Why Java is Portable

1
Why Java is Portable

• https//www.besanttechnologies.com/training-course
  s/java-training

2
Java

• Java is a programming language that produces
  software for multiple platforms.
• When a programmer registers a Java application,
  compiled code (known as bytecode) runs on most
  operating systems (OS), including Windows, Linux,
  and Mac. Java derives much of its syntax from C
  and C programming languages.
• Java is only Indonesia's fourth largest island,
  but contains more than half of the country's
  population and dominates it politically and
  economically.

3
Features of Java

• The main reason behind the creation of Java was
  to bring portability and security functionality
  to a computer language.
• In addition to these two main features, there
  were many other features that played an important
  role in shaping the final form of this excellent
  language, and therefore one of the reasons for
  Java security.
• Of course, every time javacode is compiled, the
  compiler generates a byte code.

4
Java is a portable

• The idea is that the Java language is portable
  (or, more accurately, compiled byte code is
  portable). You are sure that each VM requires a
  specific implementation for a specific hardware
  profile.
• However, once this effort has been made, all Java
  byte code will be executed on this platform.
• Java source code is compiled in bytecode when
  using the javac compiler. The bytecode is saved
  to disk with the file extension .class.

5
Java is a portable

• The Java platform differs from most other
  platforms in that it is a software-based platform
  that runs on other hardware-based platforms. It
  has two components
• 1. Runtime environment
• 2. API (Application Programming Interface)
• Java code can run on various platforms, for
  example, Windows, Linux, Sun Solaris, Mac / OS,
  etc.

6
Language using Java

• The Java compiler provided by Oracle is written
  in Java. Basically, Java is using C through the
  native Java API.
• You can check the source code of any class in
  Java as the Object class and check if you want to
  use the C language they called api native in
  java.
• Java runs on the JVM virtual machine - java.
  "Write Once, Turn Anywhere" (WORA) or sometimes
  "Write Once, Turn Anywhere" (WORE) was a motto
  created by Sun Microsystems to illustrate the
  benefits of the Java cross platform.

7
Java provides three distinct types of portability

• Source code portability A given Java program
  must produce identical results, CPU, operating
  system, or underlying Java compiler.
• CPU architecture portability Today's Java
  compilers produce object code (called byte code)
  for a CPU that doesn't exist yet. For each actual
  CPU on which Java programs are to be executed, a
  Java interpreter or virtual machine executes code
  J.
• OS / GUI Java solves this problem by providing a
  set of library functions (contained in libraries
  provided by Java, such as awt, util, and lang)
  that converge with an imaginary operating system
  and an imaginary GUI.

8
Java program structure

• Java program structure is the standard format
  released by the language developer for the
  industry programmer .
• Sun Micro System has prescribed the following
  structure for Java programmers for the
  development of Java applications. A package is a
  collection.
• The Java data structure is technically
  different than the C and Pascal versions, because
  the Java data structure is a Class instead of
  a struct or a record. Now it has private data and
  public methods.