| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.commons.configuration2; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.stream.Collectors; |
| |
| import org.apache.commons.configuration2.event.ConfigurationEvent; |
| import org.apache.commons.configuration2.event.EventListener; |
| import org.apache.commons.configuration2.ex.ConfigurationRuntimeException; |
| import org.apache.commons.configuration2.interpol.ConfigurationInterpolator; |
| import org.apache.commons.configuration2.tree.ConfigurationNodeVisitorAdapter; |
| import org.apache.commons.configuration2.tree.ImmutableNode; |
| import org.apache.commons.configuration2.tree.InMemoryNodeModel; |
| import org.apache.commons.configuration2.tree.InMemoryNodeModelSupport; |
| import org.apache.commons.configuration2.tree.NodeHandler; |
| import org.apache.commons.configuration2.tree.NodeModel; |
| import org.apache.commons.configuration2.tree.NodeSelector; |
| import org.apache.commons.configuration2.tree.NodeTreeWalker; |
| import org.apache.commons.configuration2.tree.QueryResult; |
| import org.apache.commons.configuration2.tree.ReferenceNodeHandler; |
| import org.apache.commons.configuration2.tree.TrackedNodeModel; |
| import org.apache.commons.lang3.ObjectUtils; |
| |
| /** |
| * <p> |
| * A specialized hierarchical configuration implementation that is based on a structure of {@link ImmutableNode} |
| * objects. |
| * </p> |
| */ |
| public class BaseHierarchicalConfiguration extends AbstractHierarchicalConfiguration<ImmutableNode> implements InMemoryNodeModelSupport { |
| |
| /** |
| * A specialized visitor base class that can be used for storing the tree of configuration nodes. The basic idea is that |
| * each node can be associated with a reference object. This reference object has a concrete meaning in a derived class, |
| * e.g. an entry in a JNDI context or an XML element. When the configuration tree is set up, the {@code load()} method |
| * is responsible for setting the reference objects. When the configuration tree is later modified, new nodes do not |
| * have a defined reference object. This visitor class processes all nodes and finds the ones without a defined |
| * reference object. For those nodes the {@code insert()} method is called, which must be defined in concrete sub |
| * classes. This method can perform all steps to integrate the new node into the original structure. |
| */ |
| protected abstract static class BuilderVisitor extends ConfigurationNodeVisitorAdapter<ImmutableNode> { |
| /** |
| * Inserts a new node into the structure constructed by this builder. This method is called for each node that has been |
| * added to the configuration tree after the configuration has been loaded from its source. These new nodes have to be |
| * inserted into the original structure. The passed in nodes define the position of the node to be inserted: its parent |
| * and the siblings between to insert. |
| * |
| * @param newNode the node to be inserted |
| * @param parent the parent node |
| * @param sibling1 the sibling after which the node is to be inserted; can be <b>null</b> if the new node is going to be |
| * the first child node |
| * @param sibling2 the sibling before which the node is to be inserted; can be <b>null</b> if the new node is going to |
| * be the last child node |
| * @param refHandler the {@code ReferenceNodeHandler} |
| */ |
| protected abstract void insert(ImmutableNode newNode, ImmutableNode parent, ImmutableNode sibling1, ImmutableNode sibling2, |
| ReferenceNodeHandler refHandler); |
| |
| /** |
| * Inserts new children that have been added to the specified node. |
| * |
| * @param node the current node to be processed |
| * @param refHandler the {@code ReferenceNodeHandler} |
| */ |
| private void insertNewChildNodes(final ImmutableNode node, final ReferenceNodeHandler refHandler) { |
| final Collection<ImmutableNode> subNodes = new LinkedList<>(refHandler.getChildren(node)); |
| final Iterator<ImmutableNode> children = subNodes.iterator(); |
| ImmutableNode sibling1; |
| ImmutableNode nd = null; |
| |
