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 *****************************************************************************/ 008 009 package org.picocontainer.gems.constraints; 010 011 import org.picocontainer.ComponentAdapter; 012 import org.picocontainer.NameBinding; 013 import org.picocontainer.PicoContainer; 014 import org.picocontainer.PicoCompositionException; 015 import org.picocontainer.injectors.AbstractInjector; 016 import org.picocontainer.parameters.CollectionComponentParameter; 017 018 import java.lang.reflect.Array; 019 import java.lang.annotation.Annotation; 020 import java.util.Map; 021 022 /** 023 * Base class for parameter constraints. 024 * 025 * @author Nick Sieger 026 */ 027 public abstract class AbstractConstraint extends CollectionComponentParameter implements Constraint { 028 029 /** Construct an AbstractContraint. */ 030 protected AbstractConstraint() { 031 super(false); 032 } 033 034 @Override 035 public Object resolveInstance(final PicoContainer container, 036 final ComponentAdapter adapter, 037 final Class expectedType, 038 final NameBinding expectedNameBinding, final boolean useNames, final Annotation binding) throws PicoCompositionException 039 { 040 final Object[] array = 041 (Object[])super.resolveInstance(container, adapter, getArrayType(expectedType), expectedNameBinding, 042 useNames, null); 043 if (array.length == 1) { 044 return array[0]; 045 } 046 return null; 047 } 048 049 @Override 050 public boolean isResolvable(final PicoContainer container, 051 final ComponentAdapter adapter, 052 final Class expectedType, 053 final NameBinding expectedNameBinding, final boolean useNames, final Annotation binding) throws PicoCompositionException 054 { 055 return super.isResolvable(container, adapter, getArrayType(expectedType), expectedNameBinding, useNames, 056 binding); 057 } 058 059 @Override 060 public void verify(final PicoContainer container, 061 final ComponentAdapter adapter, 062 final Class expectedType, 063 final NameBinding expectedNameBinding, final boolean useNames, final Annotation binding) throws PicoCompositionException 064 { 065 super.verify(container, adapter, getArrayType(expectedType), expectedNameBinding, useNames, binding); 066 } 067 068 @Override 069 public abstract boolean evaluate(ComponentAdapter adapter); 070 071 @Override 072 protected Map<Object, ComponentAdapter<?>> getMatchingComponentAdapters(final PicoContainer container, 073 final ComponentAdapter adapter, 074 final Class keyType, 075 final Class valueType) 076 { 077 final Map<Object, ComponentAdapter<?>> map = 078 super.getMatchingComponentAdapters(container, adapter, keyType, valueType); 079 if (map.size() > 1) { 080 throw new AbstractInjector.AmbiguousComponentResolutionException(valueType, map.keySet().toArray(new Object[map.size()])); 081 } 082 return map; 083 } 084 085 private Class getArrayType(final Class expectedType) { 086 return Array.newInstance(expectedType, 0).getClass(); 087 } 088 }