org.xcmis.search.content.interceptors
Class CommandInterceptor

java.lang.Object
  org.xcmis.search.content.interceptors.AbstractVisitor
      org.xcmis.search.content.interceptors.CommandInterceptor

All Implemented Interfaces:

Visitor, Startable

Direct Known Subclasses:

ContentReaderInterceptor, QueryableIndexStorage, QueryProcessorInterceptor

public class CommandInterceptor
extends AbstractVisitor
implements Startable

This is the base class for all interceptors to extend, and implements the Visitor interface allowing it to intercept invocations on VisitableCommands.

When writing interceptors, authors can either override a specific visitXXX() method or the more generic handleDefault(InvocationContext , VisitableCommand) which is the default behaviour of any visit method, as defined in AbstractVisitor.handleDefault(InvocationContext , VisitableCommand).

The preferred approach is to override the specific visitXXX() methods that are of interest rather than to override handleDefault(InvocationContext , VisitableCommand) and then write a series of if statements or a switch block, if command-specific behaviour is needed.

Constructor Summary

CommandInterceptor()

Method Summary

CommandInterceptor	getNext() Retrieves the next interceptor in the chain.
protected Object	handleDefault(InvocationContext ctx, VisitableCommand command) The default behaviour of the visitXXX methods, which is to ignore the call and pass the call up to the next interceptor in the chain.
boolean	hasNext()
Object	invokeNextInterceptor(InvocationContext ctx, VisitableCommand command) Invokes the next interceptor in the chain.
void	setNext(CommandInterceptor next) Sets the next interceptor in the chain to the interceptor passed in.
void	start()
void	stop()

Methods inherited from class org.xcmis.search.content.interceptors.AbstractVisitor

visitChildEntriesCommand, visitExecuteSelectorCommand, visitGetContentEntryCommand, visitGetUnfiledEntriesCommand, visitModifyIndexCommand, visitProcessQueryCommand

Methods inherited from class java.lang.Object

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

Constructor Detail

CommandInterceptor

public CommandInterceptor()

Method Detail

getNext

public CommandInterceptor getNext()

Retrieves the next interceptor in the chain.

Returns:

the next interceptor in the chain.

hasNext

public boolean hasNext()

Returns:

true if there is another interceptor in the chain after this; false otherwise.

setNext

public void setNext(CommandInterceptor next)

Sets the next interceptor in the chain to the interceptor passed in.

Parameters:

next - next interceptor in the chain.

invokeNextInterceptor

public Object invokeNextInterceptor(InvocationContext ctx,
                                    VisitableCommand command)
                             throws Throwable

Invokes the next interceptor in the chain. This is how interceptor implementations should pass a call up the chain to the next interceptor.

Parameters:

ctx - invocation context

command - command to pass up the chain.

Returns:

return value of the invocation

Throws:

Throwable - in the event of problems

handleDefault

protected Object handleDefault(InvocationContext ctx,
                               VisitableCommand command)
                        throws Throwable

The default behaviour of the visitXXX methods, which is to ignore the call and pass the call up to the next interceptor in the chain.

Overrides:

handleDefault in class AbstractVisitor

Parameters:

ctx - invocation context

command - command to invoke

Returns:

return value

Throws:

Throwable - in the event of problems

start

public void start()

Specified by:

start in interface Startable

See Also:

Startable.start()

stop

public void stop()

Specified by:

stop in interface Startable

See Also:

Startable.stop()