org.picocontainer.parameters.CollectionComponentParameter Maven / Gradle / Ivy
The newest version!
/*****************************************************************************
* Copyright (C) PicoContainer Organization. All rights reserved. *
* ------------------------------------------------------------------------- *
* The software in this package is published under the terms of the BSD *
* style license a copy of which has been included with this distribution in *
* the LICENSE.txt file. *
* *
* Original code by *
*****************************************************************************/
package org.picocontainer.parameters;
import java.io.Serializable;
import java.lang.annotation.Annotation;
import java.lang.reflect.Array;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import org.picocontainer.ComponentAdapter;
import org.picocontainer.NameBinding;
import org.picocontainer.Parameter;
import org.picocontainer.PicoCompositionException;
import org.picocontainer.PicoContainer;
import org.picocontainer.PicoVisitor;
/**
* A CollectionComponentParameter should be used to support inject an {@link Array}, a
* {@link Collection}or {@link Map}of components automatically. The collection will contain
* all components of a special type and additionally the type of the key may be specified. In
* case of a map, the map's keys are the one of the component adapter.
*
* @author Aslak Hellesøy
* @author Jörg Schaible
*/
@SuppressWarnings("serial")
public class CollectionComponentParameter extends AbstractParameter implements Parameter, Serializable {
/**
* Use ARRAY as {@link Parameter}for an Array that must have elements.
*/
public static final CollectionComponentParameter ARRAY = new CollectionComponentParameter();
/**
* Use ARRAY_ALLOW_EMPTY as {@link Parameter}for an Array that may have no
* elements.
*/
public static final CollectionComponentParameter ARRAY_ALLOW_EMPTY = new CollectionComponentParameter(true);
private final boolean emptyCollection;
private final Class componentKeyType;
private final Class componentValueType;
/**
* Expect an {@link Array}of an appropriate type as parameter. At least one component of
* the array's component type must exist.
*/
public CollectionComponentParameter() {
this(false);
}
/**
* Expect an {@link Array}of an appropriate type as parameter.
*
* @param emptyCollection true if an empty array also is a valid dependency
* resolution.
*/
public CollectionComponentParameter(final boolean emptyCollection) {
this(Void.TYPE, emptyCollection);
}
/**
* Expect any of the collection types {@link Array},{@link Collection}or {@link Map}as
* parameter.
*
* @param componentValueType the type of the components (ignored in case of an Array)
* @param emptyCollection true if an empty collection resolves the
* dependency.
*/
public CollectionComponentParameter(final Class componentValueType, final boolean emptyCollection) {
this(Object.class, componentValueType, emptyCollection);
}
/**
* Expect any of the collection types {@link Array},{@link Collection}or {@link Map}as
* parameter.
*
* @param componentKeyType the type of the component's key
* @param componentValueType the type of the components (ignored in case of an Array)
* @param emptyCollection true if an empty collection resolves the
* dependency.
*/
public CollectionComponentParameter(final Class componentKeyType, final Class componentValueType, final boolean emptyCollection) {
this.emptyCollection = emptyCollection;
this.componentKeyType = componentKeyType;
this.componentValueType = componentValueType;
}
/**
* Check for a successful dependency resolution of the parameter for the expected type. The
* dependency can only be satisfied if the expected type is one of the collection types
* {@link Array},{@link Collection}or {@link Map}. An empty collection is only a valid
* resolution, if the emptyCollection flag was set.
