File: ELContext.java

package info (click to toggle)
tomcat8 8.5.11-1~bpo7%2B1
  • links: PTS, VCS
  • area: main
  • in suites: wheezy-backports-sloppy
  • size: 33,884 kB
  • sloc: java: 303,877; xml: 47,894; jsp: 3,257; sh: 1,390; perl: 269; makefile: 33
file content (306 lines) | stat: -rw-r--r-- 8,935 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package javax.el;

import java.util.ArrayList;
import java.util.Deque;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Objects;

public abstract class ELContext {

    private Locale locale;

    private Map<Class<?>, Object> map;

    private boolean resolved;

    private ImportHandler importHandler = null;

    private List<EvaluationListener> listeners = new ArrayList<>();

    private Deque<Map<String,Object>> lambdaArguments = new LinkedList<>();

    public ELContext() {
        this.resolved = false;
    }

    public void setPropertyResolved(boolean resolved) {
        this.resolved = resolved;
    }

    /**
     * Mark the given property as resolved and notfy any interested listeners.
     *
     * @param base     The base object on which the property was found
     * @param property The property that was resolved
     *
     * @since EL 3.0
     */
    public void setPropertyResolved(Object base, Object property) {
        setPropertyResolved(true);
        notifyPropertyResolved(base, property);
    }

    public boolean isPropertyResolved() {
        return this.resolved;
    }

    // Can't use Class<?> because API needs to match specification
    /**
     * Add an object to this EL context under the given key.
     *
     * @param key           The key under which to store the object
     * @param contextObject The object to add
     *
     * @throws NullPointerException
     *              If the supplied key or context is <code>null</code>
     */
    public void putContext(@SuppressWarnings("rawtypes") Class key,
            Object contextObject) {
        Objects.requireNonNull(key);
        Objects.requireNonNull(contextObject);

        if (this.map == null) {
            this.map = new HashMap<>();
        }

        this.map.put(key, contextObject);
    }

    // Can't use Class<?> because API needs to match specification
    /**
     * Obtain the context object for the given key.
     *
     * @param key The key of the required context object
     *
     * @return The value of the context object associated with the given key
     *
     * @throws NullPointerException
     *              If the supplied key is <code>null</code>
     */
    public Object getContext(@SuppressWarnings("rawtypes") Class key) {
        Objects.requireNonNull(key);
        if (this.map == null) {
            return null;
        }
        return this.map.get(key);
    }

    public abstract ELResolver getELResolver();

    /**
     * Obtain the ImportHandler for this ELContext, creating one if necessary.
     * This method is not thread-safe.
     *
     * @return the ImportHandler for this ELContext.
     *
     * @since EL 3.0
     */
    public ImportHandler getImportHandler() {
        if (importHandler == null) {
            importHandler = new ImportHandler();
        }
        return importHandler;
    }

    public abstract FunctionMapper getFunctionMapper();

    public Locale getLocale() {
        return this.locale;
    }

    public void setLocale(Locale locale) {
        this.locale = locale;
    }

    public abstract VariableMapper getVariableMapper();

    /**
     * Register an EvaluationListener with this ELContext.
     *
     * @param listener The EvaluationListener to register
     *
     * @since EL 3.0
     */
    public void addEvaluationListener(EvaluationListener listener) {
        listeners.add(listener);
    }

    /**
     * Obtain the list of registered EvaluationListeners.
     *
     * @return A list of the EvaluationListener registered with this ELContext
     *
     * @since EL 3.0
     */
    public List<EvaluationListener> getEvaluationListeners() {
        return listeners;
    }

    /**
     * Notify interested listeners that an expression will be evaluated.
     *
     * @param expression The expression that will be evaluated
     *
     * @since EL 3.0
     */
    public void notifyBeforeEvaluation(String expression) {
        for (EvaluationListener listener : listeners) {
            try {
                listener.beforeEvaluation(this, expression);
            } catch (Throwable t) {
                Util.handleThrowable(t);
                // Ignore - no option to log
            }
        }
    }

    /**
     * Notify interested listeners that an expression has been evaluated.
     *
     * @param expression The expression that was evaluated
     *
     * @since EL 3.0
     */
    public void notifyAfterEvaluation(String expression) {
        for (EvaluationListener listener : listeners) {
            try {
                listener.afterEvaluation(this, expression);
            } catch (Throwable t) {
                Util.handleThrowable(t);
                // Ignore - no option to log
            }
        }
    }

    /**
     * Notify interested listeners that a property has been resolved.
     *
     * @param base     The object on which the property was resolved
     * @param property The property that was resolved
     *
     * @since EL 3.0
     */
    public void notifyPropertyResolved(Object base, Object property) {
        for (EvaluationListener listener : listeners) {
            try {
                listener.propertyResolved(this, base, property);
            } catch (Throwable t) {
                Util.handleThrowable(t);
                // Ignore - no option to log
            }
        }
    }

    /**
     * Determine if the specified name is recognised as the name of a lambda
     * argument.
     *
     * @param name The name of the lambda argument
     *
     * @return <code>true</code> if the name is recognised as the name of a
     *         lambda argument, otherwise <code>false</code>
     *
     * @since EL 3.0
     */
    public boolean isLambdaArgument(String name) {
        for (Map<String,Object> arguments : lambdaArguments) {
            if (arguments.containsKey(name)) {
                return true;
            }
        }
        return false;
    }

    /**
     * Obtain the value of the lambda argument with the given name.
     *
     * @param name The name of the lambda argument
     *
     * @return The value of the specified argument
     *
     * @since EL 3.0
     */
    public Object getLambdaArgument(String name) {
        for (Map<String,Object> arguments : lambdaArguments) {
            Object result = arguments.get(name);
            if (result != null) {
                return result;
            }
        }
        return null;
    }

    /**
     * Called when starting to evaluate a lambda expression so that the
     * arguments are available to the EL context during evaluation.
     *
     * @param arguments The arguments in scope for the current lambda
     *                  expression.
     * @since EL 3.0
     */
    public void enterLambdaScope(Map<String,Object> arguments) {
        lambdaArguments.push(arguments);
    }

    /**
     * Called after evaluating a lambda expression to signal that the arguments
     * are no longer required.
     *
     * @since EL 3.0
     */
    public void exitLambdaScope() {
        lambdaArguments.pop();
    }

    /**
     * Coerce the supplied object to the requested type.
     *
     * @param obj  The object to be coerced
     * @param type The type to which the object should be coerced
     *
     * @return An instance of the requested type.
     *
     * @throws ELException
     *              If the conversion fails
     *
     * @since EL 3.0
     */
    public Object convertToType(Object obj, Class<?> type) {

        boolean originalResolved = isPropertyResolved();
        setPropertyResolved(false);
        try {
            ELResolver resolver = getELResolver();
            if (resolver != null) {
                Object result = resolver.convertToType(this, obj, type);
                if (isPropertyResolved()) {
                    return result;
                }
            }
        } finally {
            setPropertyResolved(originalResolved);
        }

        return ELManager.getExpressionFactory().coerceToType(obj, type);
    }
}