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 java.lang.annotation.Annotation; 013 import java.lang.reflect.AccessibleObject; 014 import java.lang.reflect.Field; 015 import java.lang.reflect.InvocationTargetException; 016 import java.security.AccessController; 017 import java.security.PrivilegedAction; 018 import java.util.ArrayList; 019 import java.util.Arrays; 020 import java.util.Collections; 021 import java.util.List; 022 023 import org.picocontainer.ComponentMonitor; 024 import org.picocontainer.LifecycleStrategy; 025 import org.picocontainer.NameBinding; 026 import org.picocontainer.Parameter; 027 import org.picocontainer.annotations.Bind; 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 { 035 036 037 private final List<String> fieldNames; 038 039 public NamedFieldInjector(Object key, 040 Class<?> impl, 041 Parameter[] parameters, 042 ComponentMonitor componentMonitor, 043 LifecycleStrategy lifecycleStrategy, 044 String fieldNames) { 045 046 super(key, impl, parameters, componentMonitor, lifecycleStrategy, true); 047 this.fieldNames = Arrays.asList(fieldNames.trim().split(" ")); 048 } 049 050 protected void initializeInjectionMembersAndTypeLists() { 051 injectionMembers = new ArrayList<AccessibleObject>(); 052 List<Annotation> bindingIds = new ArrayList<Annotation>(); 053 final List<Class> typeList = new ArrayList<Class>(); 054 final Field[] fields = getFields(); 055 for (final Field field : fields) { 056 if (isNamedForInjection(field)) { 057 injectionMembers.add(field); 058 typeList.add(box(field.getType())); 059 bindingIds.add(getBinding(field)); 060 } 061 } 062 injectionTypes = typeList.toArray(new Class[0]); 063 bindings = bindingIds.toArray(new Annotation[0]); 064 } 065 066 private Annotation getBinding(Field field) { 067 Annotation[] annotations = field.getAnnotations(); 068 for (Annotation annotation : annotations) { 069 if (annotation.annotationType().isAnnotationPresent(Bind.class)) { 070 return annotation; 071 } 072 } 073 return null; 074 } 075 076 protected boolean isNamedForInjection(Field field) { 077 return fieldNames.contains(field.getName()); 078 } 079 080 private Field[] getFields() { 081 return (Field[]) AccessController.doPrivileged(new PrivilegedAction() { 082 public Object run() { 083 return getComponentImplementation().getDeclaredFields(); 084 } 085 }); 086 } 087 088 089 protected void injectIntoMember(AccessibleObject member, Object componentInstance, Object toInject) 090 throws IllegalAccessException, InvocationTargetException { 091 Field field = (Field) member; 092 field.setAccessible(true); 093 field.set(componentInstance, toInject); 094 } 095 096 public String getDescriptor() { 097 return "NamedFieldInjector-"; 098 } 099 100 protected NameBinding makeParameterNameImpl(final AccessibleObject member) { 101 return new NameBinding() { 102 public String getName() { 103 return ((Field) member).getName(); 104 } 105 }; 106 } 107 108 List<String> getInjectionFieldNames() { 109 return Collections.unmodifiableList(fieldNames); 110 } 111 112 113 }