Package org.apache.catalina.core

## Class StandardWrapper

- java.lang.Object
- - org.apache.catalina.util.LifecycleBase
  - - org.apache.catalina.util.LifecycleMBeanBase
    - - org.apache.catalina.core.ContainerBase
      - - org.apache.catalina.core.StandardWrapper

- All Implemented Interfaces:
    `ServletConfig`, `javax.management.MBeanRegistration`, `javax.management.NotificationBroadcaster`, `javax.management.NotificationEmitter`, `Container`, `JmxEnabled`, `Lifecycle`, `Wrapper`
  Direct Known Subclasses:
    `Tomcat.ExistingStandardWrapper`

      public class StandardWrapper
      extends ContainerBase
      implements ServletConfig, Wrapper, javax.management.NotificationEmitter

  Standard implementation of the Wrapper interface that represents an individual servlet definition. No child Containers are allowed, and the parent Container must be a Context.
  Author:
    Craig R. McClanahan, Remy Maucherat

- - ### Nested Class Summary

    - ### Nested classes/interfaces inherited from class org.apache.catalina.core.ContainerBase

      `ContainerBase.ContainerBackgroundProcessor, ContainerBase.ContainerBackgroundProcessorMonitor, ContainerBase.PrivilegedAddChild`

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

      `Lifecycle.SingleUse`

  - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `protected boolean` | `asyncSupported` | Async support
    `protected long` | `available` | The date and time at which this servlet will become available (in milliseconds since the epoch), or zero if the servlet is available.
    `protected javax.management.NotificationBroadcasterSupport` | `broadcaster` | The broadcaster that sends j2ee notifications.
    `protected int` | `classLoadTime` |
    `protected static java.lang.Class<?>[]` | `classType` | Static class array used when the SecurityManager is turned on and `Servlet.init` is invoked.
    `protected java.util.concurrent.atomic.AtomicInteger` | `countAllocated` | The count of allocations that are currently active (even if they are for the same instance, as will be true on a non-STM servlet).
    `protected static java.lang.String[]` | `DEFAULT_SERVLET_METHODS` |
    `protected boolean` | `enabled` | Enabled
    `protected StandardWrapperFacade` | `facade` | The facade associated with this wrapper.
    `protected Servlet` | `instance` | The (single) possibly uninitialized instance of this servlet.
    `protected boolean` | `instanceInitialized` | Flag that indicates if this instance has been initialized
    `protected java.util.Stack<Servlet>` | `instancePool` | Deprecated. This will be removed in Tomcat 10.1 onwards.
    `protected boolean` | `isJspServlet` | True if this StandardWrapper is for the JspServlet
    `protected javax.management.ObjectName` | `jspMonitorON` | The ObjectName of the JSP monitoring mbean
    `protected int` | `loadOnStartup` | The load-on-startup order value (negative value means load on first call) for this servlet.
    `protected long` | `loadTime` |
    `protected java.util.ArrayList<java.lang.String>` | `mappings` | Mappings associated with the wrapper.
    `protected int` | `maxInstances` | Deprecated. This will be removed in Tomcat 10.1 onwards.
    `protected MultipartConfigElement` | `multipartConfigElement` | Multipart config
    `protected int` | `nInstances` | Deprecated. This will be removed in Tomcat 10.1 onwards.
    `protected javax.management.MBeanNotificationInfo[]` | `notificationInfo` |
    `protected java.util.HashMap<java.lang.String,​java.lang.String>` | `parameters` | The initialization parameters for this servlet, keyed by parameter name.
    `protected java.util.HashMap<java.lang.String,​java.lang.String>` | `references` | The security role references for this servlet, keyed by role name used in the servlet.
    `protected java.lang.String` | `runAs` | The run-as identity for this servlet.
    `protected long` | `sequenceNumber` | The notification sequence number.
    `protected java.lang.String` | `servletClass` | The fully qualified servlet class name for this servlet.
    `protected boolean` | `singleThreadModel` | Deprecated. This will be removed in Tomcat 10.1 onwards.
    `protected boolean` | `swallowOutput` | Should we swallow System.out
    `protected org.apache.catalina.core.StandardWrapperValve` | `swValve` |
    `protected long` | `unloadDelay` | Wait time for servlet unload in ms.
    `protected boolean` | `unloading` | Are we unloading our servlet instance at the moment?

    - ### Fields inherited from class org.apache.catalina.core.ContainerBase

      `accessLog, backgroundProcessorDelay, backgroundProcessorFuture, children, cluster, listeners, logger, logName, monitorFuture, name, parent, parentClassLoader, pipeline, sm, startChildren, startStopExecutor, support`

    - ### Fields inherited from interface org.apache.catalina.Container

      `ADD_CHILD_EVENT, ADD_VALVE_EVENT, REMOVE_CHILD_EVENT, REMOVE_VALVE_EVENT`

    - ### 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`

    - ### Fields inherited from interface org.apache.catalina.Wrapper

      `ADD_MAPPING_EVENT, REMOVE_MAPPING_EVENT`

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `StandardWrapper()` | Create a new StandardWrapper component with the default basic Valve.

