001    /*
002     * JBoss, Home of Professional Open Source.
003     * Copyright 2008, Red Hat Middleware LLC, and individual contributors
004     * as indicated by the @author tags. See the copyright.txt file in the
005     * distribution for a full listing of individual contributors. 
006     *
007     * This is free software; you can redistribute it and/or modify it
008     * under the terms of the GNU Lesser General Public License as
009     * published by the Free Software Foundation; either version 2.1 of
010     * the License, or (at your option) any later version.
011     *
012     * This software is distributed in the hope that it will be useful,
013     * but WITHOUT ANY WARRANTY; without even the implied warranty of
014     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015     * Lesser General Public License for more details.
016     *
017     * You should have received a copy of the GNU Lesser General Public
018     * License along with this software; if not, write to the Free
019     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
020     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
021     */
022    package org.jboss.dna.graph;
023    
024    import java.security.AccessControlContext;
025    import javax.security.auth.Subject;
026    import javax.security.auth.login.LoginContext;
027    import org.jboss.dna.common.component.ClassLoaderFactory;
028    import org.jboss.dna.common.util.Logger;
029    import org.jboss.dna.graph.properties.NamespaceRegistry;
030    import org.jboss.dna.graph.properties.Property;
031    import org.jboss.dna.graph.properties.PropertyFactory;
032    import org.jboss.dna.graph.properties.ValueFactories;
033    
034    /**
035     * An ExecutionContext is a representation of the environment or context in which a component or operation is operating. Some
036     * components require this context to be passed into individual methods, allowing the context to vary with each method invocation.
037     * Other components require the context to be provided before it's used, and will use that context for all its operations (until
038     * it is given a different one).
039     * 
040     * @author Randall Hauch
041     * @author John Verhaeg
042     * @see ExecutionContextFactory
043     */
044    public interface ExecutionContext extends ClassLoaderFactory {
045    
046        /**
047         * @return the access control context; may be <code>null</code>
048         */
049        AccessControlContext getAccessControlContext();
050    
051        /**
052         * @return the login context; may be <code>null</code>
053         */
054        LoginContext getLoginContext();
055    
056        /**
057         * Get the factories that should be used to create values for {@link Property properties}.
058         * 
059         * @return the property value factory; never null
060         */
061        ValueFactories getValueFactories();
062    
063        /**
064         * Get the namespace registry for this context.
065         * 
066         * @return the namespace registry; never null
067         */
068        NamespaceRegistry getNamespaceRegistry();
069    
070        /**
071         * Get the factory for creating {@link Property} objects.
072         * 
073         * @return the property factory; never null
074         */
075        PropertyFactory getPropertyFactory();
076    
077        /**
078         * Get the JAAS subject for which this context was created.
079         * 
080         * @return the subject; never null
081         */
082        Subject getSubject();
083    
084        /**
085         * Return a logger associated with this context. This logger records only those activities within the context and provide a
086         * way to capture the context-specific activities. All log messages are also sent to the system logger, so classes that log
087         * via this mechanism should <i>not</i> also {@link Logger#getLogger(Class) obtain a system logger}.
088         * 
089         * @param clazz the class that is doing the logging
090         * @return the logger, named after <code>clazz</code>; never null
091         * @see #getLogger(String)
092         */
093        Logger getLogger( Class<?> clazz );
094    
095        /**
096         * Return a logger associated with this context. This logger records only those activities within the context and provide a
097         * way to capture the context-specific activities. All log messages are also sent to the system logger, so classes that log
098         * via this mechanism should <i>not</i> also {@link Logger#getLogger(Class) obtain a system logger}.
099         * 
100         * @param name the name for the logger
101         * @return the logger, named after <code>clazz</code>; never null
102         * @see #getLogger(Class)
103         */
104        Logger getLogger( String name );
105    }