/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
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*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.aop.advice;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.WeakHashMap;
import org.jboss.aop.Advisor;
import org.jboss.aop.AspectManager;
import org.jboss.aop.Domain;
import org.jboss.aop.pointcut.Pointcut;
import org.jboss.aop.pointcut.PointcutExpression;
import org.jboss.aop.pointcut.ast.ASTCFlowExpression;
import org.jboss.aop.pointcut.ast.ParseException;
import org.jboss.aop.pointcut.ast.PointcutExpressionParser;
import org.jboss.logging.Logger;
/**
* Binds a pointcut expression to one ore more advices/interceptors.
*
* @author <a href="mailto:bill@jboss.org">Bill Burke</a>
* @version $Revision: 101146 $
* @see AspectManager#addBinding(AdviceBinding)
* @see AspectManager#removeBinding(String)
*/
public class AdviceBinding
{
private static final Logger logger = Logger.getLogger(AdviceBinding.class);
private static volatile long counter = 0;
/**
* Name that identifies this binding in its {@link Domain domain}.
*/
protected String name;
/**
* Identifies when the advices/interceptors contained in this binding should
* be invoked.
*/
protected Pointcut pointcut;
/**
* A control flow restriction (in its AST form). Can be {@code null}.
*/
protected ASTCFlowExpression cflow;
/**
* A control flow restriction (in its string form). Can be {@code null}
*/
protected String cflowString;
// not list because of redundancy caused by successive calls of ClassAdvisor.rebuildInterceptors
/**
* Contains all the client advisors, mapped to a boolean value.
*/
protected Map<Advisor, Boolean> advisors = new WeakHashMap<Advisor, Boolean>();
/**
* The factories responsible for creating the bound interceptor instances.
*/
protected InterceptorFactory[] interceptorFactories = new InterceptorFactory[0];
public AdviceBinding() {}
/**
* Constructor to be used internally.
*
* @param name identifies this definition in its {@link Domain domain}
* @param p pointcut expression. Only the joinpoints that satisfy
* this expression will be intercepted by the bound
* interceptors.
* @param cflow a control flow condition in the form of an {@code AST}
* parser
* @param cflowString a control flow expression
* @param factories creates the objects that will perform interception
* on the matched joinpoints
* @throws ParseException when {@code cflowString} is not {@code null} and
* contains a syntax error
*/
public AdviceBinding(String name, Pointcut p, ASTCFlowExpression cflow, String cflowString, InterceptorFactory[] factories) throws ParseException
{
this.name = name;
interceptorFactories = factories;
this.cflow = cflow;
pointcut = p;
this.cflowString = cflowString;
}
/**
* This constructor is used for creation of advice bindings programmatically on
* dynamic AOP operations.
* <p>
* The {@link #name name} of the advice will be generated automatically.
* <p>
* Bound interceptors will be invoked only on the joinpoints that are matched
* by {@code pointcutExpression}, and that satisfy {@code cflow} if it is not
* {@code null}.
*
* @param pointcutExpression pointcut expression. Only the joinpoints that satisfy
* this expression will be intercepted by the bound
* interceptors.
* @param cflow a control flow expression. Can be {@code null} if no
* such condition is necessary. Notice that using
* control flow conditions requires runtime checks and
* may impact your system performance. Always prefer to
* use pointcut expressions of the form {@code call(...)
* AND within(...)} or {@code call(...) AND
* withincode(...)} instead, whenever applicable.
* @throws ParseException when {@code cflow} is not {@code null} and contains a
* syntax error
*/
public AdviceBinding(String pointcutExpression, String cflow) throws ParseException
{
this(Long.toString(System.currentTimeMillis()) + ":" + Long.toString(counter++), pointcutExpression, cflow);
}
/**
* This constructor is used for creation of advice bindings programmatically on
* dynamic AOP operations. Call this constructor when you want to define the
* binding's name.
* <p>
* Bound interceptors will be invoked only on the joinpoints that are matched
* by {@code pointcutExpression}, and that satisfy {@code cflow} if it is not
* {@code null}.
*
* @param name identifies this binding in its {@link Domain domain}.
* @param pointcutExpression pointcut expression. Only the joinpoints that satisfy
* this expression can be intercepted by the bound
* interceptors.
* @param cflow a control flow expression. Can be {@code null} if no
* such condition is necessary. Notice that using
* control flow conditions requires runtime checks and
* may impact your system performance. Always prefer to
* use pointcut expressions of the form {@code call(...)
* AND within(...)} or {@code call(...) AND
* withincode(...)} instead, whenever applicable.
* @throws ParseException when {@code cflow} is not {@code null} and contains a
* syntax error
*/
public AdviceBinding(String name, String pointcutExpression, String cflow) throws ParseException
{
this.name = name;
setPointcutExpression(pointcutExpression);
setCFlowExpression(cflow);
interceptorFactories = new InterceptorFactory[0];
}
/**
* Defines a control-flow restriction to this binding.
* <br>
* Bound interceptors will not be invoked when this restriction is not satisfied.
* <br>
* Notice that using control flow conditions requires runtime checks and may
* impact your system performance. Always prefer to use pointcut expressions of
* the form {@code call(...) AND within(...)} or {@code call(...) AND
* withincode(...)} instead, whenever applicable.
*
* @param cflow a control flow expression.
