| /* |
| * 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.jxpath; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * An object that aggregates {@link Functions} objects into a group Functions |
| * object. Since {@link JXPathContext} can only register a single Functions |
| * object, FunctionLibrary should always be used to group all Functions objects |
| * that need to be registered. |
| * |
| * @author Dmitri Plotnikov |
| * @version $Revision$ $Date$ |
| */ |
| public class FunctionLibrary implements Functions { |
| private List allFunctions = new ArrayList(); |
| private HashMap byNamespace = null; |
| |
| /** |
| * Add functions to the library |
| * @param functions to add |
| */ |
| public void addFunctions(Functions functions) { |
| allFunctions.add(functions); |
| byNamespace = null; |
| } |
| |
| /** |
| * Remove functions from the library. |
| * @param functions to remove |
| */ |
| public void removeFunctions(Functions functions) { |
| allFunctions.remove(functions); |
| byNamespace = null; |
| } |
| |
| /** |
| * Returns a set containing all namespaces used by the aggregated |
| * Functions. |
| * @return Set<String> |
| */ |
| public Set getUsedNamespaces() { |
| if (byNamespace == null) { |
| prepareCache(); |
| } |
| return byNamespace.keySet(); |
| } |
| |
| /** |
| * Returns a Function, if any, for the specified namespace, |
| * name and parameter types. |
| * @param namespace function namespace |
| * @param name function name |
| * @param parameters parameters |
| * @return Function found |
| */ |
| public Function getFunction(String namespace, String name, |
| Object[] parameters) { |
| if (byNamespace == null) { |
| prepareCache(); |
| } |
| Object candidates = byNamespace.get(namespace); |
| if (candidates instanceof Functions) { |
| return ((Functions) candidates).getFunction( |
| namespace, |
| name, |
| parameters); |
| } |
| if (candidates instanceof List) { |
| List list = (List) candidates; |
| int count = list.size(); |
| for (int i = 0; i < count; i++) { |
| Function function = |
| ((Functions) list.get(i)).getFunction( |
| namespace, |
| name, |
| parameters); |
| if (function != null) { |
| return function; |
| } |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * Prepare the cache. |
| */ |
| private void prepareCache() { |
| byNamespace = new HashMap(); |
| int count = allFunctions.size(); |
| for (int i = 0; i < count; i++) { |
| Functions funcs = (Functions) allFunctions.get(i); |
| Set namespaces = funcs.getUsedNamespaces(); |
| for (Iterator it = namespaces.iterator(); it.hasNext();) { |
| String ns = (String) it.next(); |
| Object candidates = byNamespace.get(ns); |
| if (candidates == null) { |
| byNamespace.put(ns, funcs); |
| } |
| else if (candidates instanceof Functions) { |
| List lst = new ArrayList(); |
| lst.add(candidates); |
| lst.add(funcs); |
| byNamespace.put(ns, lst); |
| } |
| else { |
| ((List) candidates).add(funcs); |
| } |
| } |
| } |
| } |
| } |