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `void` | `addChild​(Container child)` | Refuse to add a child Container, because Wrappers are the lowest level of the Container hierarchy.
    `void` | `addInitParameter​(java.lang.String name, java.lang.String value)` | Add a new servlet initialization parameter for this servlet.
    `void` | `addMapping​(java.lang.String mapping)` | Add a mapping associated with the Wrapper.
    `void` | `addNotificationListener​(javax.management.NotificationListener listener, javax.management.NotificationFilter filter, java.lang.Object object)` | Add a JMX-NotificationListener
    `void` | `addSecurityReference​(java.lang.String name, java.lang.String link)` | Add a new security role reference record to the set of records for this servlet.
    `Servlet` | `allocate()` | Allocate an initialized instance of this Servlet that is ready to have its `service()` method called.
    `void` | `backgroundProcess()` | Execute a periodic task, such as reloading, etc.
    `void` | `deallocate​(Servlet servlet)` | Return this previously allocated servlet to the pool of available instances.
    `java.lang.String` | `findInitParameter​(java.lang.String name)` | Return the value for the specified initialization parameter name, if any; otherwise return `null`.
    `java.lang.String[]` | `findInitParameters()` | Return the names of all defined initialization parameters for this servlet.
    `java.lang.String[]` | `findMappings()` | Return the mappings associated with this wrapper.
    `java.lang.String` | `findSecurityReference​(java.lang.String name)` | Return the security role link for the specified security role reference name, if any; otherwise return `null`.
    `java.lang.String[]` | `findSecurityReferences()` | Return the set of security role reference names associated with this servlet, if any; otherwise return a zero-length array.
    `protected java.lang.reflect.Method[]` | `getAllDeclaredMethods​(java.lang.Class<?> c)` |
    `long` | `getAvailable()` | Return the available date/time for this servlet, in milliseconds since the epoch.
    `int` | `getClassLoadTime()` |
    `int` | `getCountAllocated()` |
    `int` | `getErrorCount()` |
    `java.lang.String` | `getInitParameter​(java.lang.String name)` | Returns a `String` containing the value of the named initialization parameter, or `null` if the parameter does not exist.
    `java.util.Enumeration<java.lang.String>` | `getInitParameterNames()` | Returns the names of the servlet's initialization parameters as an `Enumeration` of `String` objects, or an empty `Enumeration` if the servlet has no initialization parameters.
    `int` | `getLoadOnStartup()` |
    `java.lang.String` | `getLoadOnStartupString()` |
    `long` | `getLoadTime()` |
    `int` | `getMaxInstances()` | Deprecated. This will be removed in Tomcat 10.1 onwards.
    `long` | `getMaxTime()` |
    `long` | `getMinTime()` |
    `MultipartConfigElement` | `getMultipartConfigElement()` |
    `javax.management.MBeanNotificationInfo[]` | `getNotificationInfo()` | Get JMX Broadcaster Info
    `protected java.lang.String` | `getObjectNameKeyProperties()` | Allow sub-classes to specify the key properties component of the `ObjectName` that will be used to register this component.
    `long` | `getProcessingTime()` |
    `int` | `getRequestCount()` |
    `static java.lang.Throwable` | `getRootCause​(ServletException e)` | Extract the root cause from a servlet exception.
    `java.lang.String` | `getRunAs()` |
    `Servlet` | `getServlet()` |
    `java.lang.String` | `getServletClass()` |
    `ServletContext` | `getServletContext()` | Returns a reference to the `ServletContext` in which the caller is executing.
    `java.lang.String[]` | `getServletMethods()` | Gets the names of the methods supported by the underlying servlet.
    `java.lang.String` | `getServletName()` | Returns the name of this servlet instance.
    `void` | `incrementErrorCount()` | Increment the error count used for monitoring.
    `boolean` | `isAsyncSupported()` | Does the associated Servlet support async processing?
    `boolean` | `isEnabled()` | Is the associated Servlet enabled?
    `boolean` | `isOverridable()` | Is the Servlet overridable by a ServletContainerInitializer?
    `java.lang.Boolean` | `isSingleThreadModel()` | Deprecated. This will be removed in Tomcat 10.1 onwards.
    `boolean` | `isUnavailable()` |
    `void` | `load()` | Load and initialize an instance of this servlet, if there is not already at least one initialized instance.
    `Servlet` | `loadServlet()` | Load and initialize an instance of this servlet, if there is not already at least one initialized instance.
    `void` | `removeInitParameter​(java.lang.String name)` | Remove the specified initialization parameter from this servlet.
    `void` | `removeMapping​(java.lang.String mapping)` | Remove a mapping associated with the wrapper.
    `void` | `removeNotificationListener​(javax.management.NotificationListener listener)` | Remove a JMX-NotificationListener
    `void` | `removeNotificationListener​(javax.management.NotificationListener listener, javax.management.NotificationFilter filter, java.lang.Object object)` | Remove a JMX notificationListener
    `void` | `removeSecurityReference​(java.lang.String name)` | Remove any security role reference for the specified role name.
    `void` | `setAsyncSupported​(boolean asyncSupported)` | Set the async support for the associated Servlet.
    `void` | `setAvailable​(long available)` | Set the available date/time for this servlet, in milliseconds since the epoch.
    `void` | `setEnabled​(boolean enabled)` | Sets the enabled attribute for the associated servlet.
    `void` | `setLoadOnStartup​(int value)` | Set the load-on-startup order value (negative value means load on first call).
    `void` | `setLoadOnStartupString​(java.lang.String value)` | Set the load-on-startup order value from a (possibly null) string.
    `void` | `setMaxInstances​(int maxInstances)` | Deprecated. This will be removed in Tomcat 10.1 onwards.
    `void` | `setMultipartConfigElement​(MultipartConfigElement multipartConfigElement)` | Set the multi-part configuration for the associated Servlet.
    `void` | `setOverridable​(boolean overridable)` | Sets the overridable attribute for this Servlet.
    `void` | `setParent​(Container container)` | Set the parent Container of this Wrapper, but only if it is a Context.
    `void` | `setRunAs​(java.lang.String runAs)` | Set the run-as identity for this servlet.
    `void` | `setServlet​(Servlet servlet)` | Set the associated servlet instance.
    `void` | `setServletClass​(java.lang.String servletClass)` | Set the fully qualified servlet class name for this servlet.
    `void` | `setServletName​(java.lang.String name)` | Set the name of this servlet.
    `protected void` | `startInternal()` | Start this component and implement the requirements of `LifecycleBase.startInternal()`.
    `protected void` | `stopInternal()` | Stop this component and implement the requirements of `LifecycleBase.stopInternal()`.
    `void` | `unavailable​(UnavailableException unavailable)` | Process an UnavailableException, marking this servlet as unavailable for the specified amount of time.
    `void` | `unload()` | Unload all initialized instances of this servlet, after calling the `destroy()` method for each instance.

