Jaxb Marshalling Xmpp Stanzas

JAXB marshalling XMPP stanzas

How about the following?:

Create a custom XMLStreamWriter that will treat all namespace declarations as default namespaces, and then marshal to that:

ByteArrayOutputStream baos = new ByteArrayOutputStream();
XMLOutputFactory xof = XMLOutputFactory.newFactory();
XMLStreamWriter xsw = xof.createXMLStreamWriter(System.out);
xsw = new MyXMLStreamWriter(xsw);
m.marshal(iq, xsw);
xsw.close();

MyXMLStreamWriter

import java.util.Iterator;

import javax.xml.namespace.NamespaceContext;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;

public class MyXMLStreamWriter implements XMLStreamWriter {

    private XMLStreamWriter xsw;
    private MyNamespaceContext nc = new MyNamespaceContext();

    public MyXMLStreamWriter(XMLStreamWriter xsw) throws Exception {
        this.xsw = xsw;
        xsw.setNamespaceContext(nc);
    }

    public void close() throws XMLStreamException {
        xsw.close();
    }

    public void flush() throws XMLStreamException {
        xsw.flush();
    }

    public NamespaceContext getNamespaceContext() {
        return xsw.getNamespaceContext();
    }

    public String getPrefix(String arg0) throws XMLStreamException {
        return xsw.getPrefix(arg0);
    }

    public Object getProperty(String arg0) throws IllegalArgumentException {
        return xsw.getProperty(arg0);
    }

    public void setDefaultNamespace(String arg0) throws XMLStreamException {
        xsw.setDefaultNamespace(arg0);
    }

    public void setNamespaceContext(NamespaceContext arg0) throws XMLStreamException {
    }

    public void setPrefix(String arg0, String arg1) throws XMLStreamException {
        xsw.setPrefix(arg0, arg1);
    }

    public void writeAttribute(String arg0, String arg1) throws XMLStreamException {
        xsw.writeAttribute(arg0, arg1);
    }

    public void writeAttribute(String arg0, String arg1, String arg2) throws XMLStreamException {
        xsw.writeAttribute(arg0, arg1, arg2);
    }

    public void writeAttribute(String arg0, String arg1, String arg2, String arg3) throws XMLStreamException {
        xsw.writeAttribute(arg0, arg1, arg2, arg3);
    }

    public void writeCData(String arg0) throws XMLStreamException {
        xsw.writeCData(arg0);
    }

    public void writeCharacters(String arg0) throws XMLStreamException {
        xsw.writeCharacters(arg0);
    }

    public void writeCharacters(char[] arg0, int arg1, int arg2) throws XMLStreamException {
        xsw.writeCharacters(arg0, arg1, arg2);
    }

    public void writeComment(String arg0) throws XMLStreamException {
        xsw.writeComment(arg0);
    }

    public void writeDTD(String arg0) throws XMLStreamException {
        xsw.writeDTD(arg0);
    }

    public void writeDefaultNamespace(String arg0) throws XMLStreamException {
        xsw.writeDefaultNamespace(arg0);
    }

    public void writeEmptyElement(String arg0) throws XMLStreamException {
        xsw.writeEmptyElement(arg0);
    }

    public void writeEmptyElement(String arg0, String arg1) throws XMLStreamException {
        xsw.writeEmptyElement(arg0, arg1);
    }

    public void writeEmptyElement(String arg0, String arg1, String arg2) throws XMLStreamException {
        xsw.writeEmptyElement(arg0, arg1, arg2);
    }

    public void writeEndDocument() throws XMLStreamException {
        xsw.writeEndDocument();
    }

    public void writeEndElement() throws XMLStreamException {
        xsw.writeEndElement();
    }

    public void writeEntityRef(String arg0) throws XMLStreamException {
        xsw.writeEntityRef(arg0);
    }

    public void writeNamespace(String arg0, String arg1) throws XMLStreamException {
    }

    public void writeProcessingInstruction(String arg0) throws XMLStreamException {
        xsw.writeProcessingInstruction(arg0);
    }

    public void writeProcessingInstruction(String arg0, String arg1) throws XMLStreamException {
        xsw.writeProcessingInstruction(arg0, arg1);
    }

    public void writeStartDocument() throws XMLStreamException {
        xsw.writeStartDocument();
    }

    public void writeStartDocument(String arg0) throws XMLStreamException {
        xsw.writeStartDocument(arg0);
    }

    public void writeStartDocument(String arg0, String arg1) throws XMLStreamException {
        xsw.writeStartDocument(arg0, arg1);
    }

    public void writeStartElement(String arg0) throws XMLStreamException {
        xsw.writeStartElement(arg0);
    }

    public void writeStartElement(String arg0, String arg1) throws XMLStreamException {
        xsw.writeStartElement(arg0, arg1);
    }