*
* @param container {@inheritDoc}
* @param injecteeAdapter
*@param expectedType {@inheritDoc}
* @param expectedNameBinding {@inheritDoc}
* @param useNames
* @param binding @return true if matching components were found or an empty collective type
* is allowed
*/
public Resolver resolve(final PicoContainer container, final ComponentAdapter forAdapter,
final ComponentAdapter injecteeAdapter, final Type expectedType, final NameBinding expectedNameBinding,
final boolean useNames, final Annotation binding) {
final Class collectionType = getCollectionType(expectedType);
if (collectionType != null) {
final Map> componentAdapters = getMatchingComponentAdapters(container, forAdapter,
componentKeyType, getValueType(expectedType));
return new Resolver() {
public boolean isResolved() {
return emptyCollection || componentAdapters.size() > 0;
}
public Object resolveInstance() {
Object result = null;
if (collectionType.isArray()) {
result = getArrayInstance(container, collectionType, componentAdapters);
} else if (Map.class.isAssignableFrom(collectionType)) {
result = getMapInstance(container, collectionType, componentAdapters);
} else if (Collection.class.isAssignableFrom(collectionType)) {
result = getCollectionInstance(container, collectionType,
componentAdapters, expectedNameBinding, useNames);
} else {
throw new PicoCompositionException(expectedType + " is not a collective type");
}
return result;
}
public ComponentAdapter getComponentAdapter() {
return null;
}
};
}
return new Parameter.NotResolved();
}
private Class getCollectionType(final Type expectedType) {
if (expectedType instanceof Class) {
return getCollectionType((Class) expectedType);
} else if (expectedType instanceof ParameterizedType) {
ParameterizedType type = (ParameterizedType) expectedType;
return getCollectionType(type.getRawType());
}
else if (expectedType instanceof GenericArrayType) {
GenericArrayType type = (GenericArrayType) expectedType;
Class baseType = getGenericArrayBaseType(type.getGenericComponentType());
return Array.newInstance(baseType, 0).getClass();
}
throw new IllegalArgumentException("Unable to get collection type from " + expectedType);
}
private Class getGenericArrayBaseType(final Type expectedType) {
if (expectedType instanceof Class) {
Class type = (Class) expectedType;
return type;
}
else if (expectedType instanceof ParameterizedType) {
ParameterizedType type = (ParameterizedType) expectedType;
return getGenericArrayBaseType(type.getRawType());
}
throw new IllegalArgumentException("Unable to get collection type from " + expectedType);
}
/**
* Verify a successful dependency resolution of the parameter for the expected type. The
* method will only return if the expected type is one of the collection types {@link Array},
* {@link Collection}or {@link Map}. An empty collection is only a valid resolution, if
* the emptyCollection flag was set.
*
* @param container {@inheritDoc}
* @param adapter {@inheritDoc}
* @param expectedType {@inheritDoc}
* @param expectedNameBinding {@inheritDoc}
* @param useNames
* @param binding
* @throws PicoCompositionException {@inheritDoc}
*/
public void verify(final PicoContainer container,
final ComponentAdapter adapter,
final Type expectedType,
final NameBinding expectedNameBinding, final boolean useNames, final Annotation binding) {
final Class collectionType = getCollectionType(expectedType);
if (collectionType != null) {
final Class valueType = getValueType(expectedType);
final Collection componentAdapters =
getMatchingComponentAdapters(container, adapter, componentKeyType, valueType).values();
if (componentAdapters.isEmpty()) {
if (!emptyCollection) {
throw new PicoCompositionException(expectedType
+ " not resolvable, no components of type "
+ valueType.getName()
+ " available");
}
} else {
for (Object componentAdapter1 : componentAdapters) {
final ComponentAdapter componentAdapter = (ComponentAdapter) componentAdapter1;
componentAdapter.verify(container);
}
}
} else {
throw new PicoCompositionException(expectedType + " is not a collective type");
}
}
/**
* Visit the current {@link Parameter}.
*
* @see org.picocontainer.Parameter#accept(org.picocontainer.PicoVisitor)
*/
public void accept(final PicoVisitor visitor) {
visitor.visitParameter(this);
}
/**
* Evaluate whether the given component adapter will be part of the collective type.
*
* @param adapter a ComponentAdapter value
* @return true if the adapter takes part
*/
protected boolean evaluate(final ComponentAdapter adapter) {
return adapter != null; // use parameter, prevent compiler warning
}
/**
* Collect the matching ComponentAdapter instances.
*
* @param container container to use for dependency resolution
* @param adapter {@link ComponentAdapter} to exclude
* @param keyType the compatible type of the key
* @param valueType the compatible type of the addComponent
* @return a {@link Map} with the ComponentAdapter instances and their component keys as map key.
