Java Example Presentation of a Language

Background Conception: Java began as a language for embedded processors in consumer electronics, such as VCR, game boxes, PDA. Project started at Sun Microsystems around After surveying existing languages they decided to develop a new one, named "Oak". Design team was headed by James Gosling, well- known software architect who designed the Emacs editor and worked on NeWS windowing system (a flop)

Design Goals Goals were dictated by the application to consumer electronics, which would have a minimal processor, little memory, no disk (only EPROM or Flash memory), and limited power.  small, portable language.  language must be simple, low memory requirement, efficient implementation.  must by reliable (consumers won't tolerate electronics that crash or fail)  secure

Evolution  "Oak" failed to attract many customers; at the time, the demand for intelligent devices was too small and embedded processors not widely used in C.E.  Coincidentally, the Internet boom started along with demand for a portable, small, secure language for distributed Web applications.  "Oak" was renamed to Java.

Characteristics  An object-oriented language with syntax similar to C++.  All code must be contained in classes.  Has both primitive datatypes (for efficiency) and object types, defined by classes.  "interfaces": separate specification of behavior from implementation.  Restrictions compared to C++: eliminates pointers and referencing (reliability, security), no multiple inheritance (efficiency), all arguments pass-by-value.  Automatic garbage collection.  Strong type checking.

More Characteristics  Configurable security manager to limit access to system resources.  Includes threads and thread synchronization for multi- threaded applications.  Some syntax restrictions to prevent common programming errors, for example, "boolean" cannot be converted into any other type. This avoids errors like this: if ( x = 0 ) return y;// should be "x == 0"  Three Implementations based on same core language: Micro Edition - for embedded applications Standard Edition - standard apps, web apps. Enterprise Edition - adds enterprise features,...

Contributions and Impact  An enormous success, thanks to availability of free compiler and run-time (JVM), extensive class libraries (API), graphics, excellent online documentation and tutorial. satisfied a need for alternative in creating Web apps and easily distributed programs. extension to server-side apps such as JSP  Contributions to Languages most ideas already known, but Java combined them intelligently, including clever dual type system, security features, and a very good API.

Sample Program  to be added...

Resources  - Sun's Java site. Has extensive downloads and documentation for Java.  and dev.java.net is a community site where people contribute knowledge and collaborate on Java technology. Lots of information and help available here. Many good learning tools, weblogs, community discussions.  Java Community Process ( is where Java standards are developed by a "community process". The Java EE standard was (and is) developed here. Java Community Process