| while (children.hasNext()) { |
| // find the next new node |
| do { |
| sibling1 = nd; |
| nd = children.next(); |
| } while (refHandler.getReference(nd) != null && children.hasNext()); |
| |
| if (refHandler.getReference(nd) == null) { |
| // find all following new nodes |
| final List<ImmutableNode> newNodes = new LinkedList<>(); |
| newNodes.add(nd); |
| while (children.hasNext()) { |
| nd = children.next(); |
| if (refHandler.getReference(nd) != null) { |
| break; |
| } |
| newNodes.add(nd); |
| } |
| |
| // Insert all new nodes |
| final ImmutableNode sibling2 = refHandler.getReference(nd) == null ? null : nd; |
| for (final ImmutableNode insertNode : newNodes) { |
| if (refHandler.getReference(insertNode) == null) { |
| insert(insertNode, node, sibling1, sibling2, refHandler); |
| sibling1 = insertNode; |
| } |
| } |
| } |
| } |
| } |
| |
| /** |
| * Updates a node that already existed in the original hierarchy. This method is called for each node that has an |
| * assigned reference object. A concrete implementation should update the reference according to the node's current |
| * value. |
| * |
| * @param node the current node to be processed |
| * @param reference the reference object for this node |
| * @param refHandler the {@code ReferenceNodeHandler} |
| */ |
| protected abstract void update(ImmutableNode node, Object reference, ReferenceNodeHandler refHandler); |
| |
| /** |
| * Updates the value of a node. If this node is associated with a reference object, the {@code update()} method is |
| * called. |
| * |
| * @param node the current node to be processed |
| * @param refHandler the {@code ReferenceNodeHandler} |
| */ |
| private void updateNode(final ImmutableNode node, final ReferenceNodeHandler refHandler) { |
| final Object reference = refHandler.getReference(node); |
| if (reference != null) { |
| update(node, reference, refHandler); |
| } |
| } |
| |
| @Override |
| public void visitBeforeChildren(final ImmutableNode node, final NodeHandler<ImmutableNode> handler) { |
| final ReferenceNodeHandler refHandler = (ReferenceNodeHandler) handler; |
| updateNode(node, refHandler); |
| insertNewChildNodes(node, refHandler); |
| } |
| } |
| |
| /** |
| * A specialized visitor implementation which constructs the root node of a configuration with all variables replaced by |
| * their interpolated values. |
| */ |
| private final class InterpolatedVisitor extends ConfigurationNodeVisitorAdapter<ImmutableNode> { |
| /** A stack for managing node builder instances. */ |
| private final List<ImmutableNode.Builder> builderStack; |
| |
| /** The resulting root node. */ |
| private ImmutableNode interpolatedRoot; |
| |
| /** |
| * Creates a new instance of {@code InterpolatedVisitor}. |
| */ |
| public InterpolatedVisitor() { |
| builderStack = new LinkedList<>(); |
| } |
| |
| /** |
| * Gets the result of this builder: the root node of the interpolated nodes hierarchy. |
| * |
| * @return the resulting root node |
| */ |
| public ImmutableNode getInterpolatedRoot() { |
| return interpolatedRoot; |
| } |
| |
| /** |
| * Handles interpolation for a node with no children. If interpolation does not change this node, it is copied as is to |
| * the resulting structure. Otherwise, a new node is created with the interpolated values. |
| * |
| * @param node the current node to be processed |
| * @param handler the {@code NodeHandler} |
| */ |
| private void handleLeafNode(final ImmutableNode node, final NodeHandler<ImmutableNode> handler) { |
| final Object value = interpolate(node.getValue()); |
| final Map<String, Object> interpolatedAttributes = new HashMap<>(); |
| final boolean attributeChanged = interpolateAttributes(node, handler, interpolatedAttributes); |
| final ImmutableNode newNode = valueChanged(value, handler.getValue(node)) || attributeChanged |
| ? new ImmutableNode.Builder().name(handler.nodeName(node)).value(value).addAttributes(interpolatedAttributes).create() |
| : node; |
| storeInterpolatedNode(newNode); |
| } |
| |
| /** |
| * Returns a map with interpolated attributes of the passed in node. |
| * |
