001    /*
002     * Copyright 2004-2006 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.annotation;
020    
021    import java.lang.annotation.ElementType;
022    import java.lang.annotation.RetentionPolicy;
023    import java.lang.annotation.Retention;
024    import java.lang.annotation.Target;
025    
026    /**
027     * Component annotation dealing with lifestyle policy, lifecycle model, and collection semantics.
028     * @author <a href="http://www.dpml.net">Digital Product Management Library</a>
029     * @version 2.1.1
030     */
031     @Target( ElementType.TYPE )
032     @Retention( RetentionPolicy.RUNTIME )
033    public @interface Component
034    {
035       /**
036        * Declaration of the component name. QAs a general rule it is recommended
037        * that component names should be restricted to short names without periods or
038        * spaces (such as 'widget', 'gizmo', etc.).  Component names are used in the 
039        * construction of composite names that fully qualify the component within the 
040        * runtime and serve as logging category names.  If undefined, a "" name value
041        * is declared in which case a container may resolve a name based on the component
042        * classname.
043        */
044        String name() default "";
045        
046       /**
047        * Declaration of an explicit component lifestyle policy.  If undefined the 
048        * default policy is LifestylePolicy.THREAD.
049        */
050        LifestylePolicy lifestyle() default LifestylePolicy.THREAD;
051        
052       /**
053        * Declaration of an explicit component collection policy.  If undefined the 
054        * default policy is CollectionPolicy.HARD.
055        */
056        CollectionPolicy collection() default CollectionPolicy.HARD;
057        
058       /**
059        * Declaration of an alternative lifestyle graph via a URI.  If undefined the 
060        * default semantics are derived from a graph definition colocated with the class
061        * using the resource path <classname>.xgraph.
062        */
063        String lifecycle() default "";
064        
065       /**
066        * Declaration of an alternative component runtime handler uri.
067        */
068        String handlerURI() default "link:part:dpml/metro/dpml-lang-component";
069        
070       /**
071        * Declaration of an alternative component runtime strategy handler classname.
072        */
073        String handlerClassname() default "net.dpml.runtime.ComponentStrategyHandler";
074    }