    - ### Methods inherited from class org.apache.catalina.core.ContainerBase

      `addContainerListener, addPropertyChangeListener, addValve, destroyInternal, findChild, findChildren, findContainerListeners, fireContainerEvent, getAccessLog, getBackgroundProcessorDelay, getCatalinaBase, getCatalinaHome, getChildren, getCluster, getClusterInternal, getDomainInternal, getLogger, getLogName, getMBeanKeyProperties, getName, getParent, getParentClassLoader, getPipeline, getRealm, getRealmInternal, getStartChildren, getStartStopThreads, initInternal, logAccess, removeChild, removeContainerListener, removePropertyChangeListener, setBackgroundProcessorDelay, setCluster, setName, setParentClassLoader, setRealm, setStartChildren, setStartStopThreads, threadStart, threadStop, toString`

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

      `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.Container

      `addContainerListener, addPropertyChangeListener, findChild, findChildren, findContainerListeners, fireContainerEvent, getAccessLog, getBackgroundProcessorDelay, getCatalinaBase, getCatalinaHome, getCluster, getDomain, getLogger, getLogName, getMBeanKeyProperties, getName, getObjectName, getParent, getParentClassLoader, getPipeline, getRealm, getStartStopThreads, logAccess, removeChild, removeContainerListener, removePropertyChangeListener, setBackgroundProcessorDelay, setCluster, setName, setParentClassLoader, setRealm, setStartStopThreads`

    - ### Methods inherited from interface org.apache.catalina.Lifecycle

      `addLifecycleListener, destroy, findLifecycleListeners, getState, getStateName, init, removeLifecycleListener, start, stop`

- - ### Field Detail

    - #### DEFAULT_SERVLET_METHODS

          protected static final java.lang.String[] DEFAULT_SERVLET_METHODS

    - #### available

          protected long available

      The date and time at which this servlet will become available (in milliseconds since the epoch), or zero if the servlet is available. If this value equals Long.MAX_VALUE, the unavailability of this servlet is considered permanent.

    - #### broadcaster

          protected final javax.management.NotificationBroadcasterSupport broadcaster

      The broadcaster that sends j2ee notifications.

    - #### countAllocated

          protected final java.util.concurrent.atomic.AtomicInteger countAllocated

      The count of allocations that are currently active (even if they are for the same instance, as will be true on a non-STM servlet).

    - #### facade

          protected final StandardWrapperFacade facade

      The facade associated with this wrapper.

