/jWebSocket/libs/J2SE/Javolution/src/javolution/xml/ws/WebServiceClient.java

/*

 * Javolution - Java(TM) Solution for Real-Time and Embedded Systems

 * Copyright (C) 2007 - Javolution (http://javolution.org/)

 * All rights reserved.

 * 

 * Permission to use, copy, modify, and distribute this software is

 * freely granted, provided that this notice is preserved.

 */

package javolution.xml.ws;



import java.io.IOException;



import java.lang.CharSequence;

import java.lang.UnsupportedOperationException;

import javolution.io.AppendableWriter;

import javolution.io.UTF8StreamWriter;

import javolution.text.Text;

import javolution.text.TextBuilder;

import javolution.xml.XMLObjectReader;

import javolution.xml.XMLObjectWriter;

import javolution.xml.stream.XMLStreamException;

import javolution.xml.stream.XMLStreamReader;

import javolution.xml.stream.XMLStreamWriter;



/**

 * <p> This class provides a simple web service client capable of leveraging  

 *     Javolution {@link javolution.xml XML marshalling/unmarshalling}.</p>

 *     

 * <p> Sub-classes may work from WSDL files, {@link javolution.xml.XMLFormat

 *     XMLFormat} or directly with the XML streams (StAX). For example:[code]

 *     private static class HelloWorld extends WebServiceClient  {

 *         protected void writeRequest(XMLObjectWriter out) throws XMLStreamException {

 *             XMLStreamWriter xml = out.getStreamWriter();

 *             xml.writeDefaultNamespace("http://www.openuri.org/");

 *             xml.writeEmptyElement("helloWorld"); // Operation name.

 *         }

 *         protected void readResponse(XMLObjectReader in) throws XMLStreamException {

 *             XMLStreamReader xml = in.getStreamReader();

 *             xml.require(START_ELEMENT, "http://www.openuri.org/", "string");

 *             xml.next(); // Move to character content.

 *             System.out.println(xml.getText());

 *         }

 *     }

 *     WebServiceClient ws = new HelloWorld().setAddress("http://acme.com:80/HelloWorld.jws");

 *     ws.invoke();

 *     

 *      > Hello World!

 *     [/code]</p>

 *     

 * <p><b>Note:</b> At this moment, this class is supported only on the J2SE 

 *                 platform. Soon, it will also be supported on mobile devices

 *                 through the CLDC/MIDP Generic Connection framework.</p>

 *           

 * @author  <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a>

 * @version 5.2, September 16, 2007

 */

public abstract class WebServiceClient {



    /**

     * Holds standard SOAP envelope prefix.

     */

    public static final String ENVELOPE_PREFIX = "env";



    /**

     * Holds standard SOAP envelope namespace.

     */

    public static final String ENVELOPE_URI = "http://schemas.xmlsoap.org/soap/envelope/";



    /**

     * Holds the URL (J2SE).

     */

    Object _url;



    /**

     * Default constructor (address not set).

     */

    public WebServiceClient() {

        /**/

        if (true) return;

        /**/

        throw new UnsupportedOperationException("J2ME Not Supported Yet");

    }



    /**

     * Sets the address of this web service.

     * 

     * @param address the service full address. 

     */

    public WebServiceClient setAddress(String address) {

        /**/    

        try {

            _url = new java.net.URL(address);

        } catch (java.net.MalformedURLException e) {

            throw new IllegalArgumentException("Malformed URL: " + address);

        }

        /**/

        return this;

    }



    /**

     * Invokes the web service.

     */

    public void invoke() throws IOException, XMLStreamException {

        try {

            // Formats the request message (we cannot write directly to 

            // the output stream because the http request requires the length.

