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.AccessibleObject; 020import java.lang.reflect.Field; 021import java.lang.reflect.InvocationTargetException; 022import java.lang.reflect.Type; 023import java.security.AccessController; 024import java.security.PrivilegedAction; 025import java.util.ArrayList; 026import java.util.List; 027import java.util.Set; 028 029/** 030 * Injection happens after instantiation, and through fields marked as injection points via an Annotation. 031 * The default annotation of org.picocontainer.annotations.@Inject can be overridden. 032 */ 033@SuppressWarnings("serial") 034public class AnnotatedFieldInjector<T> extends AbstractFieldInjector<T> { 035 036 private final Class<? extends Annotation> injectionAnnotation; 037 038 public AnnotatedFieldInjector(Object key, 039 Class<?> impl, 040 Parameter[] parameters, 041 ComponentMonitor componentMonitor, 042 Class<? extends Annotation> injectionAnnotation, boolean useNames) { 043 044 super(key, impl, parameters, componentMonitor, useNames); 045 this.injectionAnnotation = injectionAnnotation; 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 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 AccessController.doPrivileged(new PrivilegedAction<Field[]>() { 085 public Field[] run() { 086 return clazz.getDeclaredFields(); 087 } 088 }); 089 } 090 091 protected Object injectIntoMember(AccessibleObject member, Object componentInstance, Object toInject) 092 throws IllegalAccessException, InvocationTargetException { 093 Field field = (Field) member; 094 field.setAccessible(true); 095 field.set(componentInstance, toInject); 096 return null; 097 } 098 099 @Override 100 public String getDescriptor() { 101 return "AnnotatedFieldInjector-"; 102 } 103 104 @Override 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}