A Java compiler is a compiler for the programming language Java. The most common form of output from a Java compiler is Java class files containing platform-neutral Java bytecode, but there are also compilers that emit optimized native machine code for a particular hardware/operating system combination.

Most Java-to-bytecode compilers, Jikes being a well known exception, do virtually no optimization, leaving this until run time to be done by the JRE^{[citation needed]}.

The Java virtual machine (JVM) loads the class files and either interprets the bytecode or just-in-time compiles it to machine code and then possibly optimizes it using dynamic compilation.

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

Major Java compilers

As of 2012, the following are major Java compilers:^{[citation needed]}

• The Java Programming Language Compiler (javac), included in the Java Development Kit from Oracle Corporation, open-sourced since 13 November 2006.
• GNU Compiler for Java (GCJ), a part of the GNU Compiler Collection, which compiles C, C++, Fortran, Pascal and other programming languages besides Java. It can also generate native code using the back-end of GCC.
• Eclipse Compiler for Java (ECJ), an open source incremental compiler used by the Eclipse project.

See also

Java portal

• Jaccelerator - a semantic compressor with Java compiler^[1]

References

External links

• Sun's OpenJDK javac page
• JSR 199 Java Compiler API Java Specification Request for invoking the Java compiler from a Java program
• A Formal Introduction to the Compilation of Java, Stephan Diehl, "Software - Practice and Experience", Vol. 28(3), pages 297-327, March 1998.