            _out.setOutput(_buffer);

            _writer.setOutput(_out);

            final XMLStreamWriter xmlOut = _writer.getStreamWriter();

            xmlOut.setPrefix(csq(ENVELOPE_PREFIX), csq(ENVELOPE_URI));

            xmlOut.writeStartElement(csq(ENVELOPE_URI), csq("Envelope"));

            xmlOut.writeNamespace(csq(ENVELOPE_PREFIX), csq(ENVELOPE_URI));

            xmlOut.writeStartElement(csq(ENVELOPE_URI), csq("Header"));

            xmlOut.writeEndElement();

            xmlOut.writeStartElement(csq(ENVELOPE_URI), csq("Body"));

            writeRequest(_writer);

            _writer.close();



            // Sends the request.

            if (_url == null)

                throw new IOException("URL not set");

            /**/    

            java.net.HttpURLConnection http = (java.net.HttpURLConnection) 

               ((java.net.URL)_url).openConnection();

            http.setRequestProperty("Content-Length", String.valueOf(_buffer

                    .length()));

            http.setRequestProperty("Content-Type", "text/xml; charset=utf-8");

            // httpConn.setRequestProperty("SOAPAction", "");

            http.setRequestMethod("POST");

            http.setDoOutput(true);

            http.setDoInput(true);

            _utf8Writer.setOutput(http.getOutputStream());

            /**/

            _buffer.print(_utf8Writer);

            _utf8Writer.close();



            // Reads the response.

            /**/    

            _reader.setInput(http.getInputStream());

            /**/

            final XMLStreamReader xmlIn = _reader.getStreamReader();

            while (xmlIn.hasNext()) {

                if ((xmlIn.next() == XMLStreamReader.START_ELEMENT)

                        && xmlIn.getLocalName().equals("Body")

                        && xmlIn.getNamespaceURI().equals(ENVELOPE_URI)) {

                    // Found body, position reader to next element.

                    xmlIn.next();

                    readResponse(_reader);

                    break;

                }

            }



        } finally {

            _reader.close();

            _writer.reset();

            _out.reset();

            _buffer.reset();

            _utf8Writer.reset();

            _reader.reset();

        }

    }

    private final TextBuilder _buffer = new TextBuilder();

    private final AppendableWriter _out = new AppendableWriter();

    private final XMLObjectWriter _writer = new XMLObjectWriter();

    private final UTF8StreamWriter _utf8Writer = new UTF8StreamWriter();

    private  final XMLObjectReader _reader = new XMLObjectReader();

    /**/

    

    /**

     * Writes the web service request (SOAP body).

     * 

     * @param out the XML object writer.

     */

    protected abstract void writeRequest(XMLObjectWriter out)

            throws XMLStreamException;



    /**

     * Reads the web service response (SOAP body). The default implementation

     * writes the body XML events to <code>System.out</code>.

     * 

     * @param in the XML object reader.

     */

    protected void readResponse(XMLObjectReader in) throws XMLStreamException {

        final XMLStreamReader xml = in.getStreamReader();

        while (xml.hasNext()) {

            switch (xml.next()) {

            case XMLStreamReader.START_DOCUMENT:

                System.out.println("Start Document");

                break;

            case XMLStreamReader.END_DOCUMENT:

                System.out.println("End Document.");

                break;

            case XMLStreamReader.START_ELEMENT:

                System.out.println("Start Element: " + xml.getLocalName() + "("

                        + xml.getNamespaceURI() + ")");

                for (int i = 0, n = xml.getAttributeCount(); i < n; i++) {

                    System.out.println("   Attribute: "

                            + xml.getAttributeLocalName(i) + "("

                            + xml.getAttributeNamespace(i) + "), Value: "

                            + xml.getAttributeValue(i));

                }

                break;

            case XMLStreamReader.END_ELEMENT:

                if (xml.getLocalName().equals("Body")

                        && xml.getNamespaceURI().equals(ENVELOPE_URI))

                    return; // End body.

                System.out.println("End Element: " + xml.getLocalName() + "("

                        + xml.getNamespaceURI() + ")");

                break;

            case XMLStreamReader.CHARACTERS:

                System.out.println("Characters: " + xml.getText());

                break;

            case XMLStreamReader.CDATA:

                System.out.println("CDATA: " + xml.getText());

                break;

            case XMLStreamReader.COMMENT:

                System.out.println("Comment: " + xml.getText());

                break;

            case XMLStreamReader.SPACE:

                System.out.println("Space");

                break;

            default:

                System.out.println(xml);

            }

        }



    }  

    

    // For J2ME compatiblity.

    private static final CharSequence csq(Object string) {

        return (string instanceof CharSequence) ? (CharSequence) string:

            Text.valueOf(string);

        

    }

}