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 gives 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 2019, 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.
• Eclipse Compiler for Java (ECJ), an open source incremental compiler used by the Eclipse project.

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
• Stephan Diehl, "A Formal Introduction to the Compilation of Java", Software - Practice and Experience, Vol. 28(3), pages 297-327, March 1998.