| * @param node the current node to be processed |
| * @param handler the {@code NodeHandler} |
| * @return the map with interpolated attributes |
| */ |
| private Map<String, Object> interpolateAttributes(final ImmutableNode node, final NodeHandler<ImmutableNode> handler) { |
| final Map<String, Object> attributes = new HashMap<>(); |
| interpolateAttributes(node, handler, attributes); |
| return attributes; |
| } |
| |
| /** |
| * Populates a map with interpolated attributes of the passed in node. |
| * |
| * @param node the current node to be processed |
| * @param handler the {@code NodeHandler} |
| * @param interpolatedAttributes a map for storing the results |
| * @return a flag whether an attribute value was changed by interpolation |
| */ |
| private boolean interpolateAttributes(final ImmutableNode node, final NodeHandler<ImmutableNode> handler, |
| final Map<String, Object> interpolatedAttributes) { |
| boolean attributeChanged = false; |
| for (final String attr : handler.getAttributes(node)) { |
| final Object attrValue = interpolate(handler.getAttributeValue(node, attr)); |
| if (valueChanged(attrValue, handler.getAttributeValue(node, attr))) { |
| attributeChanged = true; |
| } |
| interpolatedAttributes.put(attr, attrValue); |
| } |
| return attributeChanged; |
| } |
| |
| /** |
| * Returns a flag whether the given node is a leaf. This is the case if it does not have children. |
| * |
| * @param node the node in question |
| * @param handler the {@code NodeHandler} |
| * @return a flag whether this is a leaf node |
| */ |
| private boolean isLeafNode(final ImmutableNode node, final NodeHandler<ImmutableNode> handler) { |
| return handler.getChildren(node).isEmpty(); |
| } |
| |
| /** |
| * Returns the top-level element from the stack without removing it. |
| * |
| * @return the top-level element from the stack |
| */ |
| private ImmutableNode.Builder peek() { |
| return builderStack.get(0); |
| } |
| |
| /** |
| * Pops the top-level element from the stack. |
| * |
| * @return the element popped from the stack |
| */ |
| private ImmutableNode.Builder pop() { |
| return builderStack.remove(0); |
| } |
| |
| /** |
| * Pushes a new builder on the stack. |
| * |
| * @param builder the builder |
| */ |
| private void push(final ImmutableNode.Builder builder) { |
| builderStack.add(0, builder); |
| } |
| |
| /** |
| * Stores a processed node. Per default, the node is added to the current builder on the stack. If no such builder |
| * exists, this is the result node. |
| * |
| * @param node the node to be stored |
| */ |
| private void storeInterpolatedNode(final ImmutableNode node) { |
| if (builderStack.isEmpty()) { |
| interpolatedRoot = node; |
| } else { |
| peek().addChild(node); |
| } |
| } |
| |
| /** |
| * Tests whether a value is changed because of interpolation. |
| * |
| * @param interpolatedValue the interpolated value |
| * @param value the original value |
| * @return a flag whether the value was changed |
| */ |
| private boolean valueChanged(final Object interpolatedValue, final Object value) { |
| return ObjectUtils.notEqual(interpolatedValue, value); |
| } |
| |
| @Override |
| public void visitAfterChildren(final ImmutableNode node, final NodeHandler<ImmutableNode> handler) { |
| if (!isLeafNode(node, handler)) { |
| final ImmutableNode newNode = pop().create(); |
| storeInterpolatedNode(newNode); |
| } |
| } |
| |
| @Override |
| public void visitBeforeChildren(final ImmutableNode node, final NodeHandler<ImmutableNode> handler) { |
| if (isLeafNode(node, handler)) { |
| handleLeafNode(node, handler); |
| } else { |
| final ImmutableNode.Builder builder = new ImmutableNode.Builder(handler.getChildrenCount(node, null)).name(handler.nodeName(node)) |
| .value(interpolate(handler.getValue(node))).addAttributes(interpolateAttributes(node, handler)); |
| push(builder); |
| } |
| } |
| } |
| |
| /** |
| * Creates the {@code NodeModel} for this configuration based on a passed in source configuration. This implementation |
| * creates an {@link InMemoryNodeModel}. If the passed in source configuration is defined, its root node also becomes |