    public void writeStartElement(String arg0, String arg1, String arg2) throws XMLStreamException {
        xsw.writeStartElement("", arg1, arg2);
        if(null != arg2 || arg2.length() > 0) {
            String currentDefaultNS = nc.getNamespaceURI("");
            if(!arg2.equals(currentDefaultNS)) {
                writeDefaultNamespace(arg2);
                nc.setDefaultNS(arg2);
            }
        }
     }

    private static class MyNamespaceContext implements NamespaceContext {

        private String defaultNS = "";

        public void setDefaultNS(String ns) {
            defaultNS = ns;
        }

        public String getNamespaceURI(String arg0) {
            if("".equals(arg0)) {
                return defaultNS;
            }
            return null;
        }

        public String getPrefix(String arg0) {
            return "";
        }

        public Iterator getPrefixes(String arg0) {
            return null;
        }

    }
}

JAXB marshalling: change element which should declare a namespace

JAXB (JSR-222) does not provide a means to control where namespace declarations occur. JAXB providers tend to put the namespaces on the root element (for performance reasons), but they are not required to.

Below is a link to an answer I gave to a similar question where XMLStreamWriter is extended to control when the namespace declarations get reported.

• JAXB marshalling XMPP stanzas

Receive custom XMPP stanzas with Smack

If you use PacketExtension to send custom stanzas, as this thread explained: https://stackoverflow.com/a/6390037/474002

Then, you could use smack api Packet.getExtensions as the document: http://www.igniterealtime.org/builds/smack/docs/latest/javadoc/org/jivesoftware/smack/packet/Packet.html#getExtensions()

Hope this will help ~

XSD from XML Java Jaxb

This is xxx.xsd, defining the outer element in the foo namespace:

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
        xmlns:jaxb="http://java.sun.com/xml/ns/jaxb"
        xmlns:foo="http://foo.com"
        targetNamespace="http://foo.com"
        xmlns:bar="http://bar.com"
        jaxb:version="2.0">
  <xsd:import namespace="http://bar.com" 
              schemaLocation="yyy.xsd"/>
  <xsd:complexType name="DataType">
    <xsd:sequence>
      <xsd:element ref="bar:childData"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:element name="data" type="foo:DataType"/>
</xsd:schema>

And here is yyy.xsd:

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            xmlns:jaxb="http://java.sun.com/xml/ns/jaxb"
            targetNamespace="http://bar.com"
            xmlns:bar="http://bar.com"
            jaxb:version="2.0">
  <xsd:element name="childData" type="xsd:string"/>
</xsd:schema>

Later The usual Java code for marshalling:

 void marshal() throws Exception {
    JAXBContext jc = JAXBContext.newInstance( "com.foo:com.bar" );
    Marshaller m = jc.createMarshaller();
    DataType data = new DataType();
    ObjectFactory of = new ObjectFactory();
    JAXBElement<DataType> jbe = of.createData(data);
    data.setChildData("child data");
    m.marshal( jbe, System.out );
}

produces

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns2:data xmlns="http://bar.com" xmlns:ns2="http://foo.com">  
  <childData>child data</childData>
</ns2:data>

which is equivalent to the XML you have posted.

XML Marshalling: I want namespace attributes and not prefixes

You can try using NamespacePrefixMapper. You have to extend it and set it as a property.

Here's an example of the shortest method:

marshaller.setProperty("com.sun.xml.bind.namespacePrefixMapper", 
                                              new NamespacePrefixMapper() {

            @Override
            public String[] getPreDeclaredNamespaceUris() {
                return new String[] { MyNamespaces.EXAMPLE_MAIN };
            }

            @Override
            public String getPreferredPrefix(String namespaceUri, String suggestion, boolean requirePrefix) {
                if (namespaceUri.equals(MyNamespaces.EXAMPLE_MAIN) ||
                    namespaceUri.equals(MyNamespaces.EXAMPLE_MAIN_RULE))

                    return "";

            }
        }); 

Embedding XML document inside another XML with JAXB

Thanks to Blaise for mention his previous answer. I ended using a similar approach:

This is how I intercepted the Writer:

StringWriter writer = new StringWriter();
XMLOutputFactory factory = XMLOutputFactory.newFactory();
XMLWriter xmlWriter = new XMLWriter(factory.createXMLStreamWriter(writer));
marshaller.marshal(message, xmlWriter);

And here is the XMLWriter class:

import java.util.Iterator;

import javax.xml.namespace.NamespaceContext;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;

public class XMLWriter implements XMLStreamWriter {

private XMLStreamWriter writer;

private ProxyNameSpaceContext nc = new ProxyNameSpaceContext();

public XMLWriter(XMLStreamWriter writer) throws XMLStreamException {
    super();
    this.writer = writer;
    writer.setNamespaceContext(nc);
}

