Java Runtime Environment

Posted on September 8, 2016 By

The MIDP is the layer that contains API’ s Java stops connections of users in net, persistence of storage and the interface with the user. In set with the CLDC it is possible to get the applicatory functionality of the main one demanded by the mobile applications. The API’ s optional is functionalities adds specific that the devices will not be found in all, but that they possess its due importance. For (KEOGH 2003), to write programs in Java it is similar to the codification in C++, where the programmer constructs its code-source in an environment of integrated development or a specific publisher. After this process, the program is compiled. In this stage, the differences appear of the two languages.

The program written in C, after compiled, becomes an executable one that it can twirl in an appropriate machine, while the Java compiler converts the code-source into bytecode, which will be executed by Mquina Virtual Java (JVM). Specific instructions of machine are not enclosed in bytecode. Instead of this, they already they inhabit in the JVM, which is a specific machine. Although the Java compiler generates bytecode that he must be interpreted by the JVM in execution time, the number of instructions that need translation is generally minimum and already they had been optimized by the Java compiler. In the case of the J2ME, specifically in the CLDC, the used virtual machine it is KJava Virtual Machine (KVM), that it is part of the surrounding minor of execution time (JRE Java Runtime Environment) and is used in devices with memory and power of limited CPU 3. The KVM is similar to the JVM, for the fact of being the mechanism that the applicatory one executes and the mini-applicatory one developed with the Java technology.

The difference is that the KVM is used in cellular telephones and mobile devices, while the JVM is used in computers. Figure 1 – Architecture of the J2ME. The Java Edition Micron does not contain all the existing packages and classrooms in the Standard Java Edition or other versions of applicatory Java destined to the development of for desktop and/or servers. Of this form, applicatory to be created in J2ME it must directly be developed without such implemented resources or for the desenvolvedor. An example of the lack of resources is the support absence the numbers in floating-point, something importantssimo for the creation of electronic games. In other words, it is not possible to effect decimal calculations or to use things such as sine, coseno and tangent.