Compiler Package Overview

javax.annotation.processing: Facilities for declaring annotation processors and for allowing annotation processors to communicate with an annotation processing tool environment.
javax.lang.model and subpackages: Classes and hierarchies of packages used to model the Java programming language.
javax.tools: Provides interfaces for tools which can be invoked from a program, for example, compilers.

com.sun.source and subpackages: Representation of the compiler syntax trees.
(top level): The javac main program and command-line entry point provides supported API for very simple invocation of the compiler.

api: Implementation of JavaCompiler and other API in javax.tools.
code: Representation of the semantic elements of a Java program, such as symbols, scopes and types, implementing API in javax.lang.model.*.
comp: Primary processing phases for the compiler, such as attribution, flow analysis, "desugaring" and erasure.
file: Access to the native file system, including the implementation of javax.tools.StandardFileManager.
file: Access to the native file system using the java.nio.file API, including JavacPathFileManager.
jvm: Classes for reading and writing class files, and the code generation phase of the compiler.
main: Main driver code for any compilation. It provides option decoding and sequences through the various steps for compilation.
model: Additional implementation classes for javax.lang.model.*.
parser: Read Java source code to generate syntax trees.
processing: Implementation classes for annotation processing API defined in javax.annotation.processing.*.
resources: Resource files for localized messages and version info.
tree: Representation and utility classes for the compiler's syntax trees, implementing API in com.sun.source.*.
util: Basic utility classes, including support for reporting diagnostics.