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.activemq.filter;
018
019 import java.util.HashSet;
020 import java.util.List;
021 import java.util.Set;
022 import java.util.regex.Pattern;
023
024 import javax.jms.JMSException;
025
026 /**
027 * A filter performing a comparison of two objects
028 *
029 *
030 */
031 public abstract class ComparisonExpression extends BinaryExpression implements BooleanExpression {
032
033 private static final Set<Character> REGEXP_CONTROL_CHARS = new HashSet<Character>();
034
035 /**
036 * @param left
037 * @param right
038 */
039 public ComparisonExpression(Expression left, Expression right) {
040 super(left, right);
041 }
042
043 public static BooleanExpression createBetween(Expression value, Expression left, Expression right) {
044 return LogicExpression.createAND(createGreaterThanEqual(value, left), createLessThanEqual(value, right));
045 }
046
047 public static BooleanExpression createNotBetween(Expression value, Expression left, Expression right) {
048 return LogicExpression.createOR(createLessThan(value, left), createGreaterThan(value, right));
049 }
050
051 static {
052 REGEXP_CONTROL_CHARS.add(Character.valueOf('.'));
053 REGEXP_CONTROL_CHARS.add(Character.valueOf('\\'));
054 REGEXP_CONTROL_CHARS.add(Character.valueOf('['));
055 REGEXP_CONTROL_CHARS.add(Character.valueOf(']'));
056 REGEXP_CONTROL_CHARS.add(Character.valueOf('^'));
057 REGEXP_CONTROL_CHARS.add(Character.valueOf('$'));
058 REGEXP_CONTROL_CHARS.add(Character.valueOf('?'));
059 REGEXP_CONTROL_CHARS.add(Character.valueOf('*'));
060 REGEXP_CONTROL_CHARS.add(Character.valueOf('+'));
061 REGEXP_CONTROL_CHARS.add(Character.valueOf('{'));
062 REGEXP_CONTROL_CHARS.add(Character.valueOf('}'));
063 REGEXP_CONTROL_CHARS.add(Character.valueOf('|'));
064 REGEXP_CONTROL_CHARS.add(Character.valueOf('('));
065 REGEXP_CONTROL_CHARS.add(Character.valueOf(')'));
066 REGEXP_CONTROL_CHARS.add(Character.valueOf(':'));
067 REGEXP_CONTROL_CHARS.add(Character.valueOf('&'));
068 REGEXP_CONTROL_CHARS.add(Character.valueOf('<'));
069 REGEXP_CONTROL_CHARS.add(Character.valueOf('>'));
070 REGEXP_CONTROL_CHARS.add(Character.valueOf('='));
071 REGEXP_CONTROL_CHARS.add(Character.valueOf('!'));
072 }
073
074 static class LikeExpression extends UnaryExpression implements BooleanExpression {
075
076 Pattern likePattern;
077
078 /**
079 * @param left
080 */
081 public LikeExpression(Expression right, String like, int escape) {
082 super(right);
083
084 StringBuffer regexp = new StringBuffer(like.length() * 2);
085 regexp.append("\\A"); // The beginning of the input
086 for (int i = 0; i < like.length(); i++) {
087 char c = like.charAt(i);
088 if (escape == (0xFFFF & c)) {
089 i++;
090 if (i >= like.length()) {
091 // nothing left to escape...