| * the root node of this configuration. Otherwise, a new, empty root node is used. |
| * |
| * @param c the configuration that is to be copied |
| * @return the {@code NodeModel} for the new configuration |
| */ |
| private static NodeModel<ImmutableNode> createNodeModel(final HierarchicalConfiguration<ImmutableNode> c) { |
| return new InMemoryNodeModel(obtainRootNode(c)); |
| } |
| |
| /** |
| * Obtains the root node from a configuration whose data is to be copied. It has to be ensured that the synchronizer is |
| * called correctly. |
| * |
| * @param c the configuration that is to be copied |
| * @return the root node of this configuration |
| */ |
| private static ImmutableNode obtainRootNode(final HierarchicalConfiguration<ImmutableNode> c) { |
| return c != null ? c.getNodeModel().getNodeHandler().getRootNode() : null; |
| } |
| |
| /** |
| * Creates a list with immutable configurations from the given input list. |
| * |
| * @param subs a list with mutable configurations |
| * @return a list with corresponding immutable configurations |
| */ |
| private static List<ImmutableHierarchicalConfiguration> toImmutable(final List<? extends HierarchicalConfiguration<?>> subs) { |
| return subs.stream().map(ConfigurationUtils::unmodifiableConfiguration).collect(Collectors.toList()); |
| } |
| |
| /** A listener for reacting on changes caused by sub configurations. */ |
| private final EventListener<ConfigurationEvent> changeListener; |
| |
| /** |
| * Creates a new instance of {@code BaseHierarchicalConfiguration}. |
| */ |
| public BaseHierarchicalConfiguration() { |
| this((HierarchicalConfiguration<ImmutableNode>) null); |
| } |
| |
| /** |
| * Creates a new instance of {@code BaseHierarchicalConfiguration} and copies all data contained in the specified |
| * configuration into the new one. |
| * |
| * @param c the configuration that is to be copied (if <b>null</b>, this constructor will behave like the standard |
| * constructor) |
| * @since 1.4 |
| */ |
| public BaseHierarchicalConfiguration(final HierarchicalConfiguration<ImmutableNode> c) { |
| this(createNodeModel(c)); |
| } |
| |
| /** |
| * Creates a new instance of {@code BaseHierarchicalConfiguration} and initializes it with the given {@code NodeModel}. |
| * |
| * @param model the {@code NodeModel} |
| */ |
| protected BaseHierarchicalConfiguration(final NodeModel<ImmutableNode> model) { |
| super(model); |
| changeListener = createChangeListener(); |
| } |
| |
| /** |
| * {@inheritDoc} This implementation resolves the node(s) selected by the given key. If not a single node is selected, |
| * an empty list is returned. Otherwise, sub configurations for each child of the node are created. |
| */ |
| @Override |
| public List<HierarchicalConfiguration<ImmutableNode>> childConfigurationsAt(final String key) { |
| List<ImmutableNode> nodes; |
| beginRead(false); |
| try { |
| nodes = fetchFilteredNodeResults(key); |
| } finally { |
| endRead(); |
| } |
| |
| if (nodes.size() != 1) { |
| return Collections.emptyList(); |
| } |
| |
| return nodes.get(0).stream().map(this::createIndependentSubConfigurationForNode).collect(Collectors.toList()); |
| } |
| |
| /** |
| * {@inheritDoc} This method works like {@link #childConfigurationsAt(String)}; however, depending on the value of the |
| * {@code supportUpdates} flag, connected sub configurations may be created. |
| */ |
| @Override |
| public List<HierarchicalConfiguration<ImmutableNode>> childConfigurationsAt(final String key, final boolean supportUpdates) { |
| if (!supportUpdates) { |
| return childConfigurationsAt(key); |
| } |
| |
| final InMemoryNodeModel parentModel = getSubConfigurationParentModel(); |
| return createConnectedSubConfigurations(this, parentModel.trackChildNodes(key, this)); |
| } |
| |
| /** |
| * {@inheritDoc} This implementation creates a new instance of {@link InMemoryNodeModel}, initialized with this |
| * configuration's root node. This has the effect that although the same nodes are used, the original and copied |
| * configurations are independent on each other. |
| */ |
