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.injectors;
011    
012    import java.lang.annotation.Annotation;
013    import java.lang.reflect.AccessibleObject;
014    import java.lang.reflect.Field;
015    import java.lang.reflect.InvocationTargetException;
016    import java.lang.reflect.Type;
017    import java.security.AccessController;
018    import java.security.PrivilegedAction;
019    import java.util.ArrayList;
020    import java.util.Arrays;
021    import java.util.Collections;
022    import java.util.List;
023    
024    import org.picocontainer.ComponentMonitor;
025    import org.picocontainer.LifecycleStrategy;
026    import org.picocontainer.NameBinding;
027    import org.picocontainer.Parameter;
028    import org.picocontainer.annotations.Bind;
029    
030    /**
031     * Injection happens after instantiation, and fields are marked as
032     * injection points via a field type.
033     */
034    @SuppressWarnings("serial")
035    public class TypedFieldInjector extends IterativeInjector {
036    
037        /**
038             * Serialization UUID.
039             */
040    
041        private final List<String> classes;
042    
043        public TypedFieldInjector(Object key,
044                                      Class<?> impl,
045                                      Parameter[] parameters,
046                                      ComponentMonitor componentMonitor,
047                                      LifecycleStrategy lifecycleStrategy,
048                                      String classNames) {
049    
050            super(key, impl, parameters, componentMonitor, lifecycleStrategy, true);
051            this.classes = Arrays.asList(classNames.trim().split(" "));
052        }
053    
054        protected void initializeInjectionMembersAndTypeLists() {
055            injectionMembers = new ArrayList<AccessibleObject>();
056            List<Annotation> bindingIds = new ArrayList<Annotation>();
057            final List<Type> typeList = new ArrayList<Type>();
058            final Field[] fields = getFields();
059            for (final Field field : fields) {
060                if (isTypedForInjection(field)) {
061                    injectionMembers.add(field);
062                    typeList.add(box(field.getType()));
063                    bindingIds.add(getBinding(field));
064                }
065            }
066            injectionTypes = typeList.toArray(new Type[0]);
067            bindings = bindingIds.toArray(new Annotation[0]);
068        }
069    
070        private Annotation getBinding(Field field) {
071            Annotation[] annotations = field.getAnnotations();
072            for (Annotation annotation : annotations) {
073                if (annotation.annotationType().isAnnotationPresent(Bind.class)) {
074                    return annotation;
075                }
076            }
077            return null;
078        }
079    
080        protected boolean isTypedForInjection(Field field) {
081            return classes.contains(field.getType().getName());
082        }
083    
084        private Field[] getFields() {
085            return (Field[]) AccessController.doPrivileged(new PrivilegedAction() {
086                public Object run() {
087                    return getComponentImplementation().getDeclaredFields();
088                }
089            });
090        }
091    
092    
093        protected Object injectIntoMember(AccessibleObject member, Object componentInstance, Object toInject)
094            throws IllegalAccessException, InvocationTargetException {
095            Field field = (Field) member;
096            field.setAccessible(true);
097            field.set(componentInstance, toInject);
098            return null;
099        }
100    
101        public String getDescriptor() {
102            return "TypedFieldInjector-";
103        }
104    
105        protected NameBinding makeParameterNameImpl(final AccessibleObject member) {
106            return new NameBinding() {
107                public String getName() {
108                    return ((Field) member).getName();
109                }
110            };
111        }
112    
113        protected Object memberInvocationReturn(Object lastReturn, AccessibleObject member, Object instance) {
114            return instance;
115        }
116    
117        List<String> getInjectionFieldTypes() {
118            return Collections.unmodifiableList(classes);
119        }
120    
121    
122    }