001 /**
002 * =========================================
003 * LibFormula : a free Java formula library
004 * =========================================
005 *
006 * Project Info: http://reporting.pentaho.org/libformula/
007 *
008 * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
009 *
010 * This library is free software; you can redistribute it and/or modify it under the terms
011 * of the GNU Lesser General Public License as published by the Free Software Foundation;
012 * either version 2.1 of the License, or (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016 * See the GNU Lesser General Public License for more details.
017 *
018 * You should have received a copy of the GNU Lesser General Public License along with this
019 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020 * Boston, MA 02111-1307, USA.
021 *
022 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023 * in the United States and other countries.]
024 *
025 *
026 * ------------
027 * $Id: DefaultFunctionRegistry.java 3325 2007-09-12 23:57:55Z tmorgner $
028 * ------------
029 * (C) Copyright 2006-2007, by Pentaho Corporation.
030 */
031 package org.jfree.formula.function;
032
033 import java.util.ArrayList;
034 import java.util.HashMap;
035 import java.util.HashSet;
036 import java.util.Iterator;
037
038 import org.jfree.util.Configuration;
039 import org.jfree.util.HashNMap;
040 import org.jfree.util.Log;
041 import org.jfree.util.ObjectUtilities;
042
043 /**
044 * Creation-Date: 02.11.2006, 12:48:32
045 *
046 * @author Thomas Morgner
047 */
048 public class DefaultFunctionRegistry implements FunctionRegistry
049 {
050 private static final String FUNCTIONS_PREFIX = "org.jfree.formula.functions.";
051 private static final String[] EMPTY_ARRAY = new String[0];
052 private static final FunctionCategory[] EMPTY_CATEGORIES = new FunctionCategory[0];
053
054 private FunctionCategory[] categories;
055 private HashNMap categoryFunctions;
056 private HashMap functions;
057 private HashMap functionMetaData;
058 private HashMap cachedFunctions;
059
060 public DefaultFunctionRegistry()
061 {
062 cachedFunctions = new HashMap();
063 categoryFunctions = new HashNMap();
064 functionMetaData = new HashMap();
065 functions = new HashMap();
066 categories = EMPTY_CATEGORIES;
067 }
068
069 public FunctionCategory[] getCategories()
070 {
071 return (FunctionCategory[]) categories.clone();
072 }
073
074 public Function[] getFunctions()
075 {
076 final String[] fnNames = getFunctionNames();
077 final ArrayList functions = new ArrayList(fnNames.length);
078 for (int i = 0; i < fnNames.length; i++)
079 {
080 final String aName = fnNames[i];
081 final Function function = createFunction(aName);
082 if (function == null)
083 {
084 Log.debug ("There is no such function: " + aName);
085 }
086 else
087 {
088 functions.add(function);
089 }
090 }
091 return (Function[]) functions.toArray(new Function[functions.size()]);
092 }
093
094 public String[] getFunctionNames()
095 {
096 return (String[]) functions.keySet().toArray(new String[functions.size()]);
097 }
098
099 public String[] getFunctionNamesByCategory(final FunctionCategory category)
100 {
101 return (String[]) categoryFunctions.toArray(category, EMPTY_ARRAY);
102 }
103
104 public Function[] getFunctionsByCategory(final FunctionCategory category)
105 {
106 final String[] fnNames = (String[]) categoryFunctions.toArray(category, EMPTY_ARRAY);
107 final ArrayList functions = new ArrayList(fnNames.length);
108 for (int i = 0; i < fnNames.length; i++)
109 {
110 final String aName = fnNames[i];
111 final Function function = createFunction(aName);
112 if (function != null)
113 {
114 functions.add(function);
115 }
116 }
117 return (Function[]) functions.toArray(new Function[functions.size()]);
118 }
119
120 public Function createFunction(final String name)
121 {
122 if (name == null)
123 {
124 throw new NullPointerException();
125 }
126 final String functionClass = (String) functions.get(name.toUpperCase());
127 final Class cachedClass = (Class) cachedFunctions.get(functionClass);
128 if (cachedClass != null)
129 {
130 try
131 {
132 return (Function) cachedClass.newInstance();
133 }
134 catch (Exception e)
135 {
136 return null;
137 }
138 }
139
140 final Function function = (Function) ObjectUtilities.loadAndInstantiate
141 (functionClass, DefaultFunctionRegistry.class, Function.class);
142 if (function == null)
143 {
144 Log.debug ("There is no such function: " + name);
145 }
146 else
147 {
148 cachedFunctions.put(functionClass, function.getClass());
149 }
150 return function;
151 }
152
153 public FunctionDescription getMetaData(final String name)
154 {
155 if (name == null)
156 {
157 throw new NullPointerException();
158 }
159 return (FunctionDescription) functionMetaData.get(name.toUpperCase());
160 }
161
162 public void initialize(final Configuration configuration)
163 {
164 final Iterator functionKeys =
165 configuration.findPropertyKeys(FUNCTIONS_PREFIX);
166 final HashSet categories = new HashSet();
167
168
169 while (functionKeys.hasNext())
170 {
171 final String classKey = (String) functionKeys.next();
172 if (classKey.endsWith(".class") == false)
173 {
174 continue;
175 }
176
177 final String className = configuration.getConfigProperty(classKey);
178 if (className.length() == 0)
179 {
180 continue;
181 }
182 final Object fn = ObjectUtilities.loadAndInstantiate
183 (className, DefaultFunctionRegistry.class, Function.class);
184 if (fn instanceof Function == false)
185 {
186 continue;
187 }
188
189 final Function function = (Function) fn;
190
191 final int endIndex = classKey.length() - ".class".length();
192 final String descrKey = classKey.substring(0, endIndex) + ".description";
193 final String descrClassName = configuration.getConfigProperty(descrKey);
194 final Object descr = ObjectUtilities.loadAndInstantiate
195 (descrClassName, DefaultFunctionRegistry.class, FunctionDescription.class);
196
197 final FunctionDescription description;
198 if (descr instanceof FunctionDescription == false)
199 {
200 description = new DefaultFunctionDescription(function.getCanonicalName());
201 }
202 else
203 {
204 description = (FunctionDescription) descr;
205 }
206
207 final FunctionCategory cat = description.getCategory();
208 categoryFunctions.add(cat, function.getCanonicalName());
209 functionMetaData.put (function.getCanonicalName(), description);
210 functions.put(function.getCanonicalName(), className);
211 categories.add(cat);
212 }
213
214 this.categories = (FunctionCategory[]) categories.toArray(new FunctionCategory[categories.size()]);
215 }
216
217 }