@Override
public void close() throws XMLStreamException {
    writer.close();
}

@Override
public void flush() throws XMLStreamException {
    writer.flush();
}

@Override
public NamespaceContext getNamespaceContext() {
    return writer.getNamespaceContext();
}

@Override
public String getPrefix(String uri) throws XMLStreamException {
    return writer.getPrefix(uri);
}

@Override
public Object getProperty(String name) throws IllegalArgumentException {
    return writer.getProperty(name);
}

@Override
public void setDefaultNamespace(String uri) throws XMLStreamException {
    writer.setDefaultNamespace(uri);
}

@Override
public void setNamespaceContext(NamespaceContext context)
        throws XMLStreamException {
}

@Override
public void setPrefix(String prefix, String uri) throws XMLStreamException {
    writer.setPrefix(prefix, uri);
}

@Override
public void writeAttribute(String prefix, String namespaceURI,
        String localName, String value) throws XMLStreamException {
    writer.writeAttribute(prefix, namespaceURI, localName, value);
}

@Override
public void writeAttribute(String namespaceURI, String localName,
        String value) throws XMLStreamException {
    writer.writeAttribute(namespaceURI, localName, value);
}

@Override
public void writeAttribute(String localName, String value)
        throws XMLStreamException {
    writer.writeAttribute(localName, value);
}

@Override
public void writeCData(String data) throws XMLStreamException {
    writer.writeCData(data);
}

@Override
public void writeCharacters(char[] text, int start, int len)
        throws XMLStreamException {
    writer.writeCharacters(text, start, len);
}

@Override
public void writeCharacters(String text) throws XMLStreamException {
    writer.writeCharacters(text);
}

@Override
public void writeComment(String data) throws XMLStreamException {
    writer.writeComment(data);
}

@Override
public void writeDTD(String dtd) throws XMLStreamException {
    writer.writeDTD(dtd);
}

@Override
public void writeDefaultNamespace(String namespaceURI)
        throws XMLStreamException {
    writer.writeDefaultNamespace(namespaceURI);
}

@Override
public void writeEmptyElement(String prefix, String localName,
        String namespaceURI) throws XMLStreamException {
    writer.writeEmptyElement(prefix, localName, namespaceURI);
}

@Override
public void writeEmptyElement(String namespaceURI, String localName)
        throws XMLStreamException {
    writer.writeEmptyElement(namespaceURI, localName);
}

@Override
public void writeEmptyElement(String localName) throws XMLStreamException {
    writer.writeEmptyElement(localName);
}

@Override
public void writeEndDocument() throws XMLStreamException {
    writer.writeEndDocument();
}

@Override
public void writeEndElement() throws XMLStreamException {
    writer.writeEndElement();
}

@Override
public void writeEntityRef(String name) throws XMLStreamException {
    writer.writeEntityRef(name);
}

@Override
public void writeNamespace(String prefix, String namespaceURI)
        throws XMLStreamException {
    writer.writeNamespace(prefix, namespaceURI);
}

@Override
public void writeProcessingInstruction(String target, String data)
        throws XMLStreamException {
    writer.writeProcessingInstruction(target, data);
}

@Override
public void writeProcessingInstruction(String target)
        throws XMLStreamException {
    writer.writeProcessingInstruction(target);
}

@Override
public void writeStartDocument() throws XMLStreamException {
    writer.writeStartDocument();
}

@Override
public void writeStartDocument(String encoding, String version)
        throws XMLStreamException {
    writer.writeStartDocument(encoding, version);
}

@Override
public void writeStartDocument(String version) throws XMLStreamException {
    writer.writeStartDocument(version);
}

@Override
public void writeStartElement(String prefix, String localName,
        String namespaceURI) throws XMLStreamException {
    writer.writeStartElement("", localName, namespaceURI);
    if(null != namespaceURI && namespaceURI.length() > 0) {
        String currentDefaultNS = nc.getNamespaceURI("");
        if(!namespaceURI.equals(currentDefaultNS)) {
            writeDefaultNamespace(namespaceURI);
            nc.setDefaultNS(namespaceURI);
        }
    }
}

@Override
public void writeStartElement(String namespaceURI, String localName)
        throws XMLStreamException {
    writer.writeStartElement(namespaceURI, localName);
}

@Override
public void writeStartElement(String localName) throws XMLStreamException {
    writer.writeStartElement(localName);
}

public static class ProxyNameSpaceContext implements NamespaceContext {

    private String defaultNS = "";

    public void setDefaultNS(String ns) {
        defaultNS = ns;
    }

    @Override
    public String getNamespaceURI(String prefix) {
        if("".equals(prefix)) {
            return defaultNS;
        }
        return null;
    }

    @Override
    public String getPrefix(String namespaceURI) {
        return "";
    }

    @Override
    public Iterator<?> getPrefixes(String namespaceURI) {
        return null;
    }

}

}

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