092 break;
093 }
094
095 char t = like.charAt(i);
096 regexp.append("\\x");
097 regexp.append(Integer.toHexString(0xFFFF & t));
098 } else if (c == '%') {
099 regexp.append(".*?"); // Do a non-greedy match
100 } else if (c == '_') {
101 regexp.append("."); // match one
102 } else if (REGEXP_CONTROL_CHARS.contains(new Character(c))) {
103 regexp.append("\\x");
104 regexp.append(Integer.toHexString(0xFFFF & c));
105 } else {
106 regexp.append(c);
107 }
108 }
109 regexp.append("\\z"); // The end of the input
110
111 likePattern = Pattern.compile(regexp.toString(), Pattern.DOTALL);
112 }
113
114 /**
115 * @see org.apache.activemq.filter.UnaryExpression#getExpressionSymbol()
116 */
117 public String getExpressionSymbol() {
118 return "LIKE";
119 }
120
121 /**
122 * @see org.apache.activemq.filter.Expression#evaluate(MessageEvaluationContext)
123 */
124 public Object evaluate(MessageEvaluationContext message) throws JMSException {
125
126 Object rv = this.getRight().evaluate(message);
127
128 if (rv == null) {
129 return null;
130 }
131
132 if (!(rv instanceof String)) {
133 return Boolean.FALSE;
134 // throw new RuntimeException("LIKE can only operate on String
135 // identifiers. LIKE attemped on: '" + rv.getClass());
136 }
137
138 return likePattern.matcher((String)rv).matches() ? Boolean.TRUE : Boolean.FALSE;
139 }
140
141 public boolean matches(MessageEvaluationContext message) throws JMSException {
142 Object object = evaluate(message);
143 return object != null && object == Boolean.TRUE;
144 }
145 }
146
147 public static BooleanExpression createLike(Expression left, String right, String escape) {
148 if (escape != null && escape.length() != 1) {
149 throw new RuntimeException("The ESCAPE string litteral is invalid. It can only be one character. Litteral used: " + escape);
150 }
151 int c = -1;
152 if (escape != null) {
153 c = 0xFFFF & escape.charAt(0);
154 }
155
156 return new LikeExpression(left, right, c);
157 }
158
159 public static BooleanExpression createNotLike(Expression left, String right, String escape) {
160 return UnaryExpression.createNOT(createLike(left, right, escape));
161 }
162
163 @SuppressWarnings({ "rawtypes", "unchecked" })
164 public static BooleanExpression createInFilter(Expression left, List elements) {
165
166 if (!(left instanceof PropertyExpression)) {
167 throw new RuntimeException("Expected a property for In expression, got: " + left);
168 }
169 return UnaryExpression.createInExpression((PropertyExpression)left, elements, false);
170
171 }
172
173 @SuppressWarnings({ "rawtypes", "unchecked" })
174 public static BooleanExpression createNotInFilter(Expression left, List elements) {
175
176 if (!(left instanceof PropertyExpression)) {
177 throw new RuntimeException("Expected a property for In expression, got: " + left);
178 }
179 return UnaryExpression.createInExpression((PropertyExpression)left, elements, true);
180
181 }
182
183 public static BooleanExpression createIsNull(Expression left) {
184 return doCreateEqual(left, ConstantExpression.NULL);
185 }
186
187 public static BooleanExpression createIsNotNull(Expression left) {
188 return UnaryExpression.createNOT(doCreateEqual(left, ConstantExpression.NULL));
189 }
190
191 public static BooleanExpression createNotEqual(Expression left, Expression right) {
192 return UnaryExpression.createNOT(createEqual(left, right));
193 }
194
195 public static BooleanExpression createEqual(Expression left, Expression right) {
196 checkEqualOperand(left);
197 checkEqualOperand(right);
198 checkEqualOperandCompatability(left, right);
199 return doCreateEqual(left, right);
200 }
201
202 @SuppressWarnings({ "rawtypes" })
203 private static BooleanExpression doCreateEqual(Expression left, Expression right) {
204 return new ComparisonExpression(left, right) {
205
206 public Object evaluate(MessageEvaluationContext message) throws JMSException {
207 Object lv = left.evaluate(message);
208 Object rv = right.evaluate(message);
209
210 // If one of the values is null
211 if (lv == null ^ rv == null) {
212 return Boolean.FALSE;
213 }
