MicroEmulator

MicroEmulator

Demo MIDlet running in MicroEmulator
Other names	MicroEMU
Original author(s)	Bartek Teodorczyk
Developer(s)	Bartek Teodorczyk, Vlad Skarzhevskyy
Initial release	March 31, 2006 (2006-03-31)
Final release	2.0.4 / January 14, 2010 (2010-01-14)
Preview release	3.0.0-SNAPSHOT.112 / May 24, 2013 (2013-05-24)
Repository	github.com/barteo/microemu
Written in	Java
Size	1.1 MB
Type	Emulator
License	GNU Lesser General Public License version 2.1; Apache License version 2.0
Website	microemu.org

MicroEmulator (also MicroEMU) — is a free and open-source platform independed J2ME emulator allowing to run MIDlets (applications and games) on any device with compatible JVM. It is written in pure Java as an implementation of J2ME in J2SE.

History

In November 2001, MicroEmulator project has been created on SourceForge.

On 31 March 2006, MicroEmulator version 1.0 has been released.

In November 2009, project moved to code.google.com, and after Google closed it, development moved to GitHub.

On 10 January 2010, the last stable version 2.0.4 has been released.

On 24 May 2013, the last preview version 3.0.0-SNAPSHOT.112 has been released.

After 2014, MicroEMU technology has been acquired by All My Web Needs company and all the MicroEmulator's docs and binary builds has been removed from the official site.

All sources and binary previously released on SourceForge, Google Code and GitHub preserved as open-source, but development stalled since then.

Features

• Supports loading MIDlet from JAD or JAR file (locally stored or remotely accessed via URL)
• Supports MIDP 2.0 (CLDC-1.0 and CLDC-1.1), various Java APIs and JSRs (Java Specification Requests):
  • Generic Connection Framework API (GCF)
  • Record Management System API (RMS)
  • File Connection API (JSR 75)
  • Bluetooth API (JSR 82)
  • Wireless Messaging API (WMA, JSR 120)
  • Multimedia API (MMAPI, JSR 135)
  • Location API (LAPI, JSR 179)
  • LCDUI, Nokia and Siemens UI APIs
• Works with different GUI libraries (Swing, SWT, etc.)
• Platform independent (Linux, Mac OS, Windows, etc.)
• Supports insert PC clipboard text into MIDlet's text input fields (but not vice-versa; useful if need to input case sensitive text string or special characters in MIDlet)
• Supports control MIDlet via on-screen (virtual) or real keyboard keys, touch screen and mouse gestures, mouse scroll wheel and keys (also allows remap keys' scancodes, see "Skin, screen and window size configuration" section bellow)
• Screencast recording as GIF animation
• Record Store Manager (allows to log MIDlet's internal system calls to RMS API)
• Debug mode (allowing to trace and record issues)
• Allows to setup proxy for network connections
• Runs in headless mode
• Many CLI options

JSR lib loading

By default MicroEmulator does not loads all distributed JSRs; user should load it per launch via custom commands instead.

File system access

On initial startup MicroEmulator does not loads JSR 75 lib, and as a result MIDlets has no access to file system.

To grant access to file system do the next steps:

1. Run MicroEmulator for the first time and close it — it will create config2.xml file (on Linux, in ~/.microemulator/ folder)
2. Open this XML-file and add after </windows> section add <extensions> section with the next strings at the end and save it:

   <config>
       ...
       </windows>
       <extensions>
           <extension>
               <className>org.microemu.cldc.file.FileSystem</className>
               <properties>
                   <property VALUE="<path>/<to>/<folder>" NAME="fsRoot"/>
               </properties>
           </extension>
       </extensions>
       <recordStoreManager CLASS="org.microemu.app.util.FileRecordStoreManager"/>
   </config>
   

   (where <folder> would be a root of the mounted files system to be recognized by MIDlet)
3. Launch MicroEmulator with loading JSR 75 lib; on Linux, use the next command via terminal (or add it to microemulator.desktop file):

   java -cp <path>/<to>/microemulator.jar:<path>/<to>/lib/microemu-jsr-75.jar org.microemu.app.Main
   

   (on Windows use ; instead of : to separate path to lib to be loaded; to load more libs just add it each after each in a row)

After launch opened MIDlets would has access to <folder> content with read and wright permissions.

Java applet for Web

Results of Acid3 test run in Opera Mini running in MicroEmulator applet

MicroEmulator allows convert any J2ME app into Java applet, that could be placed on web page. This feature used for demonstrating apps and games demos on vendors sites, but it requires JVM and Java Web Start plugin to be installed on user's PC or device.

