Java Platform, Micro Edition

Java Platform, Micro Edition, abbreviated Java ME [ dʒɑ ː ˌ və ɛmi ː ], formerly known as Java Platform 2, Micro Edition or J2ME short, is an implementation of the Java programming language for embedded consumer products such as mobile phones or PDAs. It is defined in the Java Specification Requests 30 and 37

The basis of Java ME thereby form the configurations and profiles.

With J2ME, it is possible to run applications on mobile devices, regardless of manufacturer / model / operating system, because these applications are executed by the Java Runtime independently.

Configurations

The configurations provide various libraries and a virtual machine. Such a configuration may be the Connected Device Configuration (CDC ), or, in mobile devices, the Connected Limited Device Configuration ( CLDC ). Currently, only these two configurations are available. The CLDC is observed a very large increase, as almost every current phone uses this configuration in combination with the Mobile Information Device Profile.

Profiles

Profiles are the APIs, which gives it a configuration. So there is the Mobile Information Device Profile ( MIDP ), especially for mobile phones. Java applications that have been developed based on the MIDP, also called MIDlet short. It may be, for example, the frequently advertised since 2002/2003 » java games for mobile phones ." Another profile is the Information Module Profile ( IMP), which is a subset of MIDP and is intended for machine to machine communication. As its application as an example can be seen a vending machine, which would be filled and then this profile would report somewhere.

Meanwhile, there are also MIDP2.0. This version has been expanded to meet the needs especially of game developers. Another version of Java ME is DoJa, the Java version of the Japanese mobile operator NTT DoCoMo, which comes on i-mode handsets to use.

Extensions

For many applications, the simple configurations are not enough because they do not provide access to the internal functions of the device. Therefore, there are many extensions that allow the address book of a mobile phone (JSR -75) or the built-in Bluetooth functionality (Java BlueTooth Wireless Technology: JSR-82/JABWT ) to use. The necessary extensions are carried out under the Java Community Process (JCP ). Well-known manufacturers such as Nokia, Siemens and IBM provide change requests and then take the lead ( the lead ) in the implementation. For example, IBM and PalmSource as a leader responsible for the change request JSR -75 " PDA Optional Packages for the J2ME (TM ) Platform".

History

Since 22 December 2006, the source code of Sun's reference implementation of Java ME is disclosed and is distributed under the terms of the GNU General Public License (GPL ) as part of a project called phoneME as free software.

Compared to CNet Sun announced in October 2007 to give up the Java ME platform in favor of Java Standard Edition. Reason for this is that the devices for the Java ME was once created, more and more powerful have been. However, the conversion is not going to happen all at once, but will take place over the next few years.

More Java platforms

Java Platform, Standard Edition
Java Platform, Enterprise Edition

.NET Compact Framework

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