| @Override |
| protected NodeModel<ImmutableNode> cloneNodeModel() { |
| return new InMemoryNodeModel(getModel().getNodeHandler().getRootNode()); |
| } |
| |
| /** |
| * {@inheritDoc} This is a short form for {@code configurationAt(key, |
| * <b>false</b>)}. |
| * |
| * @throws ConfigurationRuntimeException if the key does not select a single node |
| */ |
| @Override |
| public HierarchicalConfiguration<ImmutableNode> configurationAt(final String key) { |
| return configurationAt(key, false); |
| } |
| |
| /** |
| * {@inheritDoc} The result of this implementation depends on the {@code supportUpdates} flag: If it is <b>false</b>, a |
| * plain {@code BaseHierarchicalConfiguration} is returned using the selected node as root node. This is suitable for |
| * read-only access to properties. Because the configuration returned in this case is not connected to the parent |
| * configuration, updates on properties made by one configuration are not reflected by the other one. A value of |
| * <b>true</b> for this parameter causes a tracked node to be created, and result is a {@link SubnodeConfiguration} |
| * based on this tracked node. This configuration is really connected to its parent, so that updated properties are |
| * visible on both. |
| * |
| * @see SubnodeConfiguration |
| * @throws ConfigurationRuntimeException if the key does not select a single node |
| */ |
| @Override |
| public HierarchicalConfiguration<ImmutableNode> configurationAt(final String key, final boolean supportUpdates) { |
| beginRead(false); |
| try { |
| return supportUpdates ? createConnectedSubConfiguration(key) : createIndependentSubConfiguration(key); |
| } finally { |
| endRead(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} This implementation creates sub configurations in the same way as described for |
| * {@link #configurationAt(String)}. |
| */ |
| @Override |
| public List<HierarchicalConfiguration<ImmutableNode>> configurationsAt(final String key) { |
| List<ImmutableNode> nodes; |
| beginRead(false); |
| try { |
| nodes = fetchFilteredNodeResults(key); |
| } finally { |
| endRead(); |
| } |
| return nodes.stream().map(this::createIndependentSubConfigurationForNode).collect(Collectors.toList()); |
| } |
| |
| /** |
| * {@inheritDoc} This implementation creates tracked nodes for the specified key. Then sub configurations for these |
| * nodes are created and returned. |
| */ |
| @Override |
| public List<HierarchicalConfiguration<ImmutableNode>> configurationsAt(final String key, final boolean supportUpdates) { |
| if (!supportUpdates) { |
| return configurationsAt(key); |
| } |
| |
| InMemoryNodeModel parentModel; |
| beginRead(false); |
| try { |
| parentModel = getSubConfigurationParentModel(); |
| } finally { |
| endRead(); |
| } |
| |
| final Collection<NodeSelector> selectors = parentModel.selectAndTrackNodes(key, this); |
| return createConnectedSubConfigurations(this, selectors); |
| } |
| |
| /** |
| * Creates a listener which reacts on all changes on this configuration or one of its {@code SubnodeConfiguration} |
| * instances. If such a change is detected, some updates have to be performed. |
| * |
| * @return the newly created change listener |
| */ |
| private EventListener<ConfigurationEvent> createChangeListener() { |
| return this::subnodeConfigurationChanged; |
| } |
| |
| /** |
| * Creates a sub configuration from the specified key which is connected to this configuration. This implementation |
| * creates a {@link SubnodeConfiguration} with a tracked node identified by the passed in key. |
| * |
| * @param key the key of the sub configuration |
| * @return the new sub configuration |
| */ |
| private BaseHierarchicalConfiguration createConnectedSubConfiguration(final String key) { |
| final NodeSelector selector = getSubConfigurationNodeSelector(key); |
| getSubConfigurationParentModel().trackNode(selector, this); |
| return createSubConfigurationForTrackedNode(selector, this); |
| } |
| |
| /** |
| * Creates a list of connected sub configurations based on a passed in list of node selectors. |
| * |
