Academic Tutorials



English | French | Portugese | German | Italian
Home Advertise Payments Recommended Websites Interview Questions FAQs
News Source Codes E-Books Downloads Jobs Web Hosting
Chats

J2ME
Introduction to J2ME
J2ME Development Kit
Understanding the Process of MIDlet
The MIDlet Lifecycle
User Interface Architecture
Alert
List
Text Box
Form
Images, Tickers and Gauges
Handling User Commands
Working with the Low-Level API
J2ME Gaming API
A Very Short Primer on Game Building
Building a J2ME Game
Defining Game Characteristics
TiledLayer
Sprites and LayerManager
Managing Layers
Sprites and Detecting Collisions
Mobile Media API
Using Mobile Media API (MMAPI)
Streaming media over the network

HTML Tutorials
HTML Tutorial
XHTML Tutorial
CSS Tutorial
TCP/IP Tutorial
CSS 1.0
CSS 2.0
HLML
XML Tutorials
XML Tutorial
XSL Tutorial
XSLT Tutorial
DTD Tutorial
Schema Tutorial
XForms Tutorial
XSL-FO Tutorial
XML DOM Tutorial
XLink Tutorial
XQuery Tutorial
XPath Tutorial
XPointer Tutorial
RDF Tutorial
SOAP Tutorial
WSDL Tutorial
RSS Tutorial
WAP Tutorial
Web Services Tutorial
Browser Scripting
JavaScript Tutorial
VBScript Tutorial
DHTML Tutorial
HTML DOM Tutorial
WMLScript Tutorial
E4X Tutorial
Server Scripting
ASP Tutorial
PERL Tutorial
SQL Tutorial
ADO Tutorial
CVS
Python
Apple Script
PL/SQL Tutorial
SQL Server
PHP
.NET (dotnet)
Microsoft.Net
ASP.Net
.Net Mobile
C# : C Sharp
ADO.NET
VB.NET
VC++
Multimedia
SVG Tutorial
Flash Tutorial
Media Tutorial
SMIL Tutorial
Photoshop Tutorial
Gimp Tutorial
Matlab
Gnuplot Programming
GIF Animation Tutorial
Scientific Visualization Tutorial
Graphics
Web Building
Web Browsers
Web Hosting
W3C Tutorial
Web Building
Web Quality
Web Semantic
Web Careers
Weblogic Tutorial
SEO
Web Site Hosting
Domain Name
Java Tutorials
Java Tutorial
JSP Tutorial
Servlets Tutorial
Struts Tutorial
EJB Tutorial
JMS Tutorial
JMX Tutorial
Eclipse
J2ME
JBOSS
Programming Langauges
C Tutorial
C++ Tutorial
Visual Basic Tutorial
Data Structures Using C
Cobol
Assembly Language
Mainframe
Forth Programming
Lisp Programming
Pascal
Delphi
Fortran
OOPs
Data Warehousing
CGI Programming
Emacs Tutorial
Gnome
ILU
Soft Skills
Communication Skills
Time Management
Project Management
Team Work
Leadership Skills
Corporate Communication
Negotiation Skills
Database Tutorials
Oracle
MySQL
Operating System
BSD
Symbian
Unix
Internet
IP-Masquerading
IPC
MIDI
Software Testing
Testing
Firewalls
SAP Module
ERP
ABAP
Business Warehousing
SAP Basis
Material Management
Sales & Distribution
Human Resource
Netweaver
Customer Relationship Management
Production and Planning
Networking Programming
Corba Tutorial
Networking Tutorial
Microsoft Office
Microsoft Word
Microsoft Outlook
Microsoft PowerPoint
Microsoft Publisher
Microsoft Excel
Microsoft Front Page
Microsoft InfoPath
Microsoft Access
Accounting
Financial Accounting
Managerial Accounting
Network Sites


Streaming media over the network


Previoushome






Streaming media over the network

It is highly likely that the media files, especially video files, will not be distributed with your MIDlet, unless they are really small in size. For a successful MIDlet application, the ability to stream media over the network is essential. MediaMIDlet can play media over the network easily by specifying an HTTP based file. However, there are two issues to be considered in such a case.


