org.apache.catalina.core
Class StandardPipeline

java.lang.Object
  |
  +--org.apache.catalina.core.StandardPipeline
All Implemented Interfaces:
Contained, Lifecycle, Pipeline, ValveContext

public class StandardPipeline
extends java.lang.Object
implements Pipeline, Contained, Lifecycle, ValveContext

Standard implementation of a processing Pipeline that will invoke a series of Valves that have been configured to be called in order. This implementation can be used for any type of Container. IMPLEMENTATION WARNING - This implementation assumes that no calls to addValve() or removeValve are allowed while a request is currently being processed. Otherwise, the mechanism by which per-thread state is maintained will need to be modified.

Author:
Craig R. McClanahan

Field Summary
protected  Valve basic
          The basic Valve (if any) associated with this Pipeline.
protected  Container container
          The Container with which this Pipeline is associated.
protected  int debug
          The debugging detail level for this component.
protected  java.lang.String info
          Descriptive information about this implementation.
protected  LifecycleSupport lifecycle
          The lifecycle event support for this component.
protected static StringManager sm
          The string manager for this package.
protected  boolean started
          Has this component been started yet?
protected  java.lang.ThreadLocal state
          The per-thread execution state for processing through this pipeline.
protected  Valve[] valves
          The set of Valves (not including the Basic one, if any) associated with this Pipeline.
 
Fields inherited from interface org.apache.catalina.Lifecycle
START_EVENT, STOP_EVENT
 
Constructor Summary
StandardPipeline()
          Construct a new StandardPipeline instance with no associated Container.
StandardPipeline(Container container)
          Construct a new StandardPipeline instance that is associated with the specified Container.
 
Method Summary
 void addLifecycleListener(LifecycleListener listener)
          Add a lifecycle event listener to this component.
 void addValve(Valve valve)
          Add a new Valve to the end of the pipeline associated with this Container.
 Valve getBasic()
          Return the Valve instance that has been distinguished as the basic Valve for this Pipeline (if any).
 Container getContainer()
          Return the Container with which this Pipeline is associated.
 java.lang.String getInfo()
          Return descriptive information about this implementation class.
 Valve[] getValves()
          Return the set of Valves in the pipeline associated with this Container, including the basic Valve (if any).
 void invoke(Request request, Response response)
          Cause the specified request and response to be processed by the Valves associated with this pipeline, until one of these valves causes the response to be created and returned.
 void invokeNext(Request request, Response response)
          Cause the invoke() method of the next Valve that is part of the Pipeline currently being processed (if any) to be executed, passing on the specified request and response objects plus this ValveContext instance.
protected  void log(java.lang.String message)
          Log a message on the Logger associated with our Container (if any).
protected  void log(java.lang.String message, java.lang.Throwable throwable)
          Log a message on the Logger associated with our Container (if any).
 void removeLifecycleListener(LifecycleListener listener)
          Remove a lifecycle event listener from this component.
 void removeValve(Valve valve)
          Remove the specified Valve from the pipeline associated with this Container, if it is found; otherwise, do nothing.
 void setBasic(Valve valve)
          Set the Valve instance that has been distinguished as the basic Valve for this Pipeline (if any).
 void setContainer(Container container)
          Set the Container with which this Pipeline is associated.
 void start()
          Prepare for active use of the public methods of this Component.
 void stop()
          Gracefully shut down active use of the public methods of this Component.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

basic

protected Valve basic
The basic Valve (if any) associated with this Pipeline.


container

protected Container container
The Container with which this Pipeline is associated.


debug

protected int debug
The debugging detail level for this component.


info

protected java.lang.String info
Descriptive information about this implementation.


lifecycle

protected LifecycleSupport lifecycle
The lifecycle event support for this component.


sm

protected static StringManager sm
The string manager for this package.


started

protected boolean started
Has this component been started yet?


state

protected java.lang.ThreadLocal state
The per-thread execution state for processing through this pipeline. The actual value is a java.lang.Integer object containing the subscript into the values array, or a subscript equal to values.length if the basic Valve is currently being processed.


valves

protected Valve[] valves
The set of Valves (not including the Basic one, if any) associated with this Pipeline.

Constructor Detail

StandardPipeline

public StandardPipeline()
Construct a new StandardPipeline instance with no associated Container.


StandardPipeline

public StandardPipeline(Container container)
Construct a new StandardPipeline instance that is associated with the specified Container.

Parameters:
container - The container we should be associated with
Method Detail

getInfo

public java.lang.String getInfo()
Return descriptive information about this implementation class.

Specified by:
getInfo in interface ValveContext

getContainer

public Container getContainer()
Return the Container with which this Pipeline is associated.

Specified by:
getContainer in interface Contained

setContainer

public void setContainer(Container container)
Set the Container with which this Pipeline is associated.