| * @param parentModelSupport the parent node model support object |
| * @param selectors the list of {@code NodeSelector} objects |
| * @return the list with sub configurations |
| */ |
| private List<HierarchicalConfiguration<ImmutableNode>> createConnectedSubConfigurations(final InMemoryNodeModelSupport parentModelSupport, |
| final Collection<NodeSelector> selectors) { |
| return selectors.stream().map(sel -> createSubConfigurationForTrackedNode(sel, parentModelSupport)).collect(Collectors.toList()); |
| } |
| |
| /** |
| * Creates a sub configuration from the specified key which is independent on this configuration. This means that the |
| * sub configuration operates on a separate node model (although the nodes are initially shared). |
| * |
| * @param key the key of the sub configuration |
| * @return the new sub configuration |
| */ |
| private BaseHierarchicalConfiguration createIndependentSubConfiguration(final String key) { |
| final List<ImmutableNode> targetNodes = fetchFilteredNodeResults(key); |
| final int size = targetNodes.size(); |
| if (size != 1) { |
| throw new ConfigurationRuntimeException("Passed in key must select exactly one node (found %,d): %s", size, key); |
| } |
| final BaseHierarchicalConfiguration sub = new BaseHierarchicalConfiguration(new InMemoryNodeModel(targetNodes.get(0))); |
| initSubConfiguration(sub); |
| return sub; |
| } |
| |
| /** |
| * Returns an initialized sub configuration for this configuration that is based on another |
| * {@code BaseHierarchicalConfiguration}. Thus, it is independent from this configuration. |
| * |
| * @param node the root node for the sub configuration |
| * @return the initialized sub configuration |
| */ |
| private BaseHierarchicalConfiguration createIndependentSubConfigurationForNode(final ImmutableNode node) { |
| final BaseHierarchicalConfiguration sub = new BaseHierarchicalConfiguration(new InMemoryNodeModel(node)); |
| initSubConfiguration(sub); |
| return sub; |
| } |
| |
| /** |
| * Creates a connected sub configuration based on a selector for a tracked node. |
| * |
| * @param selector the {@code NodeSelector} |
| * @param parentModelSupport the {@code InMemoryNodeModelSupport} object for the parent node model |
| * @return the newly created sub configuration |
| * @since 2.0 |
| */ |
| protected SubnodeConfiguration createSubConfigurationForTrackedNode(final NodeSelector selector, final InMemoryNodeModelSupport parentModelSupport) { |
| final SubnodeConfiguration subConfig = new SubnodeConfiguration(this, new TrackedNodeModel(parentModelSupport, selector, true)); |
| initSubConfigurationForThisParent(subConfig); |
| return subConfig; |
| } |
| |
| /** |
| * Creates a root node for a subset configuration based on the passed in query results. This method creates a new root |
| * node and adds the children and attributes of all result nodes to it. If only a single node value is defined, it is |
| * assigned as value of the new root node. |
| * |
| * @param results the collection of query results |
| * @return the root node for the subset configuration |
| */ |
| private ImmutableNode createSubsetRootNode(final Collection<QueryResult<ImmutableNode>> results) { |
| final ImmutableNode.Builder builder = new ImmutableNode.Builder(); |
| Object value = null; |
| int valueCount = 0; |
| |
| for (final QueryResult<ImmutableNode> result : results) { |
| if (result.isAttributeResult()) { |
| builder.addAttribute(result.getAttributeName(), result.getAttributeValue(getModel().getNodeHandler())); |
| } else { |
| if (result.getNode().getValue() != null) { |
| value = result.getNode().getValue(); |
| valueCount++; |
| } |
| builder.addChildren(result.getNode().getChildren()); |
| builder.addAttributes(result.getNode().getAttributes()); |
| } |
| } |
| |
| if (valueCount == 1) { |
| builder.value(value); |
| } |
| return builder.create(); |
| } |
| |
| /** |
| * Executes a query on the specified key and filters it for node results. |
| * |
| * @param key the key |
| * @return the filtered list with result nodes |
| */ |
| private List<ImmutableNode> fetchFilteredNodeResults(final String key) { |
