This page provides an introductory overview of the JDK
directories and the files they contain. Note that the file
structure of the JRE is identical to that of the JDK's
This section describes the most important files and directories required to develop applications for the Java platform.
(Note that some of the directories that are not required include Java source code and C header files. These are mentioned in the Additional Files and Directories section.)
Assuming the JDK software is installed
/jdk1.7.0, here are some of the most important
src.zip, the archive of source code for the Java platform.
tools.jar, which contains non-core classes for support of the tools and utilities in the JDK. Also includes
dt.jar, the DesignTime archive of BeanInfo files that tell interactive development environments (IDE's) how to display the Java components and how to let the developer customize them for an application.
/jdk1.7.0/bin. The java launcher tool serves as an application launcher (and replaced the old jre tool that shipped with 1.1 versions of the JDK). This directory does not need to be in the PATH environment variable.
rt.jar-- the bootstrap classes (the RunTime classes that comprise the Java platform's core API).
charsets.jar-- character-conversion classes.
extsubdirectory (described below) there are several additional resource subdirectories not described here.
localedata.jar-- locale data for
java.policy) and security properties (
.so(shared object) files used by the Solaris version of the Java platform.
.sofile used by the Java HotSpot™ Client Virtual Machine, which is implemented with Java HotSpot™ technology. This is the default VM.
.sofile used by the Java HotSpot™ Server Virtual Machine.
lib/applet/directory. This reduces startup time for large applets by allowing applet classes to be pre-loaded from the local file system by the applet class loader, providing the same protections as if they had been downloaded over the net.
This section describes the directory structure for Java source code, C header files, and other additional directories and files.
The additional files and directories shown above are:
Note: Demos and samples that show you how to program for the Java platform are available as a separate download at Java SE Downloads. These are available as separate .tar.z compressed packages and .tar.gz compressed binaries. Like other 64-bit bundles on Solaris, the 64-bit demos and samples bundles on Solaris expect the 32-bit demos and samples bundles to also be installed.