org.apache.tomcat.util.handler
Class TcHandler

java.lang.Object
  org.apache.tomcat.util.handler.TcHandler

public abstract class TcHandler

extends java.lang.Object

The lowest level component of Jk ( and hopefully Coyote ). Try to keep it minimal and flexible - add only if you _have_ to add. It is similar in concept and can implement/wrap tomcat3.3 Interceptor, tomcat4.0 Valve, axis Handler, tomcat3.3 Handler, apache2 Hooks etc. Both iterative (Interceptor, Hook ) and recursive ( Valve ) behavior are supported. Named TcHandler because Handler name is too overloaded. The interface allows both stateless and statefull implementations ( like Servlet ).

Author:

Costin Manolache

Field Summary

protected java.util.Hashtable	attributes
static int	ERROR
protected int	id
static int	LAST
protected java.lang.String	name
protected TcHandler	next
static int	OK

Constructor Summary

TcHandler()

Method Summary

void	destroy() Clean up and stop the handler.
java.lang.Object	getAttribute(java.lang.String name) Get an attribute.
int	getId()
java.lang.String	getName()
void	init() Should register the request types it can handle, same style as apache2.
abstract int	invoke(TcHandlerCtx tcCtx) The 'hook' method.
void	setAttribute(java.lang.String name, java.lang.Object value) Base implementation will just save all attributes.
void	setId(int id) Set the id of the worker.
void	setName(java.lang.String s) Set the name of the handler.
void	setNext(TcHandler h) Catalina-style "recursive" invocation.
void	start()
void	stop()

Methods inherited from class java.lang.Object

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

Field Detail

OK

public static final int OK

See Also:

Constant Field Values

LAST

public static final int LAST

See Also:

Constant Field Values

ERROR

public static final int ERROR

See Also:

Constant Field Values

attributes

protected java.util.Hashtable attributes

next

protected TcHandler next

name

protected java.lang.String name

id

protected int id

Constructor Detail

TcHandler

public TcHandler()

Method Detail

setName

public void setName(java.lang.String s)

Set the name of the handler. Will allways be called by worker env after creating the worker.

getName

public java.lang.String getName()

setId

public void setId(int id)

Set the id of the worker. It can be used for faster dispatch. Must be unique, managed by whoever creates the handlers.

getId

public int getId()

setNext

public void setNext(TcHandler h)

Catalina-style "recursive" invocation. A handler is required to call the next handler if set.

setAttribute

public void setAttribute(java.lang.String name,
                         java.lang.Object value)

Base implementation will just save all attributes. It is higly desirable to override this and allow runtime reconfiguration. XXX Should I make it abstract and force everyone to override ?

getAttribute

public java.lang.Object getAttribute(java.lang.String name)

Get an attribute. Override to allow runtime query ( attribute can be anything, including statistics, etc )

init

public void init()
          throws java.io.IOException

Should register the request types it can handle, same style as apache2.

Throws:

java.io.IOException

destroy

public void destroy()
             throws java.io.IOException

Clean up and stop the handler. Override if needed.

Throws:

java.io.IOException

start

public void start()
           throws java.io.IOException

Throws:

java.io.IOException

stop

public void stop()
          throws java.io.IOException

Throws:

java.io.IOException

invoke

public abstract int invoke(TcHandlerCtx tcCtx)
                    throws java.io.IOException

The 'hook' method. If a 'next' was set, invoke should call it ( recursive behavior, similar with valve ). The application using the handler can also iterate, using the same semantics with Interceptor or APR hooks.

Throws:

java.io.IOException