001    /*
002     * Copyright 2005 Stephen J. McConnell.
003     *
004     * Licensed  under the  Apache License,  Version 2.0  (the "License");
005     * you may not use  this file  except in  compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     *   http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed  under the  License is distributed on an "AS IS" BASIS,
012     * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
013     * implied.
014     *
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    
019    package net.dpml.lang;
020    
021    import java.util.Map;
022    
023    /**
024     * A object resolvable from primitive and symbolic arguments.
025     *
026     * @author <a href="http://www.dpml.net">Digital Product Meta Library</a>
027     * @version 1.1.0
028     */
029    public interface Value
030    {
031       /**
032        * Resolve an instance from the value using the context classloader.
033        * @return the resolved instance
034        * @exception Exception if error occurs during instance resolution
035        */
036        Object resolve() throws Exception;
037        
038       /**
039        * Resolve an instance from the value using a supplied context map. If any 
040        * target expressions in immediate or nested values contain a symbolic
041        * expression the value will be resolved using the supplied map.
042        *
043        * @param map the context map
044        * @return the resolved instance
045        * @exception Exception if error occurs during instance resolution
046        */
047        Object resolve( Map map ) throws Exception;
048    
049       /**
050        * Resolve an instance from the value using a supplied isolation policy. 
051        *
052        * @param isolate the isolation policy
053        * @return the resolved instance
054        * @exception Exception if error occurs during instance resolution
055        */
056        Object resolve( boolean isolate ) throws Exception;
057    
058       /**
059        * Resolve an instance from the value using a supplied context map. If any 
060        * target expressions in immediate or nested values contain a symbolic
061        * expression the value will be resolved using the supplied map.
062        *
063        * @param map the context map
064        * @param isolate the isolation policy
065        * @return the resolved instance
066        * @exception Exception if error occurs during instance resolution
067        */
068        Object resolve( Map map, boolean isolate ) throws Exception;
069    
070       /**
071        * Resolve an instance from the value using a supplied context map. If any 
072        * target expressions in immediate or nested values contain a symbolic
073        * expression the value will be resolved using the supplied map.
074        *
075        * @param classname the default classname
076        * @param map the context map
077        * @param isolate the isolation policy
078        * @return the resolved instance
079        * @exception Exception if error occurs during instance resolution
080        */
081        Object resolve( String classname, Map map, boolean isolate ) throws Exception;
082    
083    }