| final NodeHandler<ImmutableNode> handler = getModel().getNodeHandler(); |
| return resolveNodeKey(handler.getRootNode(), key, handler); |
| } |
| |
| /** |
| * {@inheritDoc} This implementation returns the {@code InMemoryNodeModel} used by this configuration. |
| */ |
| @Override |
| public InMemoryNodeModel getNodeModel() { |
| return (InMemoryNodeModel) super.getNodeModel(); |
| } |
| |
| /** |
| * Gets the {@code NodeSelector} to be used for a sub configuration based on the passed in key. This method is called |
| * whenever a sub configuration is to be created. This base implementation returns a new {@code NodeSelector} |
| * initialized with the passed in key. Sub classes may override this method if they have a different strategy for |
| * creating a selector. |
| * |
| * @param key the key of the sub configuration |
| * @return a {@code NodeSelector} for initializing a sub configuration |
| * @since 2.0 |
| */ |
| protected NodeSelector getSubConfigurationNodeSelector(final String key) { |
| return new NodeSelector(key); |
| } |
| |
| /** |
| * Gets the {@code InMemoryNodeModel} to be used as parent model for a new sub configuration. This method is called |
| * whenever a sub configuration is to be created. This base implementation returns the model of this configuration. Sub |
| * classes with different requirements for the parent models of sub configurations have to override it. |
| * |
| * @return the parent model for a new sub configuration |
| */ |
| protected InMemoryNodeModel getSubConfigurationParentModel() { |
| return (InMemoryNodeModel) getModel(); |
| } |
| |
| /** |
| * {@inheritDoc} This implementation first delegates to {@code childConfigurationsAt()} to create a list of mutable |
| * child configurations. Then a list with immutable wrapper configurations is created. |
| */ |
| @Override |
| public List<ImmutableHierarchicalConfiguration> immutableChildConfigurationsAt(final String key) { |
| return toImmutable(childConfigurationsAt(key)); |
| } |
| |
| /** |
| * {@inheritDoc} This implementation creates a {@code SubnodeConfiguration} by delegating to {@code configurationAt()}. |
| * Then an immutable wrapper is created and returned. |
| * |
| * @throws ConfigurationRuntimeException if the key does not select a single node |
| */ |
| @Override |
| public ImmutableHierarchicalConfiguration immutableConfigurationAt(final String key) { |
| return ConfigurationUtils.unmodifiableConfiguration(configurationAt(key)); |
| } |
| |
| /** |
| * {@inheritDoc} This implementation creates a {@code SubnodeConfiguration} by delegating to {@code configurationAt()}. |
| * Then an immutable wrapper is created and returned. |
| */ |
| @Override |
| public ImmutableHierarchicalConfiguration immutableConfigurationAt(final String key, final boolean supportUpdates) { |
| return ConfigurationUtils.unmodifiableConfiguration(configurationAt(key, supportUpdates)); |
| } |
| |
| /** |
| * {@inheritDoc} This implementation first delegates to {@code configurationsAt()} to create a list of |
| * {@code SubnodeConfiguration} objects. Then for each element of this list an unmodifiable wrapper is created. |
| */ |
| @Override |
| public List<ImmutableHierarchicalConfiguration> immutableConfigurationsAt(final String key) { |
| return toImmutable(configurationsAt(key)); |
| } |
| |
| /** |
| * Initializes properties of a sub configuration. A sub configuration inherits some settings from its parent, e.g. the |
| * expression engine or the synchronizer. The corresponding values are copied by this method. |
| * |
| * @param sub the sub configuration to be initialized |
| */ |
| private void initSubConfiguration(final BaseHierarchicalConfiguration sub) { |
| sub.setSynchronizer(getSynchronizer()); |
| sub.setExpressionEngine(getExpressionEngine()); |
| sub.setListDelimiterHandler(getListDelimiterHandler()); |
| sub.setThrowExceptionOnMissing(isThrowExceptionOnMissing()); |
| sub.getInterpolator().setParentInterpolator(getInterpolator()); |
| } |
| |
| /** |
| * Initializes a {@code SubnodeConfiguration} object. This method should be called for each sub configuration created |
