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