1. Java Example Presentation of a Language

2. 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 1990. 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)

3. 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

4. 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.

5. 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.

6. 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,...

7. 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.

8. Sample Program  to be added...

9. Resources  http://java.sun.com - Sun's Java site. Has extensive downloads and documentation for Java.  www.java.net 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. www.java.netdev.java.net  Java Community Process (www.jcp.org) is where Java standards are developed by a "community process". The Java EE standard was (and is) developed here. Java Community Process