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