# Package org.apache.catalina.util

- Class Summary
  Class | Description
  --- | ---
  CharsetMapper | Utility class that attempts to map from a Locale to the corresponding character set to be used for interpreting input text (or generating output text) when the Content-Type header does not include one.
  ContextName | Utility class to manage context names so there is one place where the conversions between baseName, path and version take place.
  CustomObjectInputStream | Custom subclass of `ObjectInputStream` that loads from the class loader for this web application.
  DOMWriter | A DOM writer optimised for use by WebDAV.
  ErrorPageSupport | Provides support for tracking per exception type and per HTTP status code error pages.
  Introspection | Provides introspection utilities that either require knowledge of Tomcat internals or are solely used by Tomcat internals.
  IOTools | Contains commonly needed I/O-related methods
  LifecycleBase | Base implementation of the `Lifecycle` interface that implements the state transition rules for `Lifecycle.start()` and `Lifecycle.stop()`
  LifecycleMBeanBase |
  NetMask | A class representing a CIDR netmask.
  NetMaskSet | This class maintains a Set of NetMask objects and allows to check if a given IP address is matched by any of the NetMasks, making it easy to create Allow and Deny lists of CIDR networks and hosts.
  ParameterMap<K,​V> | Implementation of java.util.Map that includes a `locked` property.
  RequestUtil | General purpose request parsing and encoding utility methods.
  ResourceSet<T> | Extended implementation of HashSet that includes a `locked` property.
  ServerInfo | Simple utility module to make it easy to plug in the server identifier when integrating Tomcat.
  SessionConfig |
  SessionIdGeneratorBase |
  StandardSessionIdGenerator |
  Strftime | Converts dates to strings using the same format specifiers as strftime Note: This does not mimic strftime perfectly.
  TimeBucketCounter | This class maintains a thread safe hash map that has timestamp-based buckets followed by a string for a key, and a counter for a value. each time the increment() method is called it adds the key if it does not exist, increments its value and returns it. a maintenance thread cleans up keys that are prefixed by previous timestamp buckets.
  TLSUtil |
  TomcatCSS |
  ToStringUtil | Utility class used to help generate return values for calls to `Object.toString()`.
  URLEncoder | This class is very similar to the java.net.URLEncoder class.
  XMLWriter | XMLWriter helper class.