001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.kahadb.util;
018
019 import java.beans.PropertyEditor;
020 import java.beans.PropertyEditorManager;
021 import java.lang.reflect.Field;
022 import java.lang.reflect.Method;
023 import java.lang.reflect.Modifier;
024 import java.net.URI;
025 import java.net.URISyntaxException;
026 import java.util.Arrays;
027 import java.util.HashMap;
028 import java.util.Iterator;
029 import java.util.LinkedHashMap;
030 import java.util.Map;
031 import java.util.Set;
032 import java.util.Map.Entry;
033
034 public final class IntrospectionSupport {
035
036 private IntrospectionSupport() {
037 }
038
039 public static boolean getProperties(Object target, Map props, String optionPrefix) {
040
041 boolean rc = false;
042 if (target == null) {
043 throw new IllegalArgumentException("target was null.");
044 }
045 if (props == null) {
046 throw new IllegalArgumentException("props was null.");
047 }
048
049 if (optionPrefix == null) {
050 optionPrefix = "";
051 }
052
053 Class clazz = target.getClass();
054 Method[] methods = clazz.getMethods();
055 for (int i = 0; i < methods.length; i++) {
056 Method method = methods[i];
057 String name = method.getName();
058 Class type = method.getReturnType();
059 Class params[] = method.getParameterTypes();
060 if ((name.startsWith("is") || name.startsWith("get")) && params.length == 0 && type != null && isSettableType(type)) {
061
062 try {
063
064 Object value = method.invoke(target, new Object[] {});
065 if (value == null) {
066 continue;
067 }
068
069 String strValue = convertToString(value, type);
070 if (strValue == null) {
071 continue;
072 }
073 if (name.startsWith("get")) {
074 name = name.substring(3, 4).toLowerCase()
075 + name.substring(4);
076 } else {
077 name = name.substring(2, 3).toLowerCase()
078 + name.substring(3);
079 }
080 props.put(optionPrefix + name, strValue);
081 rc = true;
082
083 } catch (Throwable ignore) {
084 ignore.printStackTrace();
085 }
086
087 }
088 }
089
090 return rc;
091 }
092
093 public static boolean setProperties(Object target, Map props, String optionPrefix) {
094 boolean rc = false;
095 if (target == null) {
096 throw new IllegalArgumentException("target was null.");
097 }
098 if (props == null) {
099 throw new IllegalArgumentException("props was null.");
100 }
101
102 for (Iterator<String> iter = props.keySet().iterator(); iter.hasNext();) {
103 String name = iter.next();
104 if (name.startsWith(optionPrefix)) {
105 Object value = props.get(name);
106 name = name.substring(optionPrefix.length());
107 if (setProperty(target, name, value)) {
108 iter.remove();
109 rc = true;
110 }
111 }
112 }
113 return rc;
114 }
115
116 public static Map<String, Object> extractProperties(Map props, String optionPrefix) {
117 if (props == null) {
118 throw new IllegalArgumentException("props was null.");
119 }
120
121 HashMap<String, Object> rc = new HashMap<String, Object>(props.size());
122
123 for (Iterator iter = props.keySet().iterator(); iter.hasNext();) {
124 String name = (String)iter.next();
125 if (name.startsWith(optionPrefix)) {
126 Object value = props.get(name);
127 name = name.substring(optionPrefix.length());
128 rc.put(name, value);
129 iter.remove();
130 }
131 }
132
133 return rc;
134 }
135
136 public static boolean setProperties(Object target, Map props) {
137 boolean rc = false;
138
139 if (target == null) {
140 throw new IllegalArgumentException("target was null.");
141 }
142 if (props == null) {
143 throw new IllegalArgumentException("props was null.");
144 }
145
146 for (Iterator iter = props.entrySet().iterator(); iter.hasNext();) {
147 Map.Entry entry = (Entry)iter.next();
148 if (setProperty(target, (String)entry.getKey(), entry.getValue())) {
149 iter.remove();
150 rc = true;
151 }
152 }
153
154 return rc;
155 }
156
157 public static boolean setProperty(Object target, String name, Object value) {
158 try {
159 Class clazz = target.getClass();
160 Method setter = findSetterMethod(clazz, name);