    - #### instance

          protected volatile Servlet instance

      The (single) possibly uninitialized instance of this servlet.

    - #### instanceInitialized

          protected volatile boolean instanceInitialized

      Flag that indicates if this instance has been initialized

    - #### loadOnStartup

          protected int loadOnStartup

      The load-on-startup order value (negative value means load on first call) for this servlet.

    - #### mappings

          protected final java.util.ArrayList<java.lang.String> mappings

      Mappings associated with the wrapper.

    - #### parameters

          protected java.util.HashMap<java.lang.String,​java.lang.String> parameters

      The initialization parameters for this servlet, keyed by parameter name.

    - #### references

          protected java.util.HashMap<java.lang.String,​java.lang.String> references

      The security role references for this servlet, keyed by role name used in the servlet. The corresponding value is the role name of the web application itself.

    - #### runAs

          protected java.lang.String runAs

      The run-as identity for this servlet.

    - #### sequenceNumber

          protected long sequenceNumber

      The notification sequence number.

    - #### servletClass

          protected java.lang.String servletClass

      The fully qualified servlet class name for this servlet.

    - #### singleThreadModel

          @Deprecated
          protected volatile boolean singleThreadModel

      Deprecated.
      This will be removed in Tomcat 10.1 onwards.
      Does this servlet implement the SingleThreadModel interface?

    - #### unloading

          protected volatile boolean unloading

      Are we unloading our servlet instance at the moment?

    - #### maxInstances

          @Deprecated
          protected int maxInstances

      Deprecated.
      This will be removed in Tomcat 10.1 onwards.
      Maximum number of STM instances.

    - #### nInstances

          @Deprecated
          protected int nInstances

      Deprecated.
      This will be removed in Tomcat 10.1 onwards.
      Number of instances currently loaded for a STM servlet.

    - #### instancePool

          @Deprecated
          protected java.util.Stack<Servlet> instancePool

      Deprecated.
      This will be removed in Tomcat 10.1 onwards.
      Stack containing the STM instances.

    - #### unloadDelay

          protected long unloadDelay

      Wait time for servlet unload in ms.

    - #### isJspServlet

          protected boolean isJspServlet

      True if this StandardWrapper is for the JspServlet

    - #### jspMonitorON

          protected javax.management.ObjectName jspMonitorON

      The ObjectName of the JSP monitoring mbean

    - #### swallowOutput

          protected boolean swallowOutput

      Should we swallow System.out

    - #### swValve

          protected org.apache.catalina.core.StandardWrapperValve swValve

    - #### loadTime

          protected long loadTime

    - #### classLoadTime

          protected int classLoadTime

    - #### multipartConfigElement

          protected MultipartConfigElement multipartConfigElement

      Multipart config

    - #### asyncSupported

          protected boolean asyncSupported

      Async support

    - #### enabled

          protected boolean enabled

      Enabled

    - #### classType

          protected static java.lang.Class<?>[] classType

      Static class array used when the SecurityManager is turned on and `Servlet.init` is invoked.

    - #### notificationInfo

          protected javax.management.MBeanNotificationInfo[] notificationInfo

  - ### Constructor Detail

    - #### StandardWrapper

          public StandardWrapper()

      Create a new StandardWrapper component with the default basic Valve.

  - ### Method Detail

    - #### isOverridable

          public boolean isOverridable()

      Description copied from interface: `Wrapper`
      Is the Servlet overridable by a ServletContainerInitializer?
      Specified by:
        `isOverridable` in interface `Wrapper`
      Returns:
        `true` if the Servlet can be overridden in a ServletContainerInitializer

    - #### setOverridable

          public void setOverridable​(boolean overridable)

      Description copied from interface: `Wrapper`
      Sets the overridable attribute for this Servlet.
      Specified by:
        `setOverridable` in interface `Wrapper`
      Parameters:
        `overridable` - the new value

    - #### getAvailable

          public long getAvailable()

      Return the available date/time for this servlet, in milliseconds since the epoch. If this date/time is Long.MAX_VALUE, it is considered to mean that unavailability is permanent and any request for this servlet will return an SC_NOT_FOUND error. If this date/time is in the future, any request for this servlet will return an SC_SERVICE_UNAVAILABLE error. If it is zero, the servlet is currently available.
      Specified by:
        `getAvailable` in interface `Wrapper`
      Returns:
        the available date/time for this servlet, in milliseconds since the epoch. If this date/time is in the future, any request for this servlet will return an SC_SERVICE_UNAVAILABLE error. If it is zero, the servlet is currently available. A value equal to Long.MAX_VALUE is considered to mean that unavailability is permanent.

