001    /*****************************************************************************
002     * Copyright (C) PicoContainer Organization. All rights reserved.            *
003     * ------------------------------------------------------------------------- *
004     * The software in this package is published under the terms of the BSD      *
005     * style license a copy of which has been included with this distribution in *
006     * the LICENSE.txt file.                                                     *
007     *                                                                           *
008     *****************************************************************************/
009    package org.picocontainer.injectors;
010    
011    import java.lang.reflect.Type;
012    
013    import org.picocontainer.ComponentMonitor;
014    import org.picocontainer.Injector;
015    import org.picocontainer.LifecycleStrategy;
016    import org.picocontainer.Parameter;
017    import org.picocontainer.PicoCompositionException;
018    import org.picocontainer.PicoContainer;
019    import org.picocontainer.PicoVisitor;
020    import org.picocontainer.ComponentAdapter;
021    
022    @SuppressWarnings("serial")
023    public class CompositeInjector<T> extends AbstractInjector<T> {
024    
025        private final Injector<T>[] injectors;
026    
027        public CompositeInjector(Object componentKey, Class<?> componentImplementation, Parameter[] parameters, ComponentMonitor monitor, LifecycleStrategy lifecycleStrategy,
028                                 boolean useNames, Injector... injectors) {
029            super(componentKey, componentImplementation, parameters, monitor, lifecycleStrategy, useNames);
030            this.injectors = injectors;
031        }
032    
033    
034        public T getComponentInstance(PicoContainer container) throws PicoCompositionException {
035            return getComponentInstance(container, NOTHING.class);
036        }
037    
038        public T getComponentInstance(PicoContainer container, Type into) throws PicoCompositionException {
039            T instance = null;
040            for (int i = 0; i < injectors.length; i++) {
041                Injector<T> injector = injectors[i];
042                if (instance == null) {
043                    instance = injector.getComponentInstance(container, ComponentAdapter.NOTHING.class);
044                } else {
045                    injector.decorateComponentInstance(container, into, instance);
046                }
047            }
048            return (T) instance;
049        }
050    
051    
052        /**
053         * @return the object returned is the result of the last of the injectors delegated to
054         */
055        @Override
056        public Object decorateComponentInstance(PicoContainer container, Type into, T instance) {
057            Object result = null;
058            for (int i = 0; i < injectors.length; i++) {
059                result = injectors[i].decorateComponentInstance(container, into, instance);
060            }
061            return result;
062        }
063    
064        public void verify(PicoContainer container) throws PicoCompositionException {
065            for (int i = 0; i < injectors.length; i++) {
066                injectors[i].verify(container);
067            }
068        }
069    
070        public final void accept(PicoVisitor visitor) {
071            super.accept(visitor);
072            for (int i = 0; i < injectors.length; i++) {
073                injectors[i].accept(visitor);
074            }
075        }
076    
077        public String getDescriptor() {
078            return "CompositeInjector";
079        }
080    }