Skin, screen and window size configuration

MicroEmulator allows interface customization with skins called "devices" (see "Options > Select device..." menu) and distributed with few skins:

• Default device — phone with 240x320 color screen and antialiazed text;
• Minimum device color — small phone with 128x128 color screen and non-antialiazed text;
• Minimum device — small phone with 128x128 monochrome screen and non-antialiazed text;
• Resizable device — full window color screen and antialiazed text (useful for use in full screen).

Each "device" skin consist of XML-files, that stores definitions of window size, keys layout and assignations (according scancodes), text rendering options, etc. Optionally, skin could include image textures for "device" background and keys animation on key click and key relax. All files of "device" skin should be packed into ZIP or JAR, and its possible to include few "devices" into single package.

Additionally its possible to show current MIDlet screen scaled (x2, x3 or x4) in separate window.

Limitiations

• MicroEmulator lacks support for few Java APIs and JSRs often used in j2ME games (and implemented in other emulators and MicroEmulator forks):
  • Mobile 3D Graphics API (M3G, JSR 184);
  • Scalable 2D Vector Graphics API (SVG, JSR 226);
  • Mascot Capsule 3D API.
• Some MIDlets may require other JSRs, that are not availabale for MicroEmulator yet.
• For input Cyrillic characters it might require to use special "device" skin.

Ports and forks

Android

MicroEmulator has an official support for Android platform. Also it is possible to convert J2ME MIDlet JAR-package into standalone Android Apk-package.

J2ME Loader — is an enhanced fork of MicroEmulator for Android.

JL-Mod — is an enhaced fork of J2ME Loader with the Mascot Capsule 3D API support.

iOS

Microemulator on iPhone crosscompiled with XMLVM
Working: List, Alert and TextBox
Video by AtoroGM on YouTube

MicroEmulator has been ported to iOS, but it requires to use iOS jailbreaking technique to install it on iPhone or other iOS device.

Mac

Microemulator officialy supports Mac OS, but there is also package in MacPorts repository.

Maemo

Opera Mini 4 / Java J2ME on Nokia n810 Internet Tablet - Maemo 4 (OS2008)
This is a demonstration of running Opera Mini web browser inisde Sun Java for ARM.
Video by Kajetan Krykwiński on YouTube

MicroEmulator has an official support for Maemo platform, and there is custom MicroEmulator devices skins (themed to Nokia S60 smartphones with 240x320 and 640x360 displays) made for Nokia N900.

Here is a command to launch MicroEmulator on Maemo with JSR 75 lib loaded, to grant MIDlets file system access:

microemulator -libraryjars /opt/maemo/usr/share/microemulator/lib/microemu-jsr-75.jar

MeeGo/Harmattan

KarinME — is a MicroEmulator front-end launcher for MeeGo/Harmattan platform, with a GUI written in QML.

mpowerplayer SDK

mpowerplayer SDK — is a freeware enhanced fork of MicroEmulator, initially created for MacOS as J2ME MIDP 1.0 emulator, later become a platform independed J2ME MIDP 2.0 emulator with own implementation of M3G (JSR 184) and SVG (JSR 226).

WMA (JSR 120) has been implemented for mpowerplayer SDK as an open-source library.

Development stalled after mpowerplayer SDK version 2.0.1185 release in 2007. ZIP of latest distribution package available for download from archived official website on Wayback Machine.

Usage

MicroEmulator as Opera Mini sandbox

Wikipedia website in Opera Mini 8 browser running in MicroEmulator with full-screen Eee PC device skin

• Web applet with Opera Mini MIDlet running inside MicroEmulator has been placed on Opera official website.
• MicroEmulator used together with Opera Mini MIDlet to browse Internet via metered networks and slow mobile GPRS connection on netbooks (such as Asus Eee PC), low-end PCs and other mobile devices.
• In some countries mobile network operators provided free traffic or very lowcost plan with unlimited traffic for Opera Mini and some social networks and services via its J2ME clients (like Facebook, Yandex Maps, etc.). Use of MicroEmulator together with Opera Mini or other app with free traffic plan allowed to browse Internet fully free on PC (with USB modem attached) at home or on netbook on the go.

MicroEmulator as J2ME SDK

• MicroEmulator, together with few MIDlets for programming directly on phone (J2ME SDK Mobile, Mobile BASIC, MIDletPascal, etc.), could be used as a fully complete J2ME SDK: it is possible to write MIDlet source code, compile and preverify Java class files, package all files and resources of MIDlet project into JAR with JAD, and then run built MIDlet for test and debug without even leaving MicroEmulator window. The only external dependency is a JVM installed on PC or device to run Microemulator itself.
• MicroEmulator could be used as alternative to Sun's and Oracle's JavaME emulators for various desktop Java IDE's. For the Eclipse ititially there was opensource bridge plugin EclipseME created, but Eclipse 1.7 and later got own bridge plugin.
• MicroEmulator available as org.microemu plugin for Apache Maven build automation tool.