A D V E R T I S E M E N T

First, media access over the network requires explicit permission from the end user. After all, this network usage will likely incur a cost to the user, which he must agree to. There are ways to ask this permission once and store the result within the MIDlet environment, but I will not go into too much detail over here. For the moment, it is sufficient to be aware of this issue.

Second, media access over the network can be a time consuming operation. This operation should not be done in the main application thread, in case it ties it up in an intermittent network and blocks forever. All network access should be done in a separate thread.

Keeping these two issues in mind, Listing 2 shows a modified version of Listing 1 (and the code that was added to it to play video files). The first issue is taken care of by the underlying Application Management Software (AMS). It explicitly asks for user permission once network access is required. The second issue is taken care of by separating the network media access code in its own thread.

package com.j2me.part4;

import java.util.Hashtable;
import java.util.Enumeration;

import javax.microedition.lcdui.Item;
import javax.microedition.lcdui.List;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.Alert;
import javax.microedition.midlet.MIDlet;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.CommandListener;

import javax.microedition.media.Player;
import javax.microedition.media.Control;
import javax.microedition.media.Manager;
import javax.microedition.media.PlayerListener;
import javax.microedition.media.control.VideoControl;

public class MediaMIDletV2 extends MIDlet
  implements CommandListener {

  private Display display;
  private List itemList;
  private Form form;

  private Hashtable items;

  public MediaMIDletV2() {

    display = Display.getDisplay(this);

    // creates an item list to let you select multimedia files to play
    itemList = new List("Select an item to play", List.IMPLICIT);


    // a form to display when items are being played
    form = new Form("Playing media");

    // create a hashtable of items
    items = new Hashtable();

    // and populate both of them
    items.put("Siren from web", "http://www.craftbits.com/j2me/siren.wav");
    items.put(
      "Promo Video from web",
      "http://www.craftbits.com/j2me/promo.mpg");
  }

  public void startApp() {

    // when MIDlet is started, use the item list to display elements
    for(Enumeration en = items.keys(); en.hasMoreElements();) {
      itemList.append((String)en.nextElement(), null);
    }

    itemList.setCommandListener(this);

    // show the list when MIDlet is started
    display.setCurrent(itemList);
  }

  public void pauseApp() {
  }

  public void destroyApp(Boolean unconditional) {
  }


  public void commandAction(Command command, Displayable disp) {

    // generic command handler

    // if list is displayed, the user wants to play the item
    if(disp instanceof List) {
      List list = ((List)disp);

      String key = list.getString(list.getSelectedIndex());

      // try and play the selected file
      try {
        playMedia((String)items.get(key));
      } catch (Exception e) {
        System.err.println("Unable to play: " + e);
        e.printStackTrace();
      }
    }

  }


  /* Creates Player and plays media for the first time */
  private void playMedia(String locator) throws Exception {

    PlayerManager manager =
      new PlayerManager(form, itemList, locator, display);
    form.setCommandListener(manager);
    Thread runner = new Thread(manager);
    runner.start();
  }
}

class PlayerManager implements Runnable, CommandListener, PlayerListener {

  Form form;
  List list;
  Player player;
  String locator;
  Display display;

  private Command stopCommand;
  private Command pauseCommand;
  private Command startCommand;

  public PlayerManager(Form form, List list, String locator, Display display) {
  this.form = form;
  this.list = list;
  this.locator = locator;
  this.display = display;

    // stop, pause and restart commands
    stopCommand = new Command("Stop", Command.STOP, 1);
    pauseCommand = new Command("Pause", Command.ITEM, 1);
    startCommand = new Command("Start", Command.ITEM, 1);

    // the form acts as the interface to stop and pause the media
    form.addCommand(stopCommand);
    form.addCommand(pauseCommand);
  }

  public void run() {

    try {
      // since we are loading data over the network, a delay can be
      // expected
      Alert alert = new Alert("Loading. Please wait ....");
      alert.setTimeout(Alert.FOREVER);
      display.setCurrent(alert);

      player = Manager.createPlayer(locator);