    - #### setAvailable

          public void setAvailable​(long available)

      Set the available date/time for this servlet, in milliseconds since the epoch. If this date/time is Long.MAX_VALUE, it is considered to mean that unavailability is permanent and any request for this servlet will return an SC_NOT_FOUND error. If this date/time is in the future, any request for this servlet will return an SC_SERVICE_UNAVAILABLE error.
      Specified by:
        `setAvailable` in interface `Wrapper`
      Parameters:
        `available` - The new available date/time

    - #### getCountAllocated

          public int getCountAllocated()

      Returns:
        the number of active allocations of this servlet, even if they are all for the same instance (as will be true for servlets that do not implement `SingleThreadModel`.

    - #### getLoadOnStartup

          public int getLoadOnStartup()

      Specified by:
        `getLoadOnStartup` in interface `Wrapper`
      Returns:
        the load-on-startup order value (negative value means load on first call).

    - #### setLoadOnStartup

          public void setLoadOnStartup​(int value)

      Set the load-on-startup order value (negative value means load on first call).
      Specified by:
        `setLoadOnStartup` in interface `Wrapper`
      Parameters:
        `value` - New load-on-startup value

    - #### setLoadOnStartupString

          public void setLoadOnStartupString​(java.lang.String value)

      Set the load-on-startup order value from a (possibly null) string. Per the specification, any missing or non-numeric value is converted to a zero, so that this servlet will still be loaded at startup time, but in an arbitrary order.
      Parameters:
        `value` - New load-on-startup value

    - #### getLoadOnStartupString

          public java.lang.String getLoadOnStartupString()

      Returns:
        the load-on-startup value that was parsed

    - #### getMaxInstances

          @Deprecated
          public int getMaxInstances()

      Deprecated.
      This will be removed in Tomcat 10.1 onwards.
      Returns:
        maximum number of instances that will be allocated when a single thread model servlet is used.

    - #### setMaxInstances

          @Deprecated
          public void setMaxInstances​(int maxInstances)

      Deprecated.
      This will be removed in Tomcat 10.1 onwards.
      Set the maximum number of instances that will be allocated when a single thread model servlet is used.
      Parameters:
        `maxInstances` - New value of maxInstances

    - #### setParent

          public void setParent​(Container container)

      Set the parent Container of this Wrapper, but only if it is a Context.
      Specified by:
        `setParent` in interface `Container`
      Overrides:
        `setParent` in class `ContainerBase`
      Parameters:
        `container` - Proposed parent Container

    - #### getRunAs

          public java.lang.String getRunAs()

      Specified by:
        `getRunAs` in interface `Wrapper`
      Returns:
        the run-as identity for this servlet.

    - #### setRunAs

          public void setRunAs​(java.lang.String runAs)

      Set the run-as identity for this servlet.
      Specified by:
        `setRunAs` in interface `Wrapper`
      Parameters:
        `runAs` - New run-as identity value

    - #### getServletClass

          public java.lang.String getServletClass()

      Specified by:
        `getServletClass` in interface `Wrapper`
      Returns:
        the fully qualified servlet class name for this servlet.

    - #### setServletClass

          public void setServletClass​(java.lang.String servletClass)

      Set the fully qualified servlet class name for this servlet.
      Specified by:
        `setServletClass` in interface `Wrapper`
      Parameters:
        `servletClass` - Servlet class name

    - #### setServletName

          public void setServletName​(java.lang.String name)

      Set the name of this servlet. This is an alias for the normal `Container.setName()` method, and complements the `getServletName()` method required by the `ServletConfig` interface.
      Parameters:
        `name` - The new name of this servlet

    - #### isSingleThreadModel

          @Deprecated
          public java.lang.Boolean isSingleThreadModel()

      Deprecated.
      This will be removed in Tomcat 10.1 onwards.
      Does the servlet class represented by this component implement the `SingleThreadModel` interface? This can only be determined once the class is loaded. Calling this method will not trigger loading the class since that may cause the application to behave unexpectedly.
      Returns:
        `null` if the class has not been loaded, otherwise `true` if the servlet does implement `SingleThreadModel` and `false` if it does not.

    - #### isUnavailable

          public boolean isUnavailable()

      Specified by:
        `isUnavailable` in interface `Wrapper`
      Returns:
        `true` if the Servlet has been marked unavailable.

    - #### getServletMethods

          public java.lang.String[] getServletMethods()
                                               throws ServletException

      Description copied from interface: `Wrapper`
      Gets the names of the methods supported by the underlying servlet. This is the same set of methods included in the Allow response header in response to an OPTIONS request method processed by the underlying servlet.
      Specified by:
        `getServletMethods` in interface `Wrapper`
      Returns:
        Array of names of the methods supported by the underlying servlet
      Throws:
        `ServletException` - If the target servlet cannot be loaded

    - #### getServlet

          public Servlet getServlet()

      Specified by:
        `getServlet` in interface `Wrapper`
      Returns:
        the associated servlet instance.