Publications

• J2ME Building Blocks for Mobile Devices: White Paper on KVM and the Connected, Limited Device Configuration (CLDC) (PDF), Palo Alto, CA: Sun Microsystems, Inc., 19 May 2000
• Stefan, Haustein (14 July 2004), "ME4SE: A Pure Java Emulation of the Mobile Information Device Profile (MIDP)" (PDF), Siemens JavaTalks 2004 (Slides)
• Kroll, Michael (31 May 2007), J2ME Software Entwicklung und Fehlersuche (PDF) (Dipl.-Inf.(FH)) (in Swiss), Michael Kroll Consulting & Solutions{{citation}}: CS1 maint: unrecognized language (link)
• Smith, Micahel(tm) (2008), Browsers on the move: 2007-05 to 2008-06 (PDF) (Slides), W3C
• Tavares, Andre Luiz Camargos; Valente, Marco Tulio (2008-03-16). "A remote display system for Java-based mobile applications". Proceedings of the 2008 ACM symposium on Applied computing. ACM. pp. 1918–1922. doi:10.1145/1363686.1364150. ISBN 978-1-59593-753-7.
• Delwadia, Vipul (2009). RemoteME: Experiments in Thin-Client Mobile Computing (Thesis thesis). Victoria University (New Zealand).
• Virkus, Robert (18 September 2009). "Programming J2ME / Java ME Apps". Mobile Developer's Guide To The Galaxy (PDF). Bremen: Enough Software GmbH + Co. KG. pp. 14–22. Archived from the original (PDF) on 2 October 2009.
• Virkus, Robert (15 October 2009). "Programming J2ME / Java ME Apps". Mobile Developer's Guide To The Galaxy (PDF) (2nd Extended ed.). Bremen: Enough Software GmbH + Co. KG. pp. 21–29.
• Vávra, David (10 June 2009). GPS game for mobile framework Locify (PDF) (BA Thesis thesis). Czech Technical University in Prague.
• Fotouhi-Ghazvini, Faranak (20 March 2012), "Mobile Learning using Mixed Reality Games and a Conversational, Instructional and Motivational Paradigm", . (PhD Thesis), University of Bradford
• Padmanaban, Yogesh (2013). Learning API mappings for programming platforms (Thesis). New Brunswick: Rutgers University - Graduate School.
• Gokhale, Amruta; Ganapathy, Vinod; Padmanaban, Yogesh (May 2013). "Inferring likely mappings between APIs". 2013 35th International Conference on Software Engineering (ICSE). pp. 82–91. doi:10.1109/ICSE.2013.6606554. ISBN 978-1-4673-3076-3.
• Virkus, Robert (February 2015). "Java ME (J2ME)". Mobile Developer's Guide To The Galaxy (15th ed.). Bremen: Enough Software GmbH + Co. KG. pp. 82–90. ASIN B00BS6RIKU. Archived from the original (PDF) on 29 September 2015.
• Phong, Cao, Porting J2ME Apps to Nokia X Using J2ME Android Bridge

Video

• MicroEmu (J2ME emulation) on Linux on YouTube
• Alan Bazan. J2ME Emulator playlist on YouTube (in Spanish)

See also

• SquirrelJME (JavaME 8 VM for embedded device)
• KEmulator (J2ME emulator for Windows)
• FreeJ2ME (J2ME emulator for Libretro and RetroArch)
• ME2SE (J2ME APIs for J2SE, runs on Windows Mobile)
• ScummVM
• DOSBox
• PyPy
• Python for S60

External links

• Official website (Archived February 9, 2014, at the Wayback Machine)
• MicroEmulator on Blogger
• MicroEmulator at Google Code
• MicroEmulator on SourceForge
• MicroEmulator on GitHub
• MicroEmulator on Google Groups
• MicroEmulator package at the Maemo repository
• Microemulator-s60-skin package at the Maemo repository
• KarinME MeeGo/Harmattan package at the OpenRepos repository
• J2ME Loader Android package at the F-Droid repository
• mpowerplayer SDK 2.0.1185 (ZIP) at the Wayback Machine (archived December 22, 2011)
• waper.ru deathgrab (incomplete dump) at the Internet Archive (includes collection of MIDlets for J2ME programming)