      // a listener to handle player events like starting, closing etc
      player.addPlayerListener(this);

      player.setLoopCount(-1); // play indefinitely
      player.prefetch(); // prefetch
      player.realize(); // realize

      player.start(); // and start
    } catch(Exception e) {
      System.err.println(e);
      e.printStackTrace();
    }
  }

  public void commandAction(Command command, Displayable disp) {
    if(disp instanceof Form) {
      // if showing form, means the media is being played
      // and the user is trying to stop or pause the player
      try {
        if(command == stopCommand) { // if stopping the media play
          player.close(); // close the player
          display.setCurrent(list); // redisplay the list of media
          form.removeCommand(startCommand); // remove the start command
          form.removeCommand(pauseCommand); // remove the pause command
          form.removeCommand(stopCommand);  // and the stop command
        } else if(command == pauseCommand) { // if pausing
          player.stop(); // pauses the media, note that it is called stop
          form.removeCommand(pauseCommand); // remove the pause command
          form.addCommand(startCommand); // add the start (restart) command
        } else if(command == startCommand) { // if restarting
          player.start(); // starts from where the last pause was called
          form.removeCommand(startCommand);
          form.addCommand(pauseCommand);
        }
      } catch(Exception e) {
        System.err.println(e);
      }
    }
  }

  /* Handle player events */
  public void playerUpdate(Player player, String event, Object eventData) {

    // if the event is that the player has started, show the form
    // but only if the event data indicates that the event relates to newly
    // stated player, as the STARTED event is fired even if a player is
    // restarted. Note that eventData indicates the time at which the start
    // event is fired.
    if(event.equals(PlayerListener.STARTED) &&
      new Long(0L)Equals((Long)eventData)) {

      // see if we can show a video control, depending on whether the media
      // is a video or not
      VideoControl vc = null;
      if((vc = (VideoControl)player.getControl("VideoControl")) != null) {
        Item videoDisp =
          (Item)vc.initDisplayMode(vc.USE_GUI_PRIMITIVE, null);
        form.append(videoDisp);
      }

      display.setCurrent(form);
    } else if(event.equals(PlayerListener.CLOSED)) {

      form.deleteAll(); // clears the form of any previous controls
    }
  }

}

Listing 2. Media access over the network in its own thread

As you can see, all of the code that interacts with the media has been moved to the PlayerManager class, which is run in its own thread. Figure 5 shows how the interaction with the MIDlet will work now.

Figure 5
Figure 5. The process of media access over the network

Notice how the MIDlet asks for user permission to access the network before the player can be created. Permission granted once is assumed granted for the whole time the MIDlet is running; therefore, repeated network access to access other files does not bring up this screen.



Be the first one to comment on this page.




  J2ME eBooks

No eBooks on J2ME could be found as of now.

 
 J2ME FAQs
More Links » »
 
 J2ME Interview Questions
More Links » »
 
 J2ME Articles
More Links » »
 
 J2ME News
More Links » »
 
 J2ME Jobs
More Links » »

Share And Enjoy:These icons link to social bookmarking sites where readers can share and discover new web pages.
  • blinkbits
  • BlinkList
  • blogmarks
  • co.mments
  • connotea
  • del.icio.us
  • De.lirio.us
  • digg
  • Fark
  • feedmelinks
  • Furl
  • LinkaGoGo
  • Ma.gnolia
  • NewsVine
  • Netvouz
  • RawSugar
  • Reddit
  • scuttle
  • Shadows
  • Simpy
  • Smarking
  • Spurl
  • TailRank
  • Wists
  • YahooMyWeb

Previoushome

Keywords: Streaming media over the network, j2me introduction, J2ME Tutorial, j2me tutorial netbeans, j2me background process, j2me development kit, J2ME tutorial pdf, history of J2ME, basic J2ME, syntax use in J2ME, J2ME training courses, J2ME download.