*/
@SuppressWarnings({"unchecked"})
protected Map>
getMatchingComponentAdapters(final PicoContainer container, final ComponentAdapter adapter,
final Class keyType, final Class valueType) {
final Map> adapterMap = new LinkedHashMap>();
final PicoContainer parent = container.getParent();
if (parent != null) {
adapterMap.putAll(getMatchingComponentAdapters(parent, adapter, keyType, valueType));
}
final Collection> allAdapters = container.getComponentAdapters();
for (ComponentAdapter componentAdapter : allAdapters) {
adapterMap.remove(componentAdapter.getComponentKey());
}
final List adapterList = List.class.cast(container.getComponentAdapters(valueType));
for (ComponentAdapter componentAdapter : adapterList) {
final Object key = componentAdapter.getComponentKey();
if (adapter != null && key.equals(adapter.getComponentKey())) {
continue;
}
if (keyType.isAssignableFrom(key.getClass()) && evaluate(componentAdapter)) {
adapterMap.put(key, componentAdapter);
}
}
return adapterMap;
}
private Class getCollectionType(final Class collectionType) {
if (collectionType.isArray() ||
Map.class.isAssignableFrom(collectionType) ||
Collection.class.isAssignableFrom(collectionType)) {
return collectionType;
}
return null;
}
private Class getValueType(final Type collectionType) {
if (collectionType instanceof Class) {
return getValueType((Class) collectionType);
} else if (collectionType instanceof ParameterizedType) {
return getValueType((ParameterizedType) collectionType); }
else if (collectionType instanceof GenericArrayType) {
GenericArrayType genericArrayType = (GenericArrayType) collectionType;
return getGenericArrayBaseType(genericArrayType.getGenericComponentType());
}
throw new IllegalArgumentException("Unable to determine collection type from " + collectionType);
}
private Class getValueType(final Class collectionType) {
Class valueType = componentValueType;
if (collectionType.isArray()) {
valueType = collectionType.getComponentType();
}
return valueType;
}
private Class getValueType(final ParameterizedType collectionType) {
Class valueType = componentValueType;
if (Collection.class.isAssignableFrom((Class) collectionType.getRawType())) {
Type type = collectionType.getActualTypeArguments()[0];
if (type instanceof Class) {
if (((Class)type).isAssignableFrom(valueType)) {
return valueType;
}
valueType = (Class) type;
}
}
return valueType;
}
private Object[] getArrayInstance(final PicoContainer container,
final Class expectedType,
final Map> adapterList) {
final Object[] result = (Object[]) Array.newInstance(expectedType.getComponentType(), adapterList.size());
int i = 0;
for (ComponentAdapter componentAdapter : adapterList.values()) {
result[i] = container.getComponent(componentAdapter.getComponentKey());
i++;
}
return result;
}
@SuppressWarnings({"unchecked"})
private Collection getCollectionInstance(final PicoContainer container,
final Class expectedType,
final Map> adapterList, final NameBinding expectedNameBinding, final boolean useNames) {
Class collectionType = expectedType;
if (collectionType.isInterface()) {
// The order of tests are significant. The least generic types last.
if (List.class.isAssignableFrom(collectionType)) {
collectionType = ArrayList.class;
// } else if (BlockingQueue.class.isAssignableFrom(collectionType)) {
// collectionType = ArrayBlockingQueue.class;
// } else if (Queue.class.isAssignableFrom(collectionType)) {
// collectionType = LinkedList.class;
} else if (SortedSet.class.isAssignableFrom(collectionType)) {
collectionType = TreeSet.class;
} else if (Set.class.isAssignableFrom(collectionType)) {
collectionType = HashSet.class;
} else if (Collection.class.isAssignableFrom(collectionType)) {
collectionType = ArrayList.class;
}
}
try {
Collection result = collectionType.newInstance();
for (ComponentAdapter componentAdapter : adapterList.values()) {
if (!useNames || componentAdapter.getComponentKey() == expectedNameBinding) {
result.add(container.getComponent(componentAdapter.getComponentKey()));
}
}
return result;
} catch (InstantiationException e) {
///CLOVER:OFF
throw new PicoCompositionException(e);
///CLOVER:ON
} catch (IllegalAccessException e) {
///CLOVER:OFF
throw new PicoCompositionException(e);
///CLOVER:ON
}
}
@SuppressWarnings({"unchecked"})
private Map getMapInstance(final PicoContainer container,
final Class expectedType,
final Map> adapterList) {
Class collectionType = expectedType;
if (collectionType.isInterface()) {
// The order of tests are significant. The least generic types last.
if (SortedMap.class.isAssignableFrom(collectionType)) {
collectionType = TreeMap.class;
// } else if (ConcurrentMap.class.isAssignableFrom(collectionType)) {
// collectionType = ConcurrentHashMap.class;
} else if (Map.class.isAssignableFrom(collectionType)) {
collectionType = HashMap.class;
}
}
try {
Map result = collectionType.newInstance();
for (Map.Entry> entry : adapterList.entrySet()) {
final Object key = entry.getKey();
result.put(key, container.getComponent(key));
}
return result;
} catch (InstantiationException e) {
///CLOVER:OFF
throw new PicoCompositionException(e);
///CLOVER:ON
} catch (IllegalAccessException e) {
///CLOVER:OFF
throw new PicoCompositionException(e);
///CLOVER:ON
}
}
}