161 if (setter == null) {
162 return false;
163 }
164
165 // If the type is null or it matches the needed type, just use the
166 // value directly
167 if (value == null || value.getClass() == setter.getParameterTypes()[0]) {
168 setter.invoke(target, new Object[] {value});
169 } else {
170 // We need to convert it
171 setter.invoke(target, new Object[] {convert(value, setter.getParameterTypes()[0])});
172 }
173 return true;
174 } catch (Throwable ignore) {
175 return false;
176 }
177 }
178
179 private static Object convert(Object value, Class type) throws URISyntaxException {
180 PropertyEditor editor = PropertyEditorManager.findEditor(type);
181 if (editor != null) {
182 editor.setAsText(value.toString());
183 return editor.getValue();
184 }
185 if (type == URI.class) {
186 return new URI(value.toString());
187 }
188 return null;
189 }
190
191 private static String convertToString(Object value, Class type) throws URISyntaxException {
192 PropertyEditor editor = PropertyEditorManager.findEditor(type);
193 if (editor != null) {
194 editor.setValue(value);
195 return editor.getAsText();
196 }
197 if (type == URI.class) {
198 return ((URI)value).toString();
199 }
200 return null;
201 }
202
203 private static Method findSetterMethod(Class clazz, String name) {
204 // Build the method name.
205 name = "set" + name.substring(0, 1).toUpperCase() + name.substring(1);
206 Method[] methods = clazz.getMethods();
207 for (int i = 0; i < methods.length; i++) {
208 Method method = methods[i];
209 Class params[] = method.getParameterTypes();
210 if (method.getName().equals(name) && params.length == 1 ) {
211 return method;
212 }
213 }
214 return null;
215 }
216
217 private static boolean isSettableType(Class clazz) {
218 if (PropertyEditorManager.findEditor(clazz) != null) {
219 return true;
220 }
221 if (clazz == URI.class) {
222 return true;
223 }
224 if (clazz == Boolean.class) {
225 return true;
226 }
227 return false;
228 }
229
230 public static String toString(Object target) {
231 return toString(target, Object.class);
232 }
233
234 public static String toString(Object target, Class stopClass) {
235 LinkedHashMap<String, Object> map = new LinkedHashMap<String, Object>();
236 addFields(target, target.getClass(), stopClass, map);
237 StringBuffer buffer = new StringBuffer(simpleName(target.getClass()));
238 buffer.append(" {");
239 Set entrySet = map.entrySet();
240 boolean first = true;
241 for (Iterator iter = entrySet.iterator(); iter.hasNext();) {
242 Map.Entry entry = (Map.Entry)iter.next();
243 if (first) {
244 first = false;
245 } else {
246 buffer.append(", ");
247 }
248 buffer.append(entry.getKey());
249 buffer.append(" = ");
250 appendToString(buffer, entry.getValue());
251 }
252 buffer.append("}");
253 return buffer.toString();
254 }
255
256 protected static void appendToString(StringBuffer buffer, Object value) {
257 buffer.append(value);
258 }
259
260 public static String simpleName(Class clazz) {
261 String name = clazz.getName();
262 int p = name.lastIndexOf(".");
263 if (p >= 0) {
264 name = name.substring(p + 1);
265 }
266 return name;
267 }
268
269 private static void addFields(Object target, Class startClass, Class<Object> stopClass, LinkedHashMap<String, Object> map) {
270
271 if (startClass != stopClass) {
272 addFields(target, startClass.getSuperclass(), stopClass, map);
273 }
274
275 Field[] fields = startClass.getDeclaredFields();
276 for (int i = 0; i < fields.length; i++) {
277 Field field = fields[i];
278 if (Modifier.isStatic(field.getModifiers()) || Modifier.isTransient(field.getModifiers())
279 || Modifier.isPrivate(field.getModifiers())) {
280 continue;
281 }
282
283 try {
284 field.setAccessible(true);
285 Object o = field.get(target);
286 if (o != null && o.getClass().isArray()) {
287 try {
288 o = Arrays.asList((Object[])o);
289 } catch (Throwable e) {
290 }
291 }
292 map.put(field.getName(), o);
293 } catch (Throwable e) {
294 e.printStackTrace();
295 }
296 }
297
298 }
299
300 }