ch-5 # Java Environment. смотреть онлайн

All three JDK, JRE and JVM are interdependent and there is no common point so it is not effective to state their difference in the tabular form however we will discuss these in the following paragraphs.

JVM

JVM is the abbreviation for Java virtual machine which is a specification that provides a runtime environment in which Java byte code can be executed i.e it is something that is abstract and its implementation is independent to choose the algorithm and has been provided by Sun and other companies. It is JVM that is responsible for converting Byte code to machine-specific code. It can also run those programs which are written in other languages and compiled to Java bytecode. The JVM performs the mentioned tasks: Loads code, Verifies code, Executes code, Provides a runtime environment.

JRE

JRE is a Java runtime environment that is the implementation of JVM i.e the specifications which are defined in JVM are implemented and creates a corresponding environment for the execution of code.JRE comprises mainly java binaries and other classes to execute the program alike of JVM it physically exists. Along with Java binaries, JRE also consists of various technologies of deployment, user interfaces to interact with code executed, some base libraries for different functionalities and language and util based libraries.

JDK

JDK is an abbreviation for Java Development Kit which includes all the tools, executables and binaries required to compile, debug and execute a Java Program.JDK is platform-dependent i.e there are separate installers for Windows, Mac, and Unix systems.JDK includes both JVM and JRE and is entirely responsible for code execution. It is the version of JDK which represent a version of Java.