| * for this configuration. It ensures that the sub configuration is correctly connected to its parent instance and that |
| * update events are correctly propagated. |
| * |
| * @param subConfig the sub configuration to be initialized |
| * @since 2.0 |
| */ |
| protected void initSubConfigurationForThisParent(final SubnodeConfiguration subConfig) { |
| initSubConfiguration(subConfig); |
| subConfig.addEventListener(ConfigurationEvent.ANY, changeListener); |
| } |
| |
| /** |
| * Returns a configuration with the same content as this configuration, but with all variables replaced by their actual |
| * values. This implementation is specific for hierarchical configurations. It clones the current configuration and runs |
| * a specialized visitor on the clone, which performs interpolation on the single configuration nodes. |
| * |
| * @return a configuration with all variables interpolated |
| * @since 1.5 |
| */ |
| @Override |
| public Configuration interpolatedConfiguration() { |
| final InterpolatedVisitor visitor = new InterpolatedVisitor(); |
| final NodeHandler<ImmutableNode> handler = getModel().getNodeHandler(); |
| NodeTreeWalker.INSTANCE.walkDFS(handler.getRootNode(), visitor, handler); |
| |
| final BaseHierarchicalConfiguration c = (BaseHierarchicalConfiguration) clone(); |
| c.getNodeModel().setRootNode(visitor.getInterpolatedRoot()); |
| return c; |
| } |
| |
| /** |
| * This method is always called when a subnode configuration created from this configuration has been modified. This |
| * implementation transforms the received event into an event of type {@code SUBNODE_CHANGED} and notifies the |
| * registered listeners. |
| * |
| * @param event the event describing the change |
| * @since 1.5 |
| */ |
| protected void subnodeConfigurationChanged(final ConfigurationEvent event) { |
| fireEvent(ConfigurationEvent.SUBNODE_CHANGED, null, event, event.isBeforeUpdate()); |
| } |
| |
| /** |
| * Creates a new {@code Configuration} object containing all keys that start with the specified prefix. This |
| * implementation will return a {@code BaseHierarchicalConfiguration} object so that the structure of the keys will be |
| * saved. The nodes selected by the prefix (it is possible that multiple nodes are selected) are mapped to the root node |
| * of the returned configuration, i.e. their children and attributes will become children and attributes of the new root |
| * node. However, a value of the root node is only set if exactly one of the selected nodes contain a value (if multiple |
| * nodes have a value, there is simply no way to decide how these values are merged together). Note that the returned |
| * {@code Configuration} object is not connected to its source configuration: updates on the source configuration are |
| * not reflected in the subset and vice versa. The returned configuration uses the same {@code Synchronizer} as this |
| * configuration. |
| * |
| * @param prefix the prefix of the keys for the subset |
| * @return a new configuration object representing the selected subset |
| */ |
| @Override |
| public Configuration subset(final String prefix) { |
| beginRead(false); |
| try { |
| final List<QueryResult<ImmutableNode>> results = fetchNodeList(prefix); |
| if (results.isEmpty()) { |
| return new BaseHierarchicalConfiguration(); |
| } |
| |
| final BaseHierarchicalConfiguration parent = this; |
| final BaseHierarchicalConfiguration result = new BaseHierarchicalConfiguration() { |
| @Override |
| public ConfigurationInterpolator getInterpolator() { |
| return parent.getInterpolator(); |
| } |
| |
| // Override interpolate to always interpolate on the parent |
| @Override |
| protected Object interpolate(final Object value) { |
| return parent.interpolate(value); |
| } |
| }; |
| result.getModel().setRootNode(createSubsetRootNode(results)); |
| |
| if (result.isEmpty()) { |
| return new BaseHierarchicalConfiguration(); |
| } |
| result.setSynchronizer(getSynchronizer()); |
| return result; |
| } finally { |
| endRead(); |
| } |
| } |
| } |