214 if (lv == rv || lv.equals(rv)) {
215 return Boolean.TRUE;
216 }
217 if (lv instanceof Comparable && rv instanceof Comparable) {
218 return compare((Comparable)lv, (Comparable)rv);
219 }
220 return Boolean.FALSE;
221 }
222
223 protected boolean asBoolean(int answer) {
224 return answer == 0;
225 }
226
227 public String getExpressionSymbol() {
228 return "=";
229 }
230 };
231 }
232
233 public static BooleanExpression createGreaterThan(final Expression left, final Expression right) {
234 checkLessThanOperand(left);
235 checkLessThanOperand(right);
236 return new ComparisonExpression(left, right) {
237 protected boolean asBoolean(int answer) {
238 return answer > 0;
239 }
240
241 public String getExpressionSymbol() {
242 return ">";
243 }
244 };
245 }
246
247 public static BooleanExpression createGreaterThanEqual(final Expression left, final Expression right) {
248 checkLessThanOperand(left);
249 checkLessThanOperand(right);
250 return new ComparisonExpression(left, right) {
251 protected boolean asBoolean(int answer) {
252 return answer >= 0;
253 }
254
255 public String getExpressionSymbol() {
256 return ">=";
257 }
258 };
259 }
260
261 public static BooleanExpression createLessThan(final Expression left, final Expression right) {
262 checkLessThanOperand(left);
263 checkLessThanOperand(right);
264 return new ComparisonExpression(left, right) {
265
266 protected boolean asBoolean(int answer) {
267 return answer < 0;
268 }
269
270 public String getExpressionSymbol() {
271 return "<";
272 }
273
274 };
275 }
276
277 public static BooleanExpression createLessThanEqual(final Expression left, final Expression right) {
278 checkLessThanOperand(left);
279 checkLessThanOperand(right);
280 return new ComparisonExpression(left, right) {
281
282 protected boolean asBoolean(int answer) {
283 return answer <= 0;
284 }
285
286 public String getExpressionSymbol() {
287 return "<=";
288 }
289 };
290 }
291
292 /**
293 * Only Numeric expressions can be used in >, >=, < or <= expressions.s
294 *
295 * @param expr
296 */
297 public static void checkLessThanOperand(Expression expr) {
298 if (expr instanceof ConstantExpression) {
299 Object value = ((ConstantExpression)expr).getValue();
300 if (value instanceof Number) {
301 return;
302 }
303
304 // Else it's boolean or a String..
305 throw new RuntimeException("Value '" + expr + "' cannot be compared.");
306 }
307 if (expr instanceof BooleanExpression) {
308 throw new RuntimeException("Value '" + expr + "' cannot be compared.");
309 }
310 }
311
312 /**
313 * Validates that the expression can be used in == or <> expression. Cannot
314 * not be NULL TRUE or FALSE litterals.
315 *
316 * @param expr
317 */
318 public static void checkEqualOperand(Expression expr) {
319 if (expr instanceof ConstantExpression) {
320 Object value = ((ConstantExpression)expr).getValue();
321 if (value == null) {
322 throw new RuntimeException("'" + expr + "' cannot be compared.");
323 }
324 }
325 }
326
327 /**
328 * @param left
329 * @param right
330 */
331 private static void checkEqualOperandCompatability(Expression left, Expression right) {
332 if (left instanceof ConstantExpression && right instanceof ConstantExpression) {
333 if (left instanceof BooleanExpression && !(right instanceof BooleanExpression)) {
334 throw new RuntimeException("'" + left + "' cannot be compared with '" + right + "'");
335 }
336 }
337 }
338
339 @SuppressWarnings({ "rawtypes", "unchecked" })
340 public Object evaluate(MessageEvaluationContext message) throws JMSException {
341 Comparable<Comparable> lv = (Comparable)left.evaluate(message);
342 if (lv == null) {
343 return null;
344 }
345 Comparable rv = (Comparable)right.evaluate(message);
346 if (rv == null) {
347 return null;
348 }
349 return compare(lv, rv);
350 }
351
352 @SuppressWarnings({ "rawtypes", "unchecked" })
353 protected Boolean compare(Comparable lv, Comparable rv) {
354 Class<? extends Comparable> lc = lv.getClass();
355 Class<? extends Comparable> rc = rv.getClass();
356 // If the the objects are not of the same type,
357 // try to convert up to allow the comparison.
