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 * Original code by *
009 *****************************************************************************/
010 package org.picocontainer.adapters;
011
012 import org.picocontainer.Behavior;
013 import org.picocontainer.PicoContainer;
014 import org.picocontainer.LifecycleStrategy;
015 import org.picocontainer.ComponentMonitor;
016 import org.picocontainer.PicoCompositionException;
017 import org.picocontainer.adapters.AbstractAdapter;
018 import org.picocontainer.lifecycle.NullLifecycleStrategy;
019 import org.picocontainer.monitors.NullComponentMonitor;
020
021 import java.lang.reflect.Type;
022
023 /**
024 * <p>
025 * Component adapter which wraps a component instance.
026 * </p>
027 * <p>
028 * This component adapter supports both a {@link Behavior Behavior} and a
029 * {@link org.picocontainer.LifecycleStrategy LifecycleStrategy} to control the lifecycle of the component.
030 * The lifecycle manager methods simply delegate to the lifecycle strategy methods
031 * on the component instance.
032 * </p>
033 *
034 * @author Aslak Hellesøy
035 * @author Paul Hammant
036 * @author Mauro Talevi
037 */
038 @SuppressWarnings("serial")
039 public final class InstanceAdapter<T> extends AbstractAdapter<T> implements Behavior<T>, LifecycleStrategy {
040
041
042 /**
043 * The actual instance of the component.
044 */
045 private final T componentInstance;
046
047 /**
048 * Lifecycle Strategy for the component adpater.
049 */
050 private final LifecycleStrategy lifecycleStrategy;
051
052
053 public InstanceAdapter(Object componentKey, T componentInstance, LifecycleStrategy lifecycleStrategy, ComponentMonitor componentMonitor) throws PicoCompositionException {
054 super(componentKey, getInstanceClass(componentInstance), componentMonitor);
055 this.componentInstance = componentInstance;
056 this.lifecycleStrategy = lifecycleStrategy;
057 }
058
059 public InstanceAdapter(Object componentKey, T componentInstance) {
060 this(componentKey,componentInstance,new NullLifecycleStrategy(),new NullComponentMonitor());
061 }
062
063 public InstanceAdapter(Object componentKey, T componentInstance, LifecycleStrategy lifecycleStrategy) {
064 this(componentKey,componentInstance,lifecycleStrategy,new NullComponentMonitor());
065 }
066
067 public InstanceAdapter(Object componentKey, T componentInstance, ComponentMonitor componentMonitor) {
068 this(componentKey,componentInstance,new NullLifecycleStrategy(),componentMonitor);
069 }
070
071 private static Class getInstanceClass(Object componentInstance) {
072 if (componentInstance == null) {
073 throw new NullPointerException("componentInstance cannot be null");
074 }
075 return componentInstance.getClass();
076 }
077
078 public T getComponentInstance(PicoContainer container, Type into) {
079 return componentInstance;
080 }
081
082 public void verify(PicoContainer container) {
083 }
084
085 public String getDescriptor() {
086 return "Instance-";
087 }
088
089 public void start(PicoContainer container) {
090 start(componentInstance);
091 }
092
093 public void stop(PicoContainer container) {
094 stop(componentInstance);
095 }
096
097 public void dispose(PicoContainer container) {
098 dispose(componentInstance);
099 }
100
101 public boolean componentHasLifecycle() {
102 return hasLifecycle(componentInstance.getClass());
103 }
104
105 // ~~~~~~~~ LifecycleStrategy ~~~~~~~~
106
107 public void start(Object component) {
108 lifecycleStrategy.start(componentInstance);
109 }
110
111 public void stop(Object component) {
112 lifecycleStrategy.stop(componentInstance);
113 }
114
115 public void dispose(Object component) {
116 lifecycleStrategy.dispose(componentInstance);
117 }
118
119 public boolean hasLifecycle(Class type) {
120 return lifecycleStrategy.hasLifecycle(type);
121 }
122
123 }