Saturday, February 22, 2014

Basics about JRE (Java Runtime environment)

Definition - What does Java Runtime Environment (JRE) mean?

The Java Runtime Environment (JRE) is a set of software tools for development of Java applications. It combines the Java Virtual Machine (JVM), platform core classes and supporting libraries.

JRE is part of the Java Development Kit (JDK), but can be downloaded separately. JRE was originally developed by Sun Microsystems Inc., a wholly-owned subsidiary of Oracle Corporation.

Also known as Java runtime.

Components of Java Runtime Environment (JRE)

JRE consists of the following components:
  • Deployment technologies, including deployment, Java Web Start and Java Plug-in.
  • User interface toolkits, including Abstract Window Toolkit (AWT), Swing, Java 2D, Accessibility, Image I/O, Print Service, Sound, drag and drop (DnD) and input methods.
  • Integration libraries, including Interface Definition Language (IDL), Java Database Connectivity (JDBC), Java Naming and Directory Interface (JNDI), Remote Method Invocation (RMI), Remote Method Invocation Over Internet Inter-Orb Protocol (RMI-IIOP) and scripting.
  • Other base libraries, including international support, input/output (I/O), extension mechanism, Beans, Java Management Extensions (JMX), Java Native Interface (JNI), Math, Networking, Override Mechanism, Security, Serialization and Java for XML Processing (XML JAXP).
  • Lang and util base libraries, including lang and util, management, versioning, zip, instrument, reflection, Collections, Concurrency Utilities, Java Archive (JAR), Logging, Preferences API, Ref Objects and Regular Expressions.
  • Java Virtual Machine (JVM), including Java HotSpot Client and Server Virtual Machines.
For more clearity please refer below diagram :


  • Why is JVM called virtual ?
  • The JVM is called “virtual” because it provides a machine interface that does not depend on the underlying operating system and machine hardware architecture. This independence from hardware and operating system is a cornerstone of the write-once run-anywhere value of Java programs.


1 comment:

  1. Wow never saw you started this. Keep the writing going :)