(GraphElexAgent.java:81)
    at praxis.guidance.agent.Agent.run(Agent.java:71)
    at java.lang.Thread.run(Thread.java:636)

I don’t understand what is the problem since i use the same parser for another case and it perfectly work.
Here is an example of XML streams I received from a server :

  <?xml version="1.0" encoding="UTF-8" standalone="no"?>
  <responses>
   <executed-commands>
      <command><name>GETLASTSCEDULES</name>
      <status-code>200</status-code>
      <description>last schedule returned</description>
      </command>
     </executed-commands>
       <schedules><schedule><schedule-id>0</schedule-id>
       <doc-id>/telexDocuments/doc.dox</doc-id>
       <actions>
         <action>
          <action-description>CREATE__8VtAMXv4EeCwaM2v2VqUyg_Model</action-description>  
         <action-id>/telexDocuments/doc.dox:Peer#server2:hephaistos:0:15</action-id>
        </action>
      </actions>
      <non-actions/></schedule></schedules>
      <get-constraints/>
</responses>

Can someone give some advice ?

EDIT :
I may find the answer to my question. The problem was when I have received the answer from the server as InputStream, I read parse it. As you may know, in Java, once an InputStream is read parsed, it is close automatically. Things sometime we forgot. Thanks for the documentation

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1 Answer

  1. Editorial Team

    Strictly because an answer is easier to read than the reading through the comments….

    Answer from Dimitri

    I may find the answer to my question. The problem was when I have received the answer from the server as InputStream, I parse it. As you may know, in Java, once an InputStream is parsed, it is close automatically. Things sometime we forgot. Thanks for the documentation
    .

    The answer is very simple. In my program, before I called the method I parse, I use to display the content input Stream to see what I am receiving. The fact is, once you read/parse your inpustream, it is automatically close. See the link below. So when I call my method parse, the Inputstream parameter was already close, this is why I caught this error.

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