HTML Quizzes
HTML Quiz
XHTML Quiz
CSS Quiz
TCP/IP Quiz
CSS 1.0 Quiz
CSS 2.0 Quiz
HLML Quiz
XML Quizzes
XML Quiz
XSL Quiz
XSLT Quiz
DTD Quiz
Schema Quiz
XForms Quiz
XSL-FO Quiz
XML DOM Quiz
XLink Quiz
XQuery Quiz
XPath Quiz
XPointer Quiz
RDF Quiz
SOAP Quiz
WSDL Quiz
RSS Quiz
WAP Quiz
Web Services Quiz
Browser Scripting Quizzes
JavaScript Quiz
VBScript Quiz
DHTML Quiz
HTML DOM Quiz
WMLScript Quiz
E4X Quiz
Server Scripting Quizzes
ASP Quiz
PERL Quiz
SQL Quiz
ADO Quiz
CVS Quiz
Python Quiz
Apple Script Quiz
PL/SQL Quiz
SQL Server Quiz
PHP Quiz
.NET (dotnet) Quizzes
Microsoft.Net Quiz
ASP.Net Quiz
.Net Mobile Quiz
C# : C Sharp Quiz
ADO.NET Quiz
VB.NET Quiz
VC++ Quiz
Multimedia Quizzes
SVG Quiz
Flash Quiz
Media Quiz
SMIL Quiz
Photoshop Quiz
Gimp Quiz
Matlab Quiz
Gnuplot Programming Quiz
GIF Animation Quiz
Scientific Visualization Quiz
Graphics Quiz
Web Building Quizzes
Web Browsers Quiz
Web Hosting Quiz
W3C Quiz
Web Building Quiz
Web Quality Quiz
Web Semantic Quiz
Web Careers Quiz
Weblogic Quiz
SEO Quiz
Web Site Hosting Quiz
Domain Name Quiz
Java Quizzes
Java Quiz
JSP Quiz
Servlets Quiz
Struts Quiz
EJB Quiz
JMS Quiz
JMX Quiz
Eclipse Quiz
J2ME Quiz
JBOSS Quiz
Programming Langauges Quizzes
C Quiz
C++ Quiz
Visual Basic Quiz
Data Structures Using C Quiz
Cobol Quiz
Assembly Language Quiz
Mainframe Quiz
Forth Programming Quiz
Lisp Programming Quiz
Pascal Quiz
Delphi Quiz
Fortran Quiz
OOPs Quiz
Data Warehousing Quiz
CGI Programming Quiz
Emacs Quiz
Gnome Quiz
ILU Quiz
Soft Skills Quizzes
Communication Skills Quiz
Time Management Quiz
Project Management Quiz
Team Work Quiz
Leadership Skills Quiz
Corporate Communication Quiz
Negotiation Skills Quiz
Database Quizzes
Oracle Quiz
MySQL Quiz
Operating System Quizzes
BSD Quiz
Symbian Quiz
Unix Quiz
Internet Quiz
IP-Masquerading Quiz
IPC Quiz
MIDI Quiz
Software Testing Quizzes
Testing Quiz
Firewalls Quiz
SAP Module Quizzes
ERP Quiz
ABAP Quiz
Business Warehousing Quiz
SAP Basis Quiz
Material Management Quiz
Sales & Distribution Quiz
Human Resource Quiz
Netweaver Quiz
Customer Relationship Management Quiz
Production and Planning Quiz
Networking Programming Quizzes
Corba Quiz
Networking Quiz
Microsoft Office Quizzes
Microsoft Word Quiz
Microsoft Outlook Quiz
Microsoft PowerPoint Quiz
Microsoft Publisher Quiz
Microsoft Excel Quiz
Microsoft Front Page Quiz
Microsoft InfoPath Quiz
Microsoft Access Quiz
Accounting Quizzes
Financial Accounting Quiz
Managerial Accounting Quiz
Testimonials | Contact Us | Link to Us | Site Map
Copyright 2008. Academic Tutorials.com. All rights reserved Privacy Policies | About Us
Our Portals : Academic Tutorials | Best eBooksworld | Beyond Stats | City Details | Interview Questions | Discussions World | Excellent Mobiles | Free Bangalore | Give Me The Code | Gog Logo | Indian Free Ads | Jobs Assist | New Interview Questions | One Stop FAQs | One Stop GATE | One Stop GRE | One Stop IAS | One Stop MBA | One Stop SAP | One Stop Testing | Webhosting in India | Dedicated Server in India | Sirf Dosti | Source Codes World | Tasty Food | Tech Archive | Testing Interview Questions | Tests World | The Galz | Top Masala | Vyom | Vyom eBooks | Vyom International | Vyom Links | Vyoms | Vyom World
Copyright 2003-2017 Vyom Technosoft Pvt. Ltd., All Rights Reserved.