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.camel.util;
018
019 import java.beans.PropertyEditor;
020 import java.beans.PropertyEditorManager;
021 import java.lang.reflect.Field;
022 import java.lang.reflect.InvocationTargetException;
023 import java.lang.reflect.Method;
024 import java.lang.reflect.Modifier;
025 import java.net.URI;
026 import java.net.URISyntaxException;
027 import java.util.Arrays;
028 import java.util.HashMap;
029 import java.util.Iterator;
030 import java.util.LinkedHashMap;
031 import java.util.LinkedHashSet;
032 import java.util.Map;
033 import java.util.Set;
034
035 import org.apache.camel.NoTypeConversionAvailableException;
036 import org.apache.camel.TypeConverter;
037 import org.apache.commons.logging.Log;
038 import org.apache.commons.logging.LogFactory;
039
040 /**
041 * Helper for introspections of beans.
042 */
043 public final class IntrospectionSupport {
044
045 private static final transient Log LOG = LogFactory.getLog(IntrospectionSupport.class);
046
047 /**
048 * Utility classes should not have a public constructor.
049 */
050 private IntrospectionSupport() {
051 }
052
053 /**
054 * Copies the properties from the source to the target
055 * @param source source object
056 * @param target target object
057 * @param optionPrefix optional option preifx (can be null)
058 * @return true if properties is copied, false if something went wrong
059 */
060 public static boolean copyProperties(Object source, Object target, String optionPrefix) {
061 Map properties = new LinkedHashMap();
062 if (!getProperties(source, properties, optionPrefix)) {
063 return false;
064 }
065 try {
066 return setProperties(target, properties, optionPrefix);
067 } catch (Exception e) {
068 LOG.debug("Can not copy properties to target: " + target, e);
069 return false;
070 }
071 }
072
073 @SuppressWarnings("unchecked")
074 public static boolean getProperties(Object target, Map properties, String optionPrefix) {
075 ObjectHelper.notNull(target, "target");
076 ObjectHelper.notNull(properties, "properties");
077 boolean rc = false;
078 if (optionPrefix == null) {
079 optionPrefix = "";
080 }
081
082 Class clazz = target.getClass();
083 Method[] methods = clazz.getMethods();
084 for (Method method : methods) {
085 String name = method.getName();
086 Class type = method.getReturnType();
087 Class params[] = method.getParameterTypes();
088 if (name.startsWith("get") && params.length == 0 && type != null && isSettableType(type)) {
089 try {
090 Object value = method.invoke(target);
091 if (value == null) {
092 continue;
093 }
094
095 String strValue = convertToString(value, type);
096 if (strValue == null) {
097 continue;
098 }
099
100 name = name.substring(3, 4).toLowerCase() + name.substring(4);
101 properties.put(optionPrefix + name, strValue);
102 rc = true;
103 } catch (Exception ignore) {
104 // ignore
105 }
106 }
107 }
108
109 return rc;
110 }
111
112 public static boolean hasProperties(Map properties, String optionPrefix) {
113 ObjectHelper.notNull(properties, "properties");
114
115 if (ObjectHelper.isNotEmpty(optionPrefix)) {
116 for (Object o : properties.keySet()) {
117 String name = (String) o;
118 if (name.startsWith(optionPrefix)) {
119 return true;
120 }
121 }
122 // no parameters with this prefix
123 return false;
124 } else {
125 return !properties.isEmpty();
126 }
127 }
128
129 public static Object getProperty(Object target, String property) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
130 ObjectHelper.notNull(target, "target");
131 ObjectHelper.notNull(property, "property");
132
133 property = property.substring(0, 1).toUpperCase() + property.substring(1);
134
135 Class clazz = target.getClass();
136 Method method = getPropertyGetter(clazz, property);
137 return method.invoke(target);
138 }
139
140 public static Method getPropertyGetter(Class type, String propertyName) throws NoSuchMethodException {
141 return type.getMethod("get" + ObjectHelper.capitalize(propertyName));
142 }
143
144 public static boolean setProperties(Object target, Map properties, String optionPrefix) throws Exception {
145 ObjectHelper.notNull(target, "target");
146 ObjectHelper.notNull(properties, "properties");
147 boolean rc = false;
148
149 for (Iterator iter = properties.keySet().iterator(); iter.hasNext();) {
150 String name = (String)iter.next();
151 if (name.startsWith(optionPrefix)) {
152 Object value = properties.get(name);
153 name = name.substring(optionPrefix.length());
154 if (setProperty(target, name, value)) {
155 iter.remove();
156 rc = true;
157 }
158 }
159 }
160 return rc;
161 }
162
163 @SuppressWarnings("unchecked")
164 public static Map extractProperties(Map properties, String optionPrefix) {
165 ObjectHelper.notNull(properties, "properties");
166
167 HashMap rc = new LinkedHashMap(properties.size());
168
169 for (Iterator iter = properties.keySet().iterator(); iter.hasNext();) {
170 String name = (String)iter.next();
171 if (name.startsWith(optionPrefix)) {
172 Object value = properties.get(name);
173 name = name.substring(optionPrefix.length());
174 rc.put(name, value);
175 iter.remove();
176 }
177 }
178
179 return rc;
180 }
181
182 public static boolean setProperties(TypeConverter typeConverter, Object target, Map properties) throws Exception {
183 ObjectHelper.notNull(target, "target");
184 ObjectHelper.notNull(properties, "properties");
185 boolean rc = false;
186
187 for (Iterator iter = properties.entrySet().iterator(); iter.hasNext();) {
188 Map.Entry entry = (Map.Entry)iter.next();
189 if (setProperty(typeConverter, target, (String)entry.getKey(), entry.getValue())) {
190 iter.remove();
191 rc = true;
192 }
193 }
194
195 return rc;
196 }
197
198 public static boolean setProperties(Object target, Map props) throws Exception {
199 return setProperties(null, target, props);
200 }
201
202 public static boolean setProperty(TypeConverter typeConverter, Object target, String name, Object value) throws Exception {
203 try {
204 Class clazz = target.getClass();
205 // find candidates of setter methods as there can be overloaded setters
206 Set<Method> setters = findSetterMethods(typeConverter, clazz, name, value);
207 if (setters.isEmpty()) {
208 return false;
209 }
210
211 // loop and execute the best setter method
212 Exception typeConvertionFailed = null;
213 for (Method setter : setters) {
214 // If the type is null or it matches the needed type, just use the value directly
215 if (value == null || setter.getParameterTypes()[0].isAssignableFrom(value.getClass())) {
216 setter.invoke(target, value);
217 return true;
218 } else {
219 // We need to convert it
220 try {
221 // ignore exceptions as there could be another setter method where we could type convert successfully
222 Object convertedValue = convert(typeConverter, setter.getParameterTypes()[0], value);
223 setter.invoke(target, convertedValue);
224 return true;
225 } catch (NoTypeConversionAvailableException e) {
226 typeConvertionFailed = e;
227 } catch (IllegalArgumentException e) {
228 typeConvertionFailed = e;
229 }
230 if (LOG.isTraceEnabled()) {
231 LOG.trace("Setter \"" + setter + "\" with parameter type \""
232 + setter.getParameterTypes()[0] + "\" could not be used for type conversions of " + value);
233 }
234 }
235 }
236 // we did not find a setter method to use, and if we did try to use a type converter then throw
237 // this kind of exception as the caused by will hint this error
238 if (typeConvertionFailed != null) {
239 throw new IllegalArgumentException("Could not find a suitable setter for property: " + name
240 + " as there isn't a setter method with same type: " + value.getClass().getCanonicalName()
241 + " nor type conversion possible: " + typeConvertionFailed.getMessage());
242 } else {
243 return false;
244 }
245 } catch (InvocationTargetException e) {
246 // lets unwrap the exception
247 Throwable throwable = e.getCause();
248 if (throwable instanceof Exception) {
249 Exception exception = (Exception)throwable;
250 throw exception;
251 } else {
252 Error error = (Error)throwable;
253 throw error;
254 }
255 }
256 }
257
258 public static boolean setProperty(Object target, String name, Object value) throws Exception {
259 return setProperty(null, target, name, value);
260 }
261
262 @SuppressWarnings("unchecked")
263 private static Object convert(TypeConverter typeConverter, Class type, Object value) throws URISyntaxException {
264 if (typeConverter != null) {
265 return typeConverter.convertTo(type, value);
266 }
267 PropertyEditor editor = PropertyEditorManager.findEditor(type);
268 if (editor != null) {
269 editor.setAsText(value.toString());
270 return editor.getValue();
271 }
272 if (type == URI.class) {
273 return new URI(value.toString());
274 }
275 return null;
276 }
277
278 private static String convertToString(Object value, Class type) throws URISyntaxException {
279 PropertyEditor editor = PropertyEditorManager.findEditor(type);
280 if (editor != null) {
281 editor.setValue(value);
282 return editor.getAsText();
283 }
284 if (type == URI.class) {
285 return value.toString();
286 }
287 return null;
288 }
289
290 private static Set<Method> findSetterMethods(TypeConverter typeConverter, Class clazz, String name, Object value) {
291 Set<Method> candidates = new LinkedHashSet<Method>();
292
293 // Build the method name.
294 name = "set" + ObjectHelper.capitalize(name);
295 while (clazz != Object.class) {
296 // Since Object.class.isInstance all the objects,
297 // here we just make sure it will be add to the bottom of the set.
298 Method objectSetMethod = null;
299 Method[] methods = clazz.getMethods();
300 for (Method method : methods) {
301 Class params[] = method.getParameterTypes();
302 if (method.getName().equals(name) && params.length == 1) {
303 Class paramType = params[0];
304 if (paramType.equals(Object.class)) {
305 objectSetMethod = method;
306 } else if (typeConverter != null || isSettableType(paramType) || paramType.isInstance(value)) {
307 candidates.add(method);
308 }
309 }
310 }
311 if (objectSetMethod != null) {
312 candidates.add(objectSetMethod);
313 }
314 clazz = clazz.getSuperclass();
315 }
316
317 if (candidates.isEmpty()) {
318 return candidates;
319 } else if (candidates.size() == 1) {
320 // only one
321 return candidates;
322 } else {
323 // find the best match if possible
324 if (LOG.isTraceEnabled()) {
325 LOG.trace("Found " + candidates.size() + " suitable setter methods for setting " + name);
326 }
327 // prefer to use the one with the same instance if any exists
328 for (Method method : candidates) {
329 if (method.getParameterTypes()[0].isInstance(value)) {
330 if (LOG.isTraceEnabled()) {
331 LOG.trace("Method " + method + " is the best candidate as it has parameter with same instance type");
332 }
333 // retain only this method in the answer
334 candidates.clear();
335 candidates.add(method);
336 return candidates;
337 }
338 }
339 // fallback to return what we have found as candidates so far
340 return candidates;
341 }
342 }
343
344 private static boolean isSettableType(Class clazz) {
345 if (PropertyEditorManager.findEditor(clazz) != null) {
346 return true;
347 }
348 if (clazz == URI.class) {
349 return true;
350 }
351 if (clazz == Boolean.class) {
352 return true;
353 }
354 return false;
355 }
356
357 public static String toString(Object target) {
358 return toString(target, Object.class);
359 }
360
361 public static String toString(Object target, Class stopClass) {
362 LinkedHashMap map = new LinkedHashMap();
363 addFields(target, target.getClass(), stopClass, map);
364 StringBuffer buffer = new StringBuffer(simpleName(target.getClass()));
365 buffer.append(" {");
366 Set entrySet = map.entrySet();
367 boolean first = true;
368 for (Iterator iter = entrySet.iterator(); iter.hasNext();) {
369 Map.Entry entry = (Map.Entry)iter.next();
370 if (first) {
371 first = false;
372 } else {
373 buffer.append(", ");
374 }
375 buffer.append(entry.getKey());
376 buffer.append(" = ");
377 appendToString(buffer, entry.getValue());
378 }
379 buffer.append("}");
380 return buffer.toString();
381 }
382
383 protected static void appendToString(StringBuffer buffer, Object value) {
384 buffer.append(value);
385 }
386
387 public static String simpleName(Class clazz) {
388 String name = clazz.getName();
389 int p = name.lastIndexOf(".");
390 if (p >= 0) {
391 name = name.substring(p + 1);
392 }
393 return name;
394 }
395
396 @SuppressWarnings("unchecked")
397 private static void addFields(Object target, Class startClass, Class stopClass, LinkedHashMap map) {
398 if (startClass != stopClass) {
399 addFields(target, startClass.getSuperclass(), stopClass, map);
400 }
401
402 Field[] fields = startClass.getDeclaredFields();
403 for (Field field : fields) {
404 if (Modifier.isStatic(field.getModifiers()) || Modifier.isTransient(field.getModifiers())
405 || Modifier.isPrivate(field.getModifiers())) {
406 continue;
407 }
408
409 try {
410 field.setAccessible(true);
411 Object o = field.get(target);
412 if (o != null && o.getClass().isArray()) {
413 try {
414 o = Arrays.asList((Object[])o);
415 } catch (Throwable e) {
416 // ignore
417 }
418 }
419 map.put(field.getName(), o);
420 } catch (Throwable e) {
421 throw ObjectHelper.wrapRuntimeCamelException(e);
422 }
423 }
424 }
425
426 }