|
1
18 package org.apache.beehive.netui.script.el.tokens;
19
20 import java.lang.reflect.Array  ;
21 import java.lang.reflect.Field ;
22 import java.lang.reflect.Method ;
23 import java.util.List ;
24 import java.util.Map ;
25
26 import org.apache.beehive.netui.util.internal.cache.PropertyCache;
27 import org.apache.beehive.netui.util.logging.Logger;
28 import org.apache.beehive.netui.script.el.util.ParseUtils;
29
30
33 public abstract class ExpressionToken {
34
35 private static final Logger LOGGER = Logger.getInstance(ArrayIndexToken.class);
36
37 private static final PropertyCache PROPERTY_CACHE = new PropertyCache();
38
39 public abstract Object evaluate(Object value);
40
41 public abstract void update(Object root, Object newValue);
42
43 public abstract String getTokenString();
44
45
46
51 protected final Object mapLookup(Map map, Object identifier) {
52 if(LOGGER.isDebugEnabled())
53 LOGGER.debug("mapLookup: " + identifier);
54 return map.get(identifier);
55 }
56
57 protected final Object beanLookup(Object bean, Object identifier) {
58 if(LOGGER.isDebugEnabled())
59 LOGGER.debug("beanLookup: " + identifier);
60
61 return ParseUtils.getProperty(bean, identifier.toString(), PROPERTY_CACHE);
62 }
63
64 protected final Object listLookup(List list, int index) {
65 if(LOGGER.isDebugEnabled())
66 LOGGER.debug("listLookup: " + index);
67
68 return list.get(index);
69 }
70
71 protected final Object arrayLookup(Object array, int index) {
72 if(LOGGER.isDebugEnabled())
73 LOGGER.debug("arrayLookup: " + index);
74
75 return Array.get(array, index);
76 }
77
78 protected final void mapUpdate(Map map, Object identifier, Object value) {
79 Object converted = value;
80
81 Object o = map.get(identifier);
82 if(o != null) {
83 Class type = o.getClass();
84 value = ParseUtils.convertType(value, type);
85 }
86
87 map.put(identifier, value);
88 }
89
90 protected final void arrayUpdate(Object array, int index, Object value) {
91 Object converted = value;
92
93 Class elementType = array.getClass().getComponentType();
94 if(!elementType.isAssignableFrom(value.getClass())) {
95 converted = ParseUtils.convertType(value, elementType);
96 }
97
98 try {
99 Array.set(array, index, converted);
100 } catch(Exception e) {
101 String msg = "An error occurred setting a value at index \"" + index + "\" on an array with component types \"" +
102 elementType + "\". Cause: " + e.toString();
103
104 if(LOGGER.isErrorEnabled()) LOGGER.error(msg);
105 throw new RuntimeException (msg);
106 }
107 }
108
109 protected final void listUpdate(List list, int index, Object value) {
110 Object converted = value;
111
112 if(list.size() > index) {
113 Object o = list.get(index);
114 if(o != null) {
116 Class itemType = o.getClass();
117 converted = ParseUtils.convertType(value, itemType);
118 }
119
120 list.set(index, value);
121 } else {
122 String msg = "An error occurred setting a value at index \"" + index + "\" because the list is " +
143 (list != null ? (" of size " + list.size()) : "null") + ". " +
144 "Be sure to allocate enough items in the List to accomodate any updates which may occur against the list.";
145
146 if(LOGGER.isErrorEnabled()) LOGGER.error(msg);
147
148 throw new RuntimeException (msg);
149 }
150 }
151
152 protected final void beanUpdate(Object bean, Object identifier, Object value) {
153 if(LOGGER.isDebugEnabled()) LOGGER.debug("Update \"" + bean + "\" type property \"" + identifier + "\"");
154
155 String id = identifier.toString();
156 Class beanType = bean.getClass();
157 Class propType = PROPERTY_CACHE.getPropertyType(beanType, id);
158 if(propType != null) {
159 try {
160 if(java.util.List .class.isAssignableFrom(propType)) {
161 Method lm = PROPERTY_CACHE.getPropertyGetter(beanType, id);
162 if(lm != null) {
163 List list = (List )lm.invoke(bean, (Object [])null);
164 applyValuesToList(value, list);
165 return;
166 }
167 } else {
168 Method m = PROPERTY_CACHE.getPropertySetter(beanType, id);
169
170 if(m != null) {
171 if(LOGGER.isDebugEnabled())
172 LOGGER.debug("Apply value to property via method: " + m);
173
174 Class targetType = m.getParameterTypes()[0];
175 Object converted = ParseUtils.convertType(value, targetType);
176
177 m.invoke(bean, new Object []{converted});
178 return;
179 }
180 }
181 } catch(Exception e) {
182 String msg = "Could not update proprety named \"" + id + "\" on bean of type \"" + beanType + "\". Cause: " + e;
183 if(LOGGER.isErrorEnabled())
184 LOGGER.error(msg, e);
185 throw new RuntimeException (msg, e);
186 }
187 }
188
189 String msg = "Could not update expression because a public JavaBean setter for the property \"" + identifier + "\" could not be found.";
190 LOGGER.error(msg);
191 throw new RuntimeException (msg);
192 }
193
194 protected final int parseIndex(String identifier) {
195 try {
196 return Integer.parseInt(identifier);
197 } catch(Exception e) {
198 String msg = "Error performing an array look-up with the index \"" + identifier + "\". Cause: " + e;
199
200 if(LOGGER.isDebugEnabled())
201 LOGGER.debug(msg, e);
202
203 throw new RuntimeException (msg, e);
204 }
205 }
206
207 private static final void applyValuesToList(Object value, List list) {
208 if(list == null) {
209 String msg = "Can not add a value to a null java.util.List";
210 LOGGER.error(msg);
211 throw new RuntimeException (msg);
212 }
213
214 if(value instanceof String []) {
215 String [] ary = (String [])value;
216 for(int i = 0; i < ary.length; i++) {
217 list.add(ary[i]);
218 }
219 } else if(value instanceof String ) {
220 list.add(value);
221 }
222 else list.add(value);
224 }
225 }
226 |
Popular Tags |
Java API By Example, From Geeks To Geeks.