|
1
16 package org.apache.cocoon.components.variables;
17
18 import java.util.ArrayList  ;
19 import java.util.List ;
20
21 import org.apache.avalon.framework.activity.Disposable;
22 import org.apache.avalon.framework.configuration.ConfigurationException;
23 import org.apache.avalon.framework.context.Context;
24 import org.apache.avalon.framework.service.ServiceException;
25 import org.apache.avalon.framework.service.ServiceManager;
26 import org.apache.avalon.framework.service.ServiceSelector;
27 import org.apache.avalon.framework.thread.ThreadSafe;
28 import org.apache.cocoon.components.ContextHelper;
29 import org.apache.cocoon.components.modules.input.InputModule;
30 import org.apache.cocoon.sitemap.PatternException;
31
32
40 public class PreparedVariableResolver
41 extends NOPVariableResolver
42 implements Disposable {
43
44 protected ServiceManager manager;
45 protected ServiceSelector selector;
46 protected Context context;
47
48 protected List items = new ArrayList ();
49
50 static final int LITERAL = -2;
52 static final int THREADSAFE_MODULE = -3;
53 static final int STATEFUL_MODULE = -4;
54
55 private static final Integer LITERAL_OBJ = new Integer (LITERAL);
56 private static final Integer THREADSAFE_MODULE_OBJ = new Integer (THREADSAFE_MODULE);
57 private static final Integer STATEFUL_MODULE_OBJ = new Integer (STATEFUL_MODULE);
58
59 public PreparedVariableResolver(String expr, ServiceManager manager, Context context)
60 throws PatternException {
61
62 super(null);
63 this.expression = expr;
64 this.manager = manager;
65 this.context = context;
66
67 int length = expr.length();
68 int prev = 0;
70 compile : while(prev < length) {
71 int pos = prev;
73 while(pos < length &&
74 (pos = expr.indexOf('{', pos)) != -1 &&
75 (pos != 0 && expr.charAt(pos - 1) == '\\')) {
76 pos++;
77 }
78
79 if (pos >= length || pos == -1) {
80 if (prev < length) {
82 addLiteral(expr.substring(prev));
83 }
84 break compile;
85 }
86
87 pos++;
89
90 if (prev < pos-1) {
92 addLiteral(expr.substring(prev, pos - 1));
93 }
94
95 int end = expr.indexOf('}', pos);
96 if (end == -1) {
97 throw new PatternException("Unmatched '{' in " + expr);
98 }
99
100 int colon = expr.indexOf(':', pos);
101 if (colon != -1 && colon < end) {
102
103 String module = expr.substring(pos, colon);
104 String variable = expr.substring(colon + 1, end);
105
106 addModuleVariable(module, variable);
108 } else {
109 throw new PatternException("Unknown variable format " + expr.substring(pos, end));
110 }
111
112 prev = end + 1;
113 }
114 }
115
116 protected void addLiteral(String litteral) {
117 this.items.add(LITERAL_OBJ);
118 this.items.add(litteral);
119 }
120
121
122 protected void addModuleVariable(String moduleName, String variable) throws PatternException {
123 if (this.selector == null) {
124 try {
125 this.selector = (ServiceSelector)this.manager.lookup(InputModule.ROLE + "Selector");
127 } catch(ServiceException ce) {
128 throw new PatternException("Cannot access input modules selector", ce);
129 }
130 }
131
132 InputModule module;
134 try {
135 module = (InputModule)this.selector.select(moduleName);
136 } catch(ServiceException ce) {
137 throw new PatternException("Cannot get InputModule named '" + moduleName +
138 "' in expression '" + this.expression + "'", ce);
139 }
140
141 if (module instanceof ThreadSafe) {
143 this.items.add(THREADSAFE_MODULE_OBJ);
144 this.items.add(module);
145 this.items.add(variable);
146 } else {
147 this.selector.release(module);
149 this.items.add(STATEFUL_MODULE_OBJ);
150 this.items.add(moduleName);
151 this.items.add(variable);
152 }
153 }
154
155 public String resolve()
156 throws PatternException {
157
158 StringBuffer result = new StringBuffer ();
159
160 for (int i = 0; i < this.items.size(); i++) {
161 int type = ((Integer )this.items.get(i)).intValue();
162
163 switch(type) {
164 case LITERAL :
165 result.append(items.get(++i));
166 break;
167
168 case THREADSAFE_MODULE :
169 {
170 InputModule module = (InputModule)items.get(++i);
171 String variable = (String )items.get(++i);
172
173 try {
174 Object value = module.getAttribute(variable, null, ContextHelper.getObjectModel(this.context));
175
176 if (value != null) {
177 result.append(value);
178 }
179
180 } catch(ConfigurationException confEx) {
181 throw new PatternException("Cannot get variable '" + variable +
182 "' in expression '" + this.expression + "'", confEx);
183 }
184 }
185 break;
186
187 case STATEFUL_MODULE :
188 {
189 InputModule module = null;
190 String moduleName = (String )items.get(++i);
191 String variableName = (String )items.get(++i);
192 try {
193 module = (InputModule)this.selector.select(moduleName);
194
195 Object value = module.getAttribute(variableName, null, ContextHelper.getObjectModel(this.context));
196
197 if (value != null) {
198 result.append(value);
199 }
200
201 } catch(ServiceException compEx) {
202 throw new PatternException("Cannot get module '" + moduleName +
203 "' in expression '" + this.expression + "'", compEx);
204
205 } catch(ConfigurationException confEx) {
206 throw new PatternException("Cannot get variable '" + variableName +
207 "' in expression '" + this.expression + "'", confEx);
208
209 } finally {
210 this.selector.release(module);
211 }
212 }
213 break;
214 }
215 }
216
217 return result.toString();
218
219 }
220
221
224 public void dispose() {
225 if (this.selector != null) {
226 for (int i = 0; i < this.items.size(); i++) {
227 int type = ((Integer ) this.items.get(i)).intValue();
228
229 switch (type) {
230 case LITERAL:
231 i++; break;
233
234 case THREADSAFE_MODULE:
235 i++; this.selector.release(this.items.get(i));
237 i++; break;
239
240 case STATEFUL_MODULE:
241 i += 2; break;
243
244 default:
245 }
246 }
247 this.manager.release(this.selector);
248 this.selector = null;
249 this.manager = null;
250 }
251 }
252 }
253 |
Popular Tags |
Java API By Example, From Geeks To Geeks.