358 if (lc != rc) {
359 try {
360 if (lc == Boolean.class) {
361 if (rc == String.class) {
362 lv = Boolean.valueOf((String)lv).booleanValue();
363 } else {
364 return Boolean.FALSE;
365 }
366 } else if (lc == Byte.class) {
367 if (rc == Short.class) {
368 lv = Short.valueOf(((Number)lv).shortValue());
369 } else if (rc == Integer.class) {
370 lv = Integer.valueOf(((Number)lv).intValue());
371 } else if (rc == Long.class) {
372 lv = Long.valueOf(((Number)lv).longValue());
373 } else if (rc == Float.class) {
374 lv = new Float(((Number)lv).floatValue());
375 } else if (rc == Double.class) {
376 lv = new Double(((Number)lv).doubleValue());
377 } else if (rc == String.class) {
378 rv = Byte.valueOf((String)rv);
379 } else {
380 return Boolean.FALSE;
381 }
382 } else if (lc == Short.class) {
383 if (rc == Integer.class) {
384 lv = Integer.valueOf(((Number)lv).intValue());
385 } else if (rc == Long.class) {
386 lv = Long.valueOf(((Number)lv).longValue());
387 } else if (rc == Float.class) {
388 lv = new Float(((Number)lv).floatValue());
389 } else if (rc == Double.class) {
390 lv = new Double(((Number)lv).doubleValue());
391 } else if (rc == String.class) {
392 rv = Short.valueOf((String)rv);
393 } else {
394 return Boolean.FALSE;
395 }
396 } else if (lc == Integer.class) {
397 if (rc == Long.class) {
398 lv = Long.valueOf(((Number)lv).longValue());
399 } else if (rc == Float.class) {
400 lv = new Float(((Number)lv).floatValue());
401 } else if (rc == Double.class) {
402 lv = new Double(((Number)lv).doubleValue());
403 } else if (rc == String.class) {
404 rv = Integer.valueOf((String)rv);
405 } else {
406 return Boolean.FALSE;
407 }
408 } else if (lc == Long.class) {
409 if (rc == Integer.class) {
410 rv = Long.valueOf(((Number)rv).longValue());
411 } else if (rc == Float.class) {
412 lv = new Float(((Number)lv).floatValue());
413 } else if (rc == Double.class) {
414 lv = new Double(((Number)lv).doubleValue());
415 } else if (rc == String.class) {
416 rv = Long.valueOf((String)rv);
417 } else {
418 return Boolean.FALSE;
419 }
420 } else if (lc == Float.class) {
421 if (rc == Integer.class) {
422 rv = new Float(((Number)rv).floatValue());
423 } else if (rc == Long.class) {
424 rv = new Float(((Number)rv).floatValue());
425 } else if (rc == Double.class) {
426 lv = new Double(((Number)lv).doubleValue());
427 } else if (rc == String.class) {
428 rv = Float.valueOf((String)rv);
429 } else {
430 return Boolean.FALSE;
431 }
432 } else if (lc == Double.class) {
433 if (rc == Integer.class) {
434 rv = new Double(((Number)rv).doubleValue());
435 } else if (rc == Long.class) {
436 rv = new Double(((Number)rv).doubleValue());
437 } else if (rc == Float.class) {
438 rv = new Float(((Number)rv).doubleValue());
439 } else if (rc == String.class) {
440 rv = Double.valueOf((String)rv);
441 } else {
442 return Boolean.FALSE;
443 }
444 } else if (lc == String.class) {
445 if (rc == Boolean.class) {
446 lv = Boolean.valueOf((String)lv);
447 } else if (rc == Byte.class) {
448 lv = Byte.valueOf((String)lv);
449 } else if (rc == Short.class) {
450 lv = Short.valueOf((String)lv);
451 } else if (rc == Integer.class) {
452 lv = Integer.valueOf((String)lv);
453 } else if (rc == Long.class) {
454 lv = Long.valueOf((String)lv);
455 } else if (rc == Float.class) {
456 lv = Float.valueOf((String)lv);
457 } else if (rc == Double.class) {
458 lv = Double.valueOf((String)lv);
459 } else {
460 return Boolean.FALSE;
461 }
462 } else {
463 return Boolean.FALSE;
464 }
465 } catch(NumberFormatException e) {
466 return Boolean.FALSE;
467 }
468 }
469 return asBoolean(lv.compareTo(rv)) ? Boolean.TRUE : Boolean.FALSE;
470 }
471
472 protected abstract boolean asBoolean(int answer);
473
474 public boolean matches(MessageEvaluationContext message) throws JMSException {
475 Object object = evaluate(message);
476 return object != null && object == Boolean.TRUE;
477 }
478
479 }