    - #### setServlet

          public void setServlet​(Servlet servlet)

      Set the associated servlet instance.
      Specified by:
        `setServlet` in interface `Wrapper`
      Parameters:
        `servlet` - The associated Servlet

    - #### backgroundProcess

          public void backgroundProcess()

      Execute a periodic task, such as reloading, etc. This method will be invoked inside the classloading context of this container. Unexpected throwables will be caught and logged.
      Specified by:
        `backgroundProcess` in interface `Container`
      Overrides:
        `backgroundProcess` in class `ContainerBase`

    - #### getRootCause

          public static java.lang.Throwable getRootCause​(ServletException e)

      Extract the root cause from a servlet exception.
      Parameters:
        `e` - The servlet exception
      Returns:
        the root cause of the Servlet exception

    - #### addChild

          public void addChild​(Container child)

      Refuse to add a child Container, because Wrappers are the lowest level of the Container hierarchy.
      Specified by:
        `addChild` in interface `Container`
      Overrides:
        `addChild` in class `ContainerBase`
      Parameters:
        `child` - Child container to be added

    - #### addInitParameter

          public void addInitParameter​(java.lang.String name,
                                       java.lang.String value)

      Add a new servlet initialization parameter for this servlet.
      Specified by:
        `addInitParameter` in interface `Wrapper`
      Parameters:
        `name` - Name of this initialization parameter to add
        `value` - Value of this initialization parameter to add

    - #### addMapping

          public void addMapping​(java.lang.String mapping)

      Add a mapping associated with the Wrapper.
      Specified by:
        `addMapping` in interface `Wrapper`
      Parameters:
        `mapping` - The new wrapper mapping

    - #### addSecurityReference

          public void addSecurityReference​(java.lang.String name,
                                           java.lang.String link)

      Add a new security role reference record to the set of records for this servlet.
      Specified by:
        `addSecurityReference` in interface `Wrapper`
      Parameters:
        `name` - Role name used within this servlet
        `link` - Role name used within the web application

    - #### allocate

          public Servlet allocate()
                           throws ServletException

      Allocate an initialized instance of this Servlet that is ready to have its `service()` method called. If the servlet class does not implement `SingleThreadModel`, the (only) initialized instance may be returned immediately. If the servlet class implements `SingleThreadModel`, the Wrapper implementation must ensure that this instance is not allocated again until it is deallocated by a call to `deallocate()`.
      Specified by:
        `allocate` in interface `Wrapper`
      Returns:
        a new Servlet instance
      Throws:
        `ServletException` - if the servlet init() method threw an exception
        `ServletException` - if a loading error occurs

    - #### deallocate

          public void deallocate​(Servlet servlet)
                          throws ServletException

      Return this previously allocated servlet to the pool of available instances. If this servlet class does not implement SingleThreadModel, no action is actually required.
      Specified by:
        `deallocate` in interface `Wrapper`
      Parameters:
        `servlet` - The servlet to be returned
      Throws:
        `ServletException` - if a deallocation error occurs

    - #### findInitParameter

          public java.lang.String findInitParameter​(java.lang.String name)

      Return the value for the specified initialization parameter name, if any; otherwise return `null`.
      Specified by:
        `findInitParameter` in interface `Wrapper`
      Parameters:
        `name` - Name of the requested initialization parameter
      Returns:
        the value for the specified initialization parameter name, if any; otherwise return `null`.

    - #### findInitParameters

          public java.lang.String[] findInitParameters()

      Return the names of all defined initialization parameters for this servlet.
      Specified by:
        `findInitParameters` in interface `Wrapper`
      Returns:
        the names of all defined initialization parameters for this servlet.

    - #### findMappings

          public java.lang.String[] findMappings()

      Return the mappings associated with this wrapper.
      Specified by:
        `findMappings` in interface `Wrapper`
      Returns:
        the mappings associated with this wrapper.

    - #### findSecurityReference

          public java.lang.String findSecurityReference​(java.lang.String name)

      Return the security role link for the specified security role reference name, if any; otherwise return `null`.
      Specified by:
        `findSecurityReference` in interface `Wrapper`
      Parameters:
        `name` - Security role reference used within this servlet
      Returns:
        the security role link for the specified security role reference name, if any; otherwise return `null`.

    - #### findSecurityReferences

          public java.lang.String[] findSecurityReferences()

      Return the set of security role reference names associated with this servlet, if any; otherwise return a zero-length array.
      Specified by:
        `findSecurityReferences` in interface `Wrapper`
      Returns:
        the set of security role reference names associated with this servlet, if any; otherwise return a zero-length array.

    - #### load

          public void load()
                    throws ServletException

      Load and initialize an instance of this servlet, if there is not already at least one initialized instance. This can be used, for example, to load servlets that are marked in the deployment descriptor to be loaded at server startup time.

