org.rapidcontext.core.proc

Class Interceptor

java.lang.Object

org.rapidcontext.core.proc.Interceptor

Direct Known Subclasses:

DefaultInterceptor, JsCompileInterceptor

public abstract class Interceptor
extends java.lang.Object

A procedure call interceptor. This is an abstract class that allows subclasses to override, monitor or extend any resource reservation or procedure call in the library. Interceptors are chained together, and by default each interceptor delegates calls to its parent interceptor. A default interceptor is available that provides a standard implementation for all methods (necessary since it is the last link in the interceptor chain).

Version:

1.0

Author:

Per Cederberg, Dynabyte AB

See Also:

DefaultInterceptor

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Interceptor(Interceptor parent) Creates a new interceptor and links it to the specified parent interceptor.

Method Summary

Modifier and Type	Method and Description
java.lang.Object	call(CallContext cx, Procedure proc, Bindings bindings) Calls a procedure with the specified bindings.
Interceptor	getParent() Returns the parent interceptor in the interceptor chain.
void	releaseAll(CallContext cx, boolean commit) Releases all reserved adapter connections.
void	reserve(CallContext cx, Procedure proc) Reserves all adapter connections needed for executing the specified procedure.

Methods inherited from class java.lang.Object

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

Constructor Detail

Interceptor

protected Interceptor(Interceptor parent)

Creates a new interceptor and links it to the specified parent interceptor.

Parameters:

parent - the parent interceptor

Method Detail

getParent

public final Interceptor getParent()

Returns the parent interceptor in the interceptor chain.

Returns:

the parent interceptor, or null if no parent is available

reserve

public void reserve(CallContext cx,
                    Procedure proc)
             throws ProcedureException

Reserves all adapter connections needed for executing the specified procedure. All connections needed by imported procedures will also be reserved recursively.

Parameters:

cx - the procedure context

proc - the procedure definition

Throws:

ProcedureException - if the connections couldn't be reserved

releaseAll

public void releaseAll(CallContext cx,
                       boolean commit)

Releases all reserved adapter connections. The connections will either be committed or rolled back, depending on the commit flag.

Parameters:

cx - the procedure context

commit - the commit (or rollback) flag

call

public java.lang.Object call(CallContext cx,
                             Procedure proc,
                             Bindings bindings)
                      throws ProcedureException

Calls a procedure with the specified bindings.

Parameters:

cx - the procedure context

proc - the procedure definition

bindings - the procedure bindings

Returns:

the result of the call, or null if the call produced no result

Throws:

ProcedureException - if the call execution caused an error