# All Classes

- All Classes Interface Summary Class Summary Exception Summary Error Summary
  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.