      IMPLEMENTATION NOTE: Servlets whose classnames begin with `org.apache.catalina.` (so-called "container" servlets) are loaded by the same classloader that loaded this class, rather than the classloader for the current web application. This gives such classes access to Catalina internals, which are prevented for classes loaded for web applications.

      Specified by:
        `load` in interface `Wrapper`
      Throws:
        `ServletException` - if the servlet init() method threw an exception
        `ServletException` - if some other loading problem occurs

    - #### loadServlet

          public Servlet loadServlet()
                              throws ServletException

      Load and initialize an instance of this servlet, if there is not already at least one initialized instance. This can be used, for example, to load servlets that are marked in the deployment descriptor to be loaded at server startup time.
      Returns:
        the loaded Servlet instance
      Throws:
        `ServletException` - for a Servlet load error

    - #### removeInitParameter

          public void removeInitParameter​(java.lang.String name)

      Remove the specified initialization parameter from this servlet.
      Specified by:
        `removeInitParameter` in interface `Wrapper`
      Parameters:
        `name` - Name of the initialization parameter to remove

    - #### removeMapping

          public void removeMapping​(java.lang.String mapping)

      Remove a mapping associated with the wrapper.
      Specified by:
        `removeMapping` in interface `Wrapper`
      Parameters:
        `mapping` - The pattern to remove

    - #### removeSecurityReference

          public void removeSecurityReference​(java.lang.String name)

      Remove any security role reference for the specified role name.
      Specified by:
        `removeSecurityReference` in interface `Wrapper`
      Parameters:
        `name` - Security role used within this servlet to be removed

    - #### unavailable

          public void unavailable​(UnavailableException unavailable)

      Process an UnavailableException, marking this servlet as unavailable for the specified amount of time.
      Specified by:
        `unavailable` in interface `Wrapper`
      Parameters:
        `unavailable` - The exception that occurred, or `null` to mark this servlet as permanently unavailable

    - #### unload

          public void unload()
                      throws ServletException

      Unload all initialized instances of this servlet, after calling the `destroy()` method for each instance. This can be used, for example, prior to shutting down the entire servlet engine, or prior to reloading all of the classes from the Loader associated with our Loader's repository.
      Specified by:
        `unload` in interface `Wrapper`
      Throws:
        `ServletException` - if an exception is thrown by the destroy() method

    - #### getInitParameter

          public java.lang.String getInitParameter​(java.lang.String name)

      Description copied from interface: `jakarta.servlet.ServletConfig`
      Returns a `String` containing the value of the named initialization parameter, or `null` if the parameter does not exist.
      Specified by:
        `getInitParameter` in interface `ServletConfig`
      Parameters:
        `name` - Name of the initialization parameter to retrieve
      Returns:
        the initialization parameter value for the specified name, if any; otherwise return `null`.

    - #### getInitParameterNames

          public java.util.Enumeration<java.lang.String> getInitParameterNames()

      Description copied from interface: `jakarta.servlet.ServletConfig`
      Returns the names of the servlet's initialization parameters as an `Enumeration` of `String` objects, or an empty `Enumeration` if the servlet has no initialization parameters.
      Specified by:
        `getInitParameterNames` in interface `ServletConfig`
      Returns:
        the set of initialization parameter names defined for this servlet. If none are defined, an empty Enumeration is returned.

    - #### getServletContext

          public ServletContext getServletContext()

      Description copied from interface: `jakarta.servlet.ServletConfig`
      Returns a reference to the `ServletContext` in which the caller is executing.
      Specified by:
        `getServletContext` in interface `ServletConfig`
      Returns:
        the servlet context with which this servlet is associated.
      See Also:
        `ServletContext`

    - #### getServletName

          public java.lang.String getServletName()

      Description copied from interface: `jakarta.servlet.ServletConfig`
      Returns the name of this servlet instance. The name may be provided via server administration, assigned in the web application deployment descriptor, or for an unregistered (and thus unnamed) servlet instance it will be the servlet's class name.
      Specified by:
        `getServletName` in interface `ServletConfig`
      Returns:
        the name of this servlet.

    - #### getProcessingTime

          public long getProcessingTime()

    - #### getMaxTime

          public long getMaxTime()

    - #### getMinTime

          public long getMinTime()

    - #### getRequestCount

          public int getRequestCount()

    - #### getErrorCount

          public int getErrorCount()

    - #### incrementErrorCount

          public void incrementErrorCount()

      Increment the error count used for monitoring.
      Specified by:
        `incrementErrorCount` in interface `Wrapper`

    - #### getLoadTime

          public long getLoadTime()

    - #### getClassLoadTime

          public int getClassLoadTime()

    - #### getMultipartConfigElement

          public MultipartConfigElement getMultipartConfigElement()

      Specified by:
        `getMultipartConfigElement` in interface `Wrapper`
      Returns:
        the multi-part configuration for the associated Servlet. If no multi-part configuration has been defined, then `null` will be returned.

