A Java compiler is a

compiler In computing, a compiler is a computer program that translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs tha ...

for the programming language

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

. The most common form of output from a Java compiler is

Java class file A Java class file is a file (with the filename extension) containing Java bytecode that can be executed on the Java Virtual Machine (JVM). A Java class file is usually produced by a Java compiler from Java programming language source files ...

s containing platform-neutral

Java bytecode In computing, Java bytecode is the bytecode-structured instruction set of the Java virtual machine (JVM), a virtual machine that enables a computer to run programs written in the Java programming language and several other programming langua ...

, but there are also compilers that output optimized native machine code for a particular hardware/

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

combination, most notably the now discontinued GNU Compiler for Java. Most Java-to-bytecode compilers do virtually no

optimization Mathematical optimization (alternatively spelled ''optimisation'') or mathematical programming is the selection of a best element, with regard to some criterion, from some set of available alternatives. It is generally divided into two subfi ...

, leaving this until run time to be done by the

Java virtual machine A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally describe ...

(JVM). The JVM loads the class files and either interprets the

bytecode Bytecode (also called portable code or p-code) is a form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (norma ...

or just-in-time compiles it to

machine code In computer programming, machine code is any low-level programming language, consisting of machine language instructions, which are used to control a computer's central processing unit (CPU). Each instruction causes the CPU to perform a ve ...

and then possibly optimizes it using

dynamic compilation Dynamic compilation is a process used by some programming language implementations to gain performance during program execution. Although the technique originated in Smalltalk,Peter L. Deutsch and Alan Schiffman. "Efficient Implementation of the ...

. A standard on how to interact with Java compilers programmatically was specified in JSR 199.

References

External links

Sun's OpenJDK javac page
* Stephan Diehl
"A Formal Introduction to the Compilation of Java"
''Software - Practice and Experience'', Vol. 28(3), pages 297-327, March 1998. Java specification requests {{compu-prog-stub

See also

References

External links