* @throws ParseException when {@code cflow} is not {@code null} and contains a
* syntax error
*/
public void setCFlowExpression(String cflow)
throws ParseException
{
if (cflow != null)
{
cflowString = cflow;
this.cflow = new PointcutExpressionParser(new StringReader(cflowString)).CFlowExpression();
}
}
/**
* Defines the pointcut expression to be used by this binding.
* <br>
* Bound interceptors will be invoked only on the joinpoints that are matched
* by this expression, and that satisfy the {@code cflow} condition if there is
* one.
*
* @param pointcutExpression pointcut expression. Only the joinpoints that satisfy
* this expression can be intercepted by the bound
* interceptors.
* @throws ParseException when {@code cflow} is not {@code null} and contains a
* syntax error
*/
public void setPointcutExpression(String pointcutExpression)
throws ParseException
{
pointcut = new PointcutExpression(Long.toString(System.currentTimeMillis()) + ":" + Long.toString(counter++), pointcutExpression);
}
/**
* Adds an interceptor to the chain.
*
* @param factory creates the interceptor instances that will be invoked during
* interception
*/
public void addInterceptorFactory(InterceptorFactory factory)
{
List<InterceptorFactory> list = Arrays.asList(interceptorFactories);
list = new ArrayList<InterceptorFactory>(list);
list.add(factory);
interceptorFactories = list.toArray(new InterceptorFactory[list.size()]);
}
/**
* Adds an interceptor to the chain.
*
* @param clazz the actual class that implements {@link Interceptor}. This class
* must provide a default constructor so it can be created.
* A {@code GenericInterceptorFactory} will be used to create the
* interceptor instances.
* @see GenericInterceptorFactory
*/
public void addInterceptor(Class<?> clazz)
{
addInterceptorFactory(new GenericInterceptorFactory(clazz));
}
/**
* Returns the name of this binding. This name is unique inside the
* {@link Domain domain}.
*
* @return name the name that identifies this binding in its {@link Domain domain}
*/
public String getName()
{
return name;
}
/**
* Returns the interceptor factory chain.
* <p><i>For internal use only.</i>
*
* @return an array containing the interceptor factory chain. This chain will
* be used to create an equivalent chain (same order) of interceptor
* instances. The generated interceptor chain is the one that will
* be used on interception. This chain must not be edited this chain.
* @see #addInterceptor(Class)
* @see #addInterceptorFactory(InterceptorFactory)
*/
public InterceptorFactory[] getInterceptorFactories()
{
return interceptorFactories;
}
/**
* Defines the name of this binding. This name must be unique inside the
* {@link Domain domain}.
*
* @param name the name that identifies this binding in its {@link Domain domain}
*/
public void setName(String name)
{
this.name = name;
}
/**
* Returns the pointcut that determines when the bound interceptor chain should
* be invoked.
* <p><i>For internal use only.</i>
*
* @return the pointcut object
*/
public Pointcut getPointcut()
{
return pointcut;
}
/**
* Returns the cflow condition in the form an {@code AST} parser.
* <p><i>For internal use only.</i>
*
* @return the cflow condition that must be satisfied by joinpoints in order for
* the bound interceptors to be invoked
*/
public ASTCFlowExpression getCFlow()
{
return cflow;
}
/**
* Returns the cflow condition.
*
* @return the cflow condition expression that must be satisfied by joinpoints in
* order for the bound interceptors to be invoked
*/
public String getCFlowString()
{
return cflowString;
}
/**
* Adds an advisor as a client of this binding.
* <p>
* <i>For internal use only.</i>
*
* @param advisor manages one or more joinpoints that are matched by
* the bound {@link #pointcut}.
*/
public void addAdvisor(Advisor advisor)
{
if (AspectManager.verbose && logger.isDebugEnabled()) logger.debug("added advisor: " + advisor.getName() + " from binding: " + name);
// Don't hold a direct reference to an advisor because of undeploy and redeploy. Use WeakRefrences because
// we may be having in the future an Advisor per instance.
synchronized (advisors)
{
advisors.put(advisor, Boolean.TRUE);
}
}
/**
* Indicates whether there are any advisors using this binding for interception.
*
* @return {@code true} if and only if there are one or more advisors that use
* this binding for interception
*/
public boolean hasAdvisors()
{
return advisors.size() > 0;
}
/**
* Returns the list of the client advisors.
* <p>
* <i>For internal use only.</i>
*
* @return the list of the advisors that use this binding for interception
*/
public ArrayList<Advisor> getAdvisors()
{
ArrayList<Advisor> list = new ArrayList<Advisor>(advisors.size());
synchronized (advisors)
{
list.addAll(advisors.keySet());
}
return list;
}
/**
* Clears the list of the client advisors.
* <p>
* <i>For internal use only.</i>
*/
public void clearAdvisors()
{
synchronized (advisors)
{
for (Advisor advisor : advisors.keySet())
{
if (advisor.getManager().isAdvisorRegistered(advisor))
{
advisor.removeAdviceBinding(this);
}
}
advisors.clear();
}
}
/**
* Compares this binding with {@code obj} for equality.
*
* @param obj the object to be compared with this binding for equality
* @return {@code true} if and only if {@code obj} is a binding with a name that
* is equal to the name of this binding.
*/
public boolean equals(Object obj)
{
if (obj == this) return true;
if (!(obj instanceof AdviceBinding)) return false;
return ((AdviceBinding) obj).getName().equals(name);
}
public int hashCode()
{
return name.hashCode();
}
}