org.apache.commons.chain.impl
Class ChainBase

java.lang.Object
  org.apache.commons.chain.impl.ChainBase

All Implemented Interfaces:

Chain, Command

public class ChainBase
extends Object
implements Chain

Convenience base class for Chain implementations.

Version:

$Revision: 480477 $ $Date: 2006-11-29 08:34:52 +0000 (Wed, 29 Nov 2006) $

Author:

Craig R. McClanahan

Field Summary

protected Command[]	commands The list of Commands configured for this Chain, in the order in which they may delegate processing to the remainder of the Chain.
protected boolean	frozen Flag indicating whether the configuration of our commands list has been frozen by a call to the execute() method.

Fields inherited from interface org.apache.commons.chain.Command

CONTINUE_PROCESSING, PROCESSING_COMPLETE

Constructor Summary

ChainBase()
Construct a Chain with no configured Commands.

ChainBase(Collection commands)
Construct a Chain configured with the specified Commands.

ChainBase(Command command)
Construct a Chain configured with the specified Command.

ChainBase(Command[] commands)
Construct a Chain configured with the specified Commands.

Method Summary

void	addCommand(Command command) See the Chain JavaDoc.
boolean	execute(Context context) See the Chain JavaDoc.

Methods inherited from class java.lang.Object

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

Field Detail

commands

protected Command[] commands

The list of Commands configured for this Chain, in the order in which they may delegate processing to the remainder of the Chain.

frozen

protected boolean frozen

Flag indicating whether the configuration of our commands list has been frozen by a call to the execute() method.

Constructor Detail

ChainBase

public ChainBase()

Construct a Chain with no configured Commands.

ChainBase

public ChainBase(Command command)

Construct a Chain configured with the specified Command.

Parameters:

command - The Command to be configured

Throws:

IllegalArgumentException - if command is null

ChainBase

public ChainBase(Command[] commands)

Construct a Chain configured with the specified Commands.

Parameters:

commands - The Commands to be configured

Throws:

IllegalArgumentException - if commands, or one of the individual Command elements, is null

ChainBase

public ChainBase(Collection commands)

Construct a Chain configured with the specified Commands.

Parameters:

commands - The Commands to be configured

Throws:

IllegalArgumentException - if commands, or one of the individual Command elements, is null

Method Detail

addCommand

public void addCommand(Command command)

See the Chain JavaDoc.

Specified by:

addCommand in interface Chain

Parameters:

command - The Command to be added

Throws:

IllegalArgumentException - if command is null

IllegalStateException - if no further configuration is allowed

execute

public boolean execute(Context context)
                throws Exception

See the Chain JavaDoc.

Specified by:

execute in interface Chain

Specified by:

execute in interface Command

Parameters:

context - The Context to be processed by this Chain

Returns:

true if the processing of this Context has been completed, or false if the processing of this Context should be delegated to a subsequent Command in an enclosing Chain

Throws:

Exception - if thrown by one of the Commands in this Chain but not handled by a postprocess() method of a Filter

IllegalArgumentException - if context is null