Presentation on Java Basic
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Java is a versatile, object-oriented programming language designed for cross-platform functionality, allowing code to be written once and run anywhere. Developed in the early 1990s, it was originally intended for interactive television and has since evolved through multiple major versions. The current implementation, maintained by Oracle, includes a Java Runtime Environment for users and a Java Development Kit for developers, with improvements in performance through techniques like just-in-time compilation.
Presentation on Java Basic
- 2. JAVA Java is a functional computer programming language that is concurrent, class-based, object-oriented, and specifically designed to have as few implementation dependencies as possible. It is intended to let application developers "write once, run anywhere" meaning that code that runs on one platform does not need to be recompiled to run on another. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of computer architecture.
- 3. History James Gosling, Mike Sheridan, and Patrick Naughton initiated the Java language project in June 1991. Java was originally designed for interactive television, but it was too advanced for the digital cable television industry at the time. The language was initially called Oak after anoak tree that stood outside Gosling's office. Later the project went by the name Green and was finally renamed Java, from Java coffee, said to be consumed in large quantities by the language's creators. Gosling designed Java with a C/C++-style syntax that system and application programmers would find familiar.
- 4. Principles There were five primary goals in the creation of the Java language 1. It must be "simple, object-oriented and familiar“. 2. It must be "robust and secure“. 3. It must be "architecture-neutral and portable“. 4. It must execute with "high performance“. 5. It must be "interpreted, threaded, and dynamic“.
- 5. Versions Major release versions of Java, along with their release dates: 1. JDK 1.0 (January 21, 1996) 2. JDK 1.1 (February 19, 1997) 3. J2SE 1.2 (December 8, 1998) 4. J2SE 1.3 (May 8, 2000) 5. J2SE 1.4 (February 6, 2002) 6. J2SE 5.0 (September 30, 2004) 7. Java SE 6 (December 11, 2006) 8. Java SE 7 (July 28, 2011) 9. Java SE 8 (March 18, 2014)
- 6. Java platform One design goal of Java is portability, which means that programs written for the Java platform must run similarly on any combination of hardware and operating system with adequate runtime support. This is achieved by compiling the Java language code to an intermediate representation called Java bytecode, instead of directly to architecture-specific machine code. Java bytecode instructions are analogous to machine code, but they are intended to be executed by a virtual machine (VM) written specifically for the host hardware. End users commonly use a Java Runtime Environment (JRE) installed on their own machine for standalone Java applications, or in a web browser for Java applets. Standardized libraries provide a generic way to access host-specific features such as graphics, threading, and networking. A major benefit of using bytecode is porting. However, the overhead of interpretation means that interpreted programs almost always run more slowly than programs compiled to native executables would. Just-in-Time (JIT) compilers were introduced from an early stage that compile bytecodes to machine code during runtime.
- 7. Implementations Oracle Corporation is the current owner of the official implementation of the Java SE platform, following their acquisition of Sun Microsystems on January 27, 2010. This implementation is based on the original implementation of Java by Sun. The Oracle implementation is available for Microsoft Windows, Mac OS X, Linux and Solaris. Because Java lacks any formal standardization recognized by Ecma International, ISO/IEC, ANSI, or other third-party standards organization, the Oracle implementation is the de facto standard. The Oracle implementation is packaged into two different distributions: The Java Runtime Environment (JRE) which contains the parts of the Java SE platform required to run Java programs and is intended for end users, and the Java Development Kit (JDK), which is intended for software developers and includes development tools such as the Java compiler, Javadoc, Jar, and a debugger.
- 8. Performance Programs written in Java have a reputation for being slower and requiring more memory than those written in C++. However, Java programs' execution speed improved significantly with the introduction of Just-in-time compilation in 1997/1998 for Java 1.1, the addition of language features supporting better code analysis (such as inner classes, the StringBuilder class, optional assertions, etc.), and optimizations in the Java virtual machine, such as HotSpot becoming the default for Sun's JVM in 2000. Some platforms offer direct hardware support for Java; there are microcontrollers that can run Java in hardware instead of a software Java virtual machine, and ARM based processors can have hardware support for executing Java bytecode through their Jazelle option.