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1
19
20 package org.apache.cayenne.reflect;
21
22 import java.beans.BeanInfo  ;
23 import java.beans.IntrospectionException ;
24 import java.beans.Introspector ;
25 import java.beans.PropertyDescriptor ;
26 import java.lang.reflect.InvocationTargetException ;
27 import java.lang.reflect.Method ;
28 import java.util.Map ;
29 import java.util.StringTokenizer ;
30
31 import org.apache.cayenne.CayenneRuntimeException;
32 import org.apache.cayenne.map.Entity;
33 import org.apache.cayenne.util.Util;
34
35
44 public class PropertyUtils {
45
46
50 public static Object getProperty(Object object, String nestedPropertyName)
51 throws CayenneRuntimeException {
52
53 if (object == null) {
54 throw new IllegalArgumentException ("Null object.");
55 }
56
57 if (Util.isEmptyString(nestedPropertyName)) {
58 throw new IllegalArgumentException ("Null or empty property name.");
59 }
60
61 StringTokenizer path = new StringTokenizer (
62 nestedPropertyName,
63 Entity.PATH_SEPARATOR);
64 int len = path.countTokens();
65
66 Object value = object;
67 String pathSegment = null;
68
69 try {
70 for (int i = 1; i <= len; i++) {
71 pathSegment = path.nextToken();
72
73 if (value == null) {
74 throw new CayenneRuntimeException(
76 "Null value in the middle of the path");
77 }
78
79 value = getSimpleProperty(value, pathSegment);
80 }
81
82 return value;
83 }
84 catch (Exception e) {
85 String objectType = value != null ? value.getClass().getName() : "<null>";
86 throw new CayenneRuntimeException("Error reading property segment '"
87 + pathSegment
88 + "' in path '"
89 + nestedPropertyName
90 + "' for type "
91 + objectType, e);
92 }
93 }
94
95
101 public static void setProperty(Object object, String nestedPropertyName, Object value)
102 throws CayenneRuntimeException {
103
104 if (object == null) {
105 throw new IllegalArgumentException ("Null object.");
106 }
107
108 if (Util.isEmptyString(nestedPropertyName)) {
109 throw new IllegalArgumentException ("Null or invalid property name.");
110 }
111
112 int dot = nestedPropertyName.lastIndexOf(Entity.PATH_SEPARATOR);
113 String lastSegment;
114 if (dot > 0) {
115 lastSegment = nestedPropertyName.substring(dot + 1);
116 String pathSegment = nestedPropertyName.substring(0, dot);
117 object = getProperty(object, pathSegment);
118
119 if (object == null) {
120 throw new IllegalArgumentException (
121 "Null object at the end of the segment '" + pathSegment + "'");
122 }
123 }
124 else {
125 lastSegment = nestedPropertyName;
126 }
127
128 try {
129 setSimpleProperty(object, lastSegment, value);
130 }
131 catch (Exception e) {
132 throw new CayenneRuntimeException("Error setting property segment '"
133 + lastSegment
134 + "' in path '"
135 + nestedPropertyName
136 + "'", e);
137 }
138
139 }
140
141 static Object getSimpleProperty(Object object, String pathSegment)
142 throws IntrospectionException , IllegalArgumentException ,
143 IllegalAccessException , InvocationTargetException {
144
145 PropertyDescriptor descriptor = getPropertyDescriptor(
146 object.getClass(),
147 pathSegment);
148
149 if (descriptor != null) {
150 Method reader = descriptor.getReadMethod();
151
152 if (reader == null) {
153 throw new IntrospectionException ("Unreadable property '"
154 + pathSegment
155 + "'");
156 }
157
158 return reader.invoke(object, null);
159 }
160 else if (object instanceof Map ) {
163 return ((Map ) object).get(pathSegment);
164 }
165 else {
166 throw new IntrospectionException ("No property '"
167 + pathSegment
168 + "' found in class "
169 + object.getClass().getName());
170 }
171 }
172
173 static void setSimpleProperty(Object object, String pathSegment, Object value)
174 throws IntrospectionException , IllegalArgumentException ,
175 IllegalAccessException , InvocationTargetException {
176
177 PropertyDescriptor descriptor = getPropertyDescriptor(
178 object.getClass(),
179 pathSegment);
180
181 if (descriptor != null) {
182 Method writer = descriptor.getWriteMethod();
183
184 if (writer == null) {
185 throw new IntrospectionException ("Unwritable property '"
186 + pathSegment
187 + "'");
188 }
189
190
192 value = ConverterFactory.factory
193 .getConverter(descriptor.getPropertyType())
194 .convert(value, descriptor.getPropertyType());
195
196 writer.invoke(object, new Object [] {
198 value
199 });
200 }
201 else if (object instanceof Map ) {
204 ((Map ) object).put(pathSegment, value);
205 }
206 else {
207 throw new IntrospectionException ("No property '"
208 + pathSegment
209 + "' found in class "
210 + object.getClass().getName());
211 }
212 }
213
214 static PropertyDescriptor getPropertyDescriptor(Class beanClass, String propertyName)
215 throws IntrospectionException {
216 BeanInfo info = Introspector.getBeanInfo(beanClass);
219 PropertyDescriptor [] descriptors = info.getPropertyDescriptors();
220
221 for (int i = 0; i < descriptors.length; i++) {
222 if (propertyName.equals(descriptors[i].getName())) {
223 return descriptors[i];
224 }
225 }
226
227 return null;
228 }
229
230
233 static Class normalizeType(Class type) {
234 if (type.isPrimitive()) {
235
236 String className = type.getName();
237 if ("byte".equals(className)) {
238 return Byte .class;
239 }
240 else if ("int".equals(className)) {
241 return Integer .class;
242 }
243 else if ("short".equals(className)) {
244 return Short .class;
245 }
246 else if ("char".equals(className)) {
247 return Character .class;
248 }
249 else if ("double".equals(className)) {
250 return Double .class;
251 }
252 else if ("float".equals(className)) {
253 return Float .class;
254 }
255 else if ("boolean".equals(className)) {
256 return Boolean .class;
257 }
258 }
259
260 return type;
261 }
262
263
267 static Object defaultNullValueForType(Class type) {
268 if (type.isPrimitive()) {
269
270 String className = type.getName();
271 if ("byte".equals(className)) {
272 return new Byte ((byte) 0);
273 }
274 else if ("int".equals(className)) {
275 return new Integer (0);
276 }
277 else if ("short".equals(className)) {
278 return new Short ((short) 0);
279 }
280 else if ("char".equals(className)) {
281 return new Character ((char) 0);
282 }
283 else if ("double".equals(className)) {
284 return new Double (0d);
285 }
286 else if ("float".equals(className)) {
287 return new Float (0f);
288 }
289 else if ("boolean".equals(className)) {
290 return Boolean.FALSE;
291 }
292 }
293
294 return null;
295 }
296
297 private PropertyUtils() {
298 super();
299 }
300 }
301 |
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