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 *****************************************************************************/
010package org.picocontainer.injectors;
011
012import org.picocontainer.ComponentMonitor;
013import org.picocontainer.NameBinding;
014import org.picocontainer.Parameter;
015import org.picocontainer.PicoContainer;
016import org.picocontainer.annotations.Bind;
017
018import java.lang.annotation.Annotation;
019import java.lang.reflect.*;
020import java.security.AccessController;
021import java.security.PrivilegedAction;
022import java.util.ArrayList;
023import java.util.Arrays;
024import java.util.Collections;
025import java.util.List;
026import java.util.Set;
027
028/**
029 * Injection happens after instantiation, and fields are marked as
030 * injection points via a field type.
031 */
032@SuppressWarnings("serial")
033public class TypedFieldInjector<T> extends AbstractFieldInjector<T> {
034
035    private final List<String> classes;
036
037    public TypedFieldInjector(Object key,
038                                  Class<?> impl,
039                                  Parameter[] parameters,
040                                  ComponentMonitor componentMonitor,
041                                  String classNames) {
042        super(key, impl, parameters, componentMonitor, true);
043        this.classes = Arrays.asList(classNames.trim().split(" "));
044    }
045
046    @Override
047    protected void initializeInjectionMembersAndTypeLists() {
048        injectionMembers = new ArrayList<AccessibleObject>();
049        List<Annotation> bindingIds = new ArrayList<Annotation>();
050        final List<Type> typeList = new ArrayList<Type>();
051        final Field[] fields = getFields();
052        for (final Field field : fields) {
053            if (isTypedForInjection(field)) {
054                injectionMembers.add(field);
055                typeList.add(box(field.getType()));
056                bindingIds.add(getBinding(field));
057            }
058        }
059        injectionTypes = typeList.toArray(new Type[0]);
060        bindings = bindingIds.toArray(new Annotation[0]);
061    }
062
063    private Annotation getBinding(Field field) {
064        Annotation[] annotations = field.getAnnotations();
065        for (Annotation annotation : annotations) {
066            if (annotation.annotationType().isAnnotationPresent(Bind.class)) {
067                return annotation;
068            }
069        }
070        return null;
071    }
072
073    protected boolean isTypedForInjection(Field field) {
074        return classes.contains(field.getType().getName());
075    }
076
077    private Field[] getFields() {
078        return AccessController.doPrivileged(new PrivilegedAction<Field[]>() {
079            public Field[] run() {
080                return getComponentImplementation().getDeclaredFields();
081            }
082        });
083    }
084
085
086    protected Object injectIntoMember(AccessibleObject member, Object componentInstance, Object toInject)
087        throws IllegalAccessException, InvocationTargetException {
088        Field field = (Field) member;
089        field.setAccessible(true);
090        field.set(componentInstance, toInject);
091        return null;
092    }
093
094    @Override
095    public String getDescriptor() {
096        return "TypedFieldInjector-";
097    }
098
099    @Override
100    protected NameBinding makeParameterNameImpl(final AccessibleObject member) {
101        return new NameBinding() {
102            public String getName() {
103                return ((Field) member).getName();
104            }
105        };
106    }
107
108    protected Object memberInvocationReturn(Object lastReturn, AccessibleObject member, Object instance) {
109        return instance;
110    }
111
112    List<String> getInjectionFieldTypes() {
113        return Collections.unmodifiableList(classes);
114    }
115
116
117}