Specified by:
setContainer in interface Contained
Parameters:
container - The new associated container

addLifecycleListener

public void addLifecycleListener(LifecycleListener listener)
Add a lifecycle event listener to this component.

Specified by:
addLifecycleListener in interface Lifecycle
Parameters:
listener - The listener to add

removeLifecycleListener

public void removeLifecycleListener(LifecycleListener listener)
Remove a lifecycle event listener from this component.

Specified by:
removeLifecycleListener in interface Lifecycle
Parameters:
listener - The listener to remove

start

public void start()
           throws LifecycleException
Prepare for active use of the public methods of this Component.

Specified by:
start in interface Lifecycle
Throws:
java.lang.IllegalStateException - if this component has already been started
LifecycleException - if this component detects a fatal error that prevents it from being started

stop

public void stop()
          throws LifecycleException
Gracefully shut down active use of the public methods of this Component.

Specified by:
stop in interface Lifecycle
Throws:
java.lang.IllegalStateException - if this component has not been started
LifecycleException - if this component detects a fatal error that needs to be reported

getBasic

public Valve getBasic()

Return the Valve instance that has been distinguished as the basic Valve for this Pipeline (if any).

Specified by:
getBasic in interface Pipeline

setBasic

public void setBasic(Valve valve)

Set the Valve instance that has been distinguished as the basic Valve for this Pipeline (if any). Prioer to setting the basic Valve, the Valve's setContainer() will be called, if it implements Contained, with the owning Container as an argument. The method may throw an IllegalArgumentException if this Valve chooses not to be associated with this Container, or IllegalStateException if it is already associated with a different Container.

Specified by:
setBasic in interface Pipeline
Parameters:
valve - Valve to be distinguished as the basic Valve

addValve

public void addValve(Valve valve)

Add a new Valve to the end of the pipeline associated with this Container. Prior to adding the Valve, the Valve's setContainer() method will be called, if it implements Contained, with the owning Container as an argument. The method may throw an IllegalArgumentException if this Valve chooses not to be associated with this Container, or IllegalStateException if it is already associated with a different Container.

Specified by:
addValve in interface Pipeline
Parameters:
valve - Valve to be added
Throws:
java.lang.IllegalArgumentException - if this Container refused to accept the specified Valve
java.lang.IllegalArgumentException - if the specifie Valve refuses to be associated with this Container
java.lang.IllegalStateException - if the specified Valve is already associated with a different Container

getValves

public Valve[] getValves()
Return the set of Valves in the pipeline associated with this Container, including the basic Valve (if any). If there are no such Valves, a zero-length array is returned.

Specified by:
getValves in interface Pipeline

invoke

public void invoke(Request request,
                   Response response)
            throws java.io.IOException,
                   javax.servlet.ServletException
Cause the specified request and response to be processed by the Valves associated with this pipeline, until one of these valves causes the response to be created and returned. The implementation must ensure that multiple simultaneous requests (on different threads) can be processed through the same Pipeline without interfering with each other's control flow.

Specified by:
invoke in interface Pipeline
Parameters:
request - The servlet request we are processing
response - The servlet response we are creating
Throws:
java.io.IOException - if an input/output error occurs
javax.servlet.ServletException - if a servlet exception is thrown

removeValve

public void removeValve(Valve valve)
Remove the specified Valve from the pipeline associated with this Container, if it is found; otherwise, do nothing. If the Valve is found and removed, the Valve's setContainer(null) method will be called if it implements Contained.

Specified by:
removeValve in interface Pipeline
Parameters:
valve - Valve to be removed

invokeNext

public void invokeNext(Request request,
                       Response response)
                throws java.io.IOException,
                       javax.servlet.ServletException
Cause the invoke() method of the next Valve that is part of the Pipeline currently being processed (if any) to be executed, passing on the specified request and response objects plus this ValveContext instance. Exceptions thrown by a subsequently executed Valve (or a Filter or Servlet at the application level) will be passed on to our caller. If there are no more Valves to be executed, an appropriate ServletException will be thrown by this ValveContext.

Specified by:
invokeNext in interface ValveContext
Parameters:
request - The request currently being processed
response - The response currently being created
Throws:
java.io.IOException - if thrown by a subsequent Valve, Filter, or Servlet
javax.servlet.ServletException - if thrown by a subsequent Valve, Filter, or Servlet
javax.servlet.ServletException - if there are no further Valves configured in the Pipeline currently being processed

log

protected void log(java.lang.String message)
Log a message on the Logger associated with our Container (if any).

Parameters:
message - Message to be logged

log

protected void log(java.lang.String message,
                   java.lang.Throwable throwable)
Log a message on the Logger associated with our Container (if any).

Parameters:
message - Message to be logged
throwable - Associated exception


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