    - #### setMultipartConfigElement

          public void setMultipartConfigElement​(MultipartConfigElement multipartConfigElement)

      Description copied from interface: `Wrapper`
      Set the multi-part configuration for the associated Servlet. To clear the multi-part configuration specify `null` as the new value.
      Specified by:
        `setMultipartConfigElement` in interface `Wrapper`
      Parameters:
        `multipartConfigElement` - The configuration associated with the Servlet

    - #### isAsyncSupported

          public boolean isAsyncSupported()

      Description copied from interface: `Wrapper`
      Does the associated Servlet support async processing? Defaults to `false`.
      Specified by:
        `isAsyncSupported` in interface `Wrapper`
      Returns:
        `true` if the Servlet supports async

    - #### setAsyncSupported

          public void setAsyncSupported​(boolean asyncSupported)

      Description copied from interface: `Wrapper`
      Set the async support for the associated Servlet.
      Specified by:
        `setAsyncSupported` in interface `Wrapper`
      Parameters:
        `asyncSupported` - the new value

    - #### isEnabled

          public boolean isEnabled()

      Description copied from interface: `Wrapper`
      Is the associated Servlet enabled? Defaults to `true`.
      Specified by:
        `isEnabled` in interface `Wrapper`
      Returns:
        `true` if the Servlet is enabled

    - #### setEnabled

          public void setEnabled​(boolean enabled)

      Description copied from interface: `Wrapper`
      Sets the enabled attribute for the associated servlet.
      Specified by:
        `setEnabled` in interface `Wrapper`
      Parameters:
        `enabled` - the new value

    - #### getAllDeclaredMethods

          protected java.lang.reflect.Method[] getAllDeclaredMethods​(java.lang.Class<?> c)

    - #### startInternal

          protected void startInternal()
                                throws LifecycleException

      Start this component and implement the requirements of `LifecycleBase.startInternal()`.
      Overrides:
        `startInternal` in class `ContainerBase`
      Throws:
        `LifecycleException` - if this component detects a fatal error that prevents this component from being used

    - #### stopInternal

          protected void stopInternal()
                               throws LifecycleException

      Stop this component and implement the requirements of `LifecycleBase.stopInternal()`.
      Overrides:
        `stopInternal` in class `ContainerBase`
      Throws:
        `LifecycleException` - if this component detects a fatal error that prevents this component from being used

    - #### getObjectNameKeyProperties

          protected java.lang.String getObjectNameKeyProperties()

      Description copied from class: `LifecycleMBeanBase`
      Allow sub-classes to specify the key properties component of the `ObjectName` that will be used to register this component.
      Specified by:
        `getObjectNameKeyProperties` in class `LifecycleMBeanBase`
      Returns:
        The string representation of the key properties component of the desired `ObjectName`

    - #### removeNotificationListener

          public void removeNotificationListener​(javax.management.NotificationListener listener,
                                                 javax.management.NotificationFilter filter,
                                                 java.lang.Object object)
                                          throws javax.management.ListenerNotFoundException

      Remove a JMX notificationListener
      Specified by:
        `removeNotificationListener` in interface `javax.management.NotificationEmitter`
      Throws:
        `javax.management.ListenerNotFoundException`
      See Also:
        `NotificationEmitter.removeNotificationListener(javax.management.NotificationListener, javax.management.NotificationFilter, java.lang.Object)`

    - #### getNotificationInfo

          public javax.management.MBeanNotificationInfo[] getNotificationInfo()

      Get JMX Broadcaster Info
      Specified by:
        `getNotificationInfo` in interface `javax.management.NotificationBroadcaster`
      See Also:
        `NotificationBroadcaster.getNotificationInfo()`

    - #### addNotificationListener

          public void addNotificationListener​(javax.management.NotificationListener listener,
                                              javax.management.NotificationFilter filter,
                                              java.lang.Object object)
                                       throws java.lang.IllegalArgumentException

      Add a JMX-NotificationListener
      Specified by:
        `addNotificationListener` in interface `javax.management.NotificationBroadcaster`
      Throws:
        `java.lang.IllegalArgumentException`
      See Also:
        `NotificationBroadcaster.addNotificationListener(javax.management.NotificationListener, javax.management.NotificationFilter, java.lang.Object)`

    - #### removeNotificationListener

          public void removeNotificationListener​(javax.management.NotificationListener listener)
                                          throws javax.management.ListenerNotFoundException

      Remove a JMX-NotificationListener
      Specified by:
        `removeNotificationListener` in interface `javax.management.NotificationBroadcaster`
      Throws:
        `javax.management.ListenerNotFoundException`
      See Also:
        `NotificationBroadcaster.removeNotificationListener(javax.management.NotificationListener)`