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