What is Java?What is Java?
- Java™
An object-oriented programming language released in 1995 by Sun Microsystems Inc.
Java applications are distributed as byte-code, an intermediate format that is platform independent; byte-code is interpreted and executed inside a JVM. This means that as long as an appropriate JVM implementation is available, the same Java application can run on multiple devices. - Source Code
- Binary
- Java Byte-Code
- Application Program Interface (API)
A collection of commands and functions that can be used when developing software. Also refers to the rules defining the procedure for using such commands in a program.
- JavaTM Applications
An application written in the Java programming language, distributed in an intermediate format known as byte-code and interpreted and executed by a JVM.
Also known by the following names:- MIDP compatible Java application: a MIDlet
- DoJa (NTT DoCoMo Java API) compatible Java application: an i-appli
- KDDI ezplus (KDDI Profile) compatible Java application: an EZ appli JavaTM
- Sprint PCS MUGlet
For more details about source code, binary, and Java byte code, please review to the following descriptions.
Source code allows a software developer to tell the computer how to do something, given reasonably easy to understand instructions. The developer writes their code, such as:
The developer then needs to compile this code to make it readable by a computer, rather than a human. Computers are digital, meaning they interpret everything as a 0 or a 1. To "compile the source code" describes the transformation of human readable source code (as shown above), into a string of 0s and 1s (binary).
The basic steps for a program written in a language such as C or C++ are:
These 0s and 1s have a specific order for any particular processor (like an Intel Pentium). In addition, an Operating System also affects how source code should be compiled. Therefore, for developing software for a variety of complex platforms such as mobile handsets, it becomes very difficult to manage all of the different binary versions necessary to support each platform. There are sometimes different processors in the mobile phones but in addition there are also many different operating systems on these handsets.
Either changes in the processor or changes to the operating system can make the binaries incompatible and therefore cause the application to fail to execute.
Given these complexities which are especially important for the mobile phone market, the idea of utilizing a language that is independent from the underlying platform became very popular. This is where Java fits in, as it makes the compiled code independent from the underlying processor and operating system.
The way this is done is to compile the source code to a consistent set of 0s and 1s (binary), but this binary does not comply with a specific processor or operating system. Instead, this independent code (known as Java byte-code) complies with a virtual machines environment, instead of a specific physical one.
The Virtual Machine is one component of our product JBlend™ . Therefore, JBlend™ enables Java to run on the mobile phones, allowing Java byte-code based programs to execute on any phone, regardless of the underlying processor or operating system. This is shown in the diagram below.
