This document is the API specification for the Apache Commons Lang library.

Packages 
Package Description
org.apache.commons.lang
Provides highly reusable static utility methods, chiefly concerned with adding value to the java.lang classes.
org.apache.commons.lang.builder
Assists in creating consistent equals(Object), toString(), hashCode(), and compareTo(Object) methods.
org.apache.commons.lang.enums
Provides an implementation of the C style enum in the Java world.
org.apache.commons.lang.exception
Provides JDK 1.4 style Nested Exception functionality for those on prior Java versions.
org.apache.commons.lang.math
Extends java.math for business mathematical classes.
org.apache.commons.lang.mutable
Provides typed mutable wrappers to primitive values and Object.
org.apache.commons.lang.reflect
Accumulates common high-level uses of the java.lang.reflect APIs.
org.apache.commons.lang.text
Provides classes for handling and manipulating text, partly as an extension to java.text.
org.apache.commons.lang.time
Provides classes and methods to work with dates and durations.