Java Virtual Machine


Java virtual machine

[¦jäv·ə ‚vər·chə·wəl mə′shēn] (computer science) An interpreter that translates Java bytecode into actual machine instructions in real time. Abbreviated JVM.

Java Virtual Machine

(language, architecture)(JVM) A specification for softwarewhich interprets Java programs that have been compiled intobyte-codes, and usually stored in a ".class" file. The JVMinstruction set is stack-oriented, with variableinstruction length. Unlike some other instruction sets, theJVM's supports object-oriented programming directly byincluding instructions for object method invocation (similarto subroutine call in other instruction sets).

The JVM itself is written in C and so can be ported to runon most platforms. It needs thread support and I/O (fordynamic class loading). The Java byte-code is independentof the platform.

There are also some hardware implementations of the JVM.

Specification.

Sun's Java chip.

Java Virtual Machine

Software from Oracle that converts a program in Java bytecode (intermediate language) into machine language and executes it. The Java Virtual Machine (JVM) is the runtime engine of the Java Platform, which allows any program written in Java or other language compiled into Java bytecode to run on any computer that has a native JVM. JVMs run in both clients and servers, and the Web browser can activate the JVM when it encounters a Java applet.

The JVM includes a just-in-time (JIT) compiler that converts the bytecode into machine language so that it runs as fast as a native executable. The compiled program can be cached in the computer for reuse.

Microsoft had its own Java Virtual Machine (JVM) for several years, but terminated support at the end of 2007. See applet, HotSpot JVM, Java, Java Runtime Environment, bytecode and intermediate language.