Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Java Overview (for Silberschatz chapter 3, section 3.7) 2/11/02 – NMG+ Note: all diagrams taken from PPT slide file for “Applied Operating Systems Concept”, 1st ed.,by Silberschatz et. al., Wiley Publisher. Java language characteristics: “pure” object oriented architecture-neutral distributed Multithreaded Language syntax is “C-like” – Evolved out of C just as C++ Compiled output files (*.class) contain “bytecode” which will run on any implementation of the “Java Virtual Machine” (JVM) – platform independent. JVM is an interpreter that interprets the bytecode – analogous to interpretive BASIC. Java: originally focused on Internet programming due to support of “applets” – programs that run within (or under) a web browser. Can also write and compile “stand-alone” programs which will run from the command line in the context of JVM Java: is a multithreaded language: multiple “threads” of control or flows within a given Java “program module” ... threads actually reside in the JVM. Java API: A large set pr “library” of useful utilities and other programs which can be incorporated and used in any user program – analogous to the standard /runtime libraries for C language. Two API’s: base (graphics, I/O, etc) and standard extension API (security, media and others). Java Virtual Machine: Class loader loads compiled programs of type .class Interpreter executes bytecode words - one at a time, or it maybe a ==> “Just-In-Time” compiler that turns bytecode words into native machine language (an incremental compiler). Java platform consists of JVM and Java API. The java platform provides machine independence and portability of compiled classes. Java is portable, since Java programs are isolated from the hardware & software using “byte” code in “Java Virtual Machine (JVM). Java Development environment: