# Class NullRealm

java.lang.Object
org.apache.catalina.util.LifecycleBase
org.apache.catalina.util.LifecycleMBeanBase
org.apache.catalina.realm.RealmBase
org.apache.catalina.realm.NullRealm

All Implemented Interfaces:
  `MBeanRegistration`, `Contained`, `JmxEnabled`, `Lifecycle`, `Realm`

public class NullRealm extends RealmBase
Minimal Realm implementation that always returns null when an attempt is made to validate a username and password. It is intended to be used as a default Realm implementation when no other Realm is specified.

- ## Nested Class Summary

  ### Nested classes/interfaces inherited from class org.apache.catalina.realm.RealmBase

  `RealmBase.AllRolesMode`

  ### Nested classes/interfaces inherited from interface org.apache.catalina.Lifecycle

  `Lifecycle.SingleUse`

- ## Field Summary

  ### Fields inherited from class org.apache.catalina.realm.RealmBase

  `allRolesMode, container, containerLog, realmPath, sm, stripRealmForGss, support, USER_ATTRIBUTES_DELIMITER, USER_ATTRIBUTES_WILDCARD, userAttributes, userAttributesList, validate, x509UsernameRetriever, x509UsernameRetrieverClassName`

  ### Fields inherited from interface org.apache.catalina.Lifecycle

  `AFTER_DESTROY_EVENT, AFTER_INIT_EVENT, AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_DESTROY_EVENT, BEFORE_INIT_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, CONFIGURE_START_EVENT, CONFIGURE_STOP_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `NullRealm()`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected String`
  `getPassword(String username)`
  Get the password for the specified user.
  `protected Principal`
  `getPrincipal(String username)`
  Get the principal associated with the specified user.

  ### Methods inherited from class org.apache.catalina.realm.RealmBase

  `addPropertyChangeListener, authenticate, authenticate, authenticate, authenticate, authenticate, authenticate, backgroundProcess, findSecurityConstraints, getAllRolesMode, getContainer, getCredentialHandler, getDigest, getDomainInternal, getObjectNameKeyProperties, getPrincipal, getPrincipal, getPrincipal, getRealmPath, getRealmSuffix, getServer, getTransportGuaranteeRedirectStatus, getUserAttributes, getValidate, getX509UsernameRetrieverClassName, hasMessageDigest, hasResourcePermission, hasRole, hasRoleInternal, hasUserDataPermission, initInternal, isStripRealmForGss, main, parseUserAttributes, removePropertyChangeListener, setAllRolesMode, setContainer, setCredentialHandler, setRealmPath, setStripRealmForGss, setTransportGuaranteeRedirectStatus, setUserAttributes, setValidate, setX509UsernameRetrieverClassName, startInternal, stopInternal, toString`

  ### Methods inherited from class org.apache.catalina.util.LifecycleMBeanBase

  `destroyInternal, getDomain, getObjectName, postDeregister, postRegister, preDeregister, preRegister, register, setDomain, unregister, unregister`

  ### Methods inherited from class org.apache.catalina.util.LifecycleBase

  `addLifecycleListener, destroy, findLifecycleListeners, fireLifecycleEvent, getState, getStateName, getThrowOnFailure, init, removeLifecycleListener, setState, setState, setThrowOnFailure, start, stop`

  ### Methods inherited from class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

  ### Methods inherited from interface org.apache.catalina.Realm

  `isAvailable`

- ## Constructor Details

  - ### NullRealm

    public NullRealm()

- ## Method Details

  - ### getPassword

    protected String getPassword(String username)
    Description copied from class: `RealmBase`
    Get the password for the specified user.
    Specified by:
      `getPassword` in class `RealmBase`
    Parameters:
      `username` - The username
    Returns:
      the password associated with the given principal's username.

  - ### getPrincipal

    protected Principal getPrincipal(String username)
    Description copied from class: `RealmBase`
    Get the principal associated with the specified user.
    Specified by:
      `getPrincipal` in class `RealmBase`
    Parameters:
      `username` - The username
    Returns:
      the Principal associated with the given username.