httpposter.java

J2ME MIDP_Example_Applications

// Copyright 2003 Nokia Corporation.
//
// THIS SOURCE CODE IS PROVIDED 'AS IS', WITH NO WARRANTIES WHATSOEVER,
// EXPRESS OR IMPLIED, INCLUDING ANY WARRANTY OF MERCHANTABILITY, FITNESS
// FOR ANY PARTICULAR PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE
// OR TRADE PRACTICE, RELATING TO THE SOURCE CODE OR ANY WARRANTY OTHERWISE
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// SUPPORT. FURTHERMORE, NOKIA MAKES NO WARRANTY THAT EXERCISE OF THE
// RIGHTS GRANTED HEREUNDER DOES NOT INFRINGE OR MAY NOT CAUSE INFRINGEMENT
// OF ANY PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OWNED OR CONTROLLED
// BY THIRD PARTIES
//
// Furthermore, information provided in this source code is preliminary,
// and may be changed substantially prior to final release. Nokia Corporation
// retains the right to make changes to this source code at
// any time, without notice. This source code is provided for informational
// purposes only.
//
// Nokia and Nokia Connecting People are registered trademarks of Nokia
// Corporation.
// Java and all Java-based marks are trademarks or registered trademarks of
// Sun Microsystems, Inc.
// Other product and company names mentioned herein may be trademarks or
// trade names of their respective owners.
//
// A non-exclusive, non-transferable, worldwide, limited license is hereby
// granted to the Licensee to download, print, reproduce and modify the
// source code. The licensee has the right to market, sell, distribute and
// make available the source code in original or modified form only when
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// intellectual property rights is granted herein.


import java.io.*;
import java.util.*;
import javax.microedition.io.*;


// This class accepts and queues POST requests for a particular URL, and
// services them in first-in-first-out order. Using the queue allows
// it to be thread-safe without forcing its clients ever to block.


class HttpPoster
    implements Runnable
{
    private String url;
    private volatile boolean aborting = false;
    private Vector requestQueue = new Vector();
    private Vector httpRequestPropertiesQueue = new Vector();
    private Vector listenerQueue = new Vector();


    HttpPoster(String url)
    {
        this.url = url;

        Thread thread = new Thread(this);
        thread.start();
    }


    synchronized void sendHttpRequest(byte[] bytes,
                                      Hashtable httpRequestProperties,
                                      HttpPosterListener listener)
        throws IOException, UnsupportedEncodingException
    {
        httpRequestPropertiesQueue.addElement(httpRequestProperties);

        requestQueue.addElement(bytes);

        listenerQueue.addElement(listener);

        notify(); // wake up sending thread
    }



    public void run()
    {
        running :
        while (!aborting)
        {
            Hashtable httpRequestProperties;
            HttpPosterListener listener;

            byte[] bytes = null;
            synchronized (this)
            {
                while (requestQueue.size() == 0)
                {
                    try
                    {
                        wait(); // releases lock
                    }
                    catch (InterruptedException e)
                    {
                    }

                    if (aborting)
                    {
                        break running;
                    }
                }

                httpRequestProperties =
                    (Hashtable)
                    (httpRequestPropertiesQueue.elementAt(0));
                bytes = (byte[]) requestQueue.elementAt(0);
                listener = (HttpPosterListener)
                           (listenerQueue.elementAt(0));
                httpRequestPropertiesQueue.removeElementAt(0);
                requestQueue.removeElementAt(0);
                listenerQueue.removeElementAt(0);
            }

            // sendHttpRequest must have notified us
            doSend(httpRequestProperties, bytes, listener);
        }
    }


    private void doSend(Hashtable httpRequestProperties,
                        byte[] bytes,
                        HttpPosterListener listener)
    {
        HttpConnection conn = null;
        InputStream in = null;
        OutputStream out = null;
        String responseStr = null;
        String errorStr = null;
        boolean wasError = false;

        ByteArrayOutputStream responseBytes =
            new ByteArrayOutputStream();
        try
        {
            conn = (HttpConnection) Connector.open(url);

            // Set the request method
            conn.setRequestMethod(HttpConnection.POST);

            // Set the HTTP request header fields
            Enumeration enumeration = httpRequestProperties.keys();
            while(enumeration.hasMoreElements())
            {
            	String name = (String) enumeration.nextElement();
                String value = (String) httpRequestProperties.get(name);
            	conn.setRequestProperty(name, value);
            }

            // Getting the output stream may flush the headers
            out = conn.openOutputStream();

            out.write(bytes);

            // Opening the InputStream will open the connection
            // and read the HTTP headers. They are stored
            // until requested.
            in = conn.openInputStream();

            // Get the length and process the data
            int ch;
            while ((ch = in.read()) != -1)
            {
                responseBytes.write(ch);
            }

            // If needed, one could add support for HTTP sessions
            // using URL re-writing here. See the SumMIDlet example
            // for more details.
        }
        catch (IOException e)
        {
            wasError = true;

            errorStr = "IOException connecting to '" + url + "'";
            if (e.getMessage() != null)
            {
                errorStr += (": " + e.getMessage());
            }
        }
        catch (SecurityException e)
        {
            wasError = true;
            errorStr = e.getMessage();
        }
        finally
        {
            if (in != null)
            {
                try
                {
                    in.close();
                }
                catch (IOException e)
                {
                    // just ignore, there is nothing we can do
                }
            }
            if (out != null)
            {
                try
                {
                    out.close();
                }
                catch (IOException e)
                {
                    // just ignore, there is nothing we can do
                }
            }
            if (conn != null)
            {
                try
                {
                    conn.close();
                }
                catch (IOException e)
                {
                    // just ignore, there is nothing we can do
                }
            }
        }


        if (wasError)
        {
            listener.handleHttpPosterError(errorStr);
        }
        else
        {
            listener.receiveHttpResponse(responseBytes.toByteArray());
        }
    }


    // The instance is useless after abort has been called.
    void abort()
    {
        aborting = true;
        synchronized (this)
        {
            notify(); // wake up our posting thread and kill it
        }
    }


    boolean isAborting()
    {
        return aborting;
    }
}