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 public static BooleanExpression createInFilter(Expression left, List elements) {
164
165 if (!(left instanceof PropertyExpression)) {
166 throw new RuntimeException("Expected a property for In expression, got: " + left);
167 }
168 return UnaryExpression.createInExpression((PropertyExpression)left, elements, false);
169
170 }
171
172 public static BooleanExpression createNotInFilter(Expression left, List elements) {
173
174 if (!(left instanceof PropertyExpression)) {
175 throw new RuntimeException("Expected a property for In expression, got: " + left);
176 }
177 return UnaryExpression.createInExpression((PropertyExpression)left, elements, true);
178
179 }
180
181 public static BooleanExpression createIsNull(Expression left) {
182 return doCreateEqual(left, ConstantExpression.NULL);
183 }
184
185 public static BooleanExpression createIsNotNull(Expression left) {
186 return UnaryExpression.createNOT(doCreateEqual(left, ConstantExpression.NULL));
187 }
188
189 public static BooleanExpression createNotEqual(Expression left, Expression right) {
190 return UnaryExpression.createNOT(createEqual(left, right));
191 }
192
193 public static BooleanExpression createEqual(Expression left, Expression right) {
194 checkEqualOperand(left);
195 checkEqualOperand(right);
196 checkEqualOperandCompatability(left, right);
197 return doCