# All Classes and Interfaces

Class
Description
ArrayUtils
Operations on arrays, primitive arrays (like `int[]`) and primitive wrapper arrays (like `Integer[]`).
BitField
Operations on bit-mapped fields.
BooleanUtils
Operations on boolean primitives and Boolean objects.
CharEncoding
Character encoding names required of every implementation of the Java platform.
CharRange
A contiguous range of characters, optionally negated.
CharSet
A set of characters.
CharSetUtils
Operations on `CharSet`s.
CharUtils
Operations on char primitives and Character objects.
ClassUtils
Operates on classes without using reflection.
CloneFailedException
Exception thrown when a clone cannot be created.
CompareToBuilder
Assists in implementing `Comparable.compareTo(Object)` methods.
CompositeFormat
Formats using one formatter and parses using a different formatter.
ConstructorUtils
Utility reflection methods focussed on constructors, modelled after `MethodUtils`.
DateFormatUtils
Date and time formatting utilities and constants.
DateUtils
A suite of utilities surrounding the use of the `Calendar` and `Date` object.
DoubleRange
`DoubleRange` represents an inclusive range of `double`s.
DurationFormatUtils
Duration formatting utilities and constants.
Enum
Abstract superclass for type-safe enums.
EnumUtils
Utility class for accessing and manipulating `Enum`s.
EqualsBuilder
Assists in implementing `Object.equals(Object)` methods.
ExceptionUtils
Provides utilities for manipulating and examining `Throwable` objects.
ExtendedMessageFormat
Extends `java.text.MessageFormat` to allow pluggable/additional formatting options for embedded format elements.
FastDateFormat
FastDateFormat is a fast and thread-safe version of `SimpleDateFormat`.
FieldUtils
Utilities for working with fields by reflection.
FloatRange
`FloatRange` represents an inclusive range of `float`s.
FormatFactory
Format factory.
Fraction
`Fraction` is a `Number` implementation that stores fractions accurately.
HashCodeBuilder
Assists in implementing `Object.hashCode()` methods.
IEEE754rUtils
Provides IEEE-754r variants of NumberUtils methods.
IllegalClassException
Thrown when an object is an instance of an unexpected type (a class or interface).
IncompleteArgumentException
Thrown to indicate an incomplete argument to a method.
IntRange
`IntRange` represents an inclusive range of `int`s.
JVMRandom
`JVMRandom` is a wrapper that supports all possible Random methods via the `Math.random()` method and its system-wide `Random` object.
LocaleUtils
Operations to assist when working with a `Locale`.
LongRange
`LongRange` represents an inclusive range of `long`s.
MethodUtils
Utility reflection methods focused on methods, originally from Commons BeanUtils.
Mutable
Provides mutable access to a value.
MutableBoolean
A mutable `boolean` wrapper.
MutableByte
A mutable `byte` wrapper.
MutableDouble
A mutable `double` wrapper.
MutableFloat
A mutable `float` wrapper.
MutableInt
A mutable `int` wrapper.
MutableLong
A mutable `long` wrapper.
MutableObject
A mutable `Object` wrapper.
MutableShort
A mutable `short` wrapper.
Nestable
An interface to be implemented by `Throwable` extensions which would like to be able to nest root exceptions inside themselves.
NestableDelegate
A shared implementation of the nestable exception functionality.
NestableError
The base class of all errors which can contain other exceptions.
NestableException
The base class of all exceptions which can contain other exceptions.
NestableRuntimeException
The base class of all runtime exceptions which can contain other exceptions.
NotImplementedException
Thrown to indicate that a block of code has not been implemented.
NullArgumentException
Thrown to indicate that an argument was `null` and should not have been.
NumberRange
`NumberRange` represents an inclusive range of `Number` objects of the same type.
NumberRange
Deprecated.
Use one of the Range classes in org.apache.commons.lang.math.
NumberUtils
Provides extra functionality for Java Number classes.
NumberUtils
Deprecated.
Moved to org.apache.commons.lang.math.
ObjectUtils
Operations on `Object`.
ObjectUtils.Null
Class used as a null placeholder where `null` has another meaning.
RandomStringUtils
Operations for random `String`s.
RandomUtils
`RandomUtils` is a wrapper that supports all possible `Random` methods via the `Math.random()` method and its system-wide `Random` object.
Range
`Range` represents a range of numbers of the same type.
ReflectionToStringBuilder
Assists in implementing `Object.toString()` methods using reflection.
SerializationException
Exception thrown when the Serialization process fails.
SerializationUtils
Assists with the serialization process and performs additional functionality based on serialization.
StandardToStringStyle
Works with `ToStringBuilder` to create a `toString`.
StopWatch
`StopWatch` provides a convenient API for timings.
StrBuilder
Builds a string from constituent parts providing a more flexible and powerful API than StringBuffer.
StringEscapeUtils
Escapes and unescapes `String`s for Java, Java Script, HTML, XML, and SQL.
StringUtils
Operations on `String` that are `null` safe.
StrLookup
Lookup a String key to a String value.
StrMatcher
A matcher class that can be queried to determine if a character array portion matches.
StrSubstitutor
Substitutes variables within a string by values.
StrTokenizer
Tokenizes a string based based on delimiters (separators) and supporting quoting and ignored character concepts.
SystemUtils
Helpers for `java.lang.System`.
ToStringBuilder
Assists in implementing `Object.toString()` methods.
ToStringStyle
Controls `String` formatting for `ToStringBuilder`.
UnhandledException
Thrown when it is impossible or undesirable to consume or throw a checked exception.
Validate
This class assists in validating arguments.
ValuedEnum
Abstract superclass for type-safe enums with integer values suitable for use in `switch` statements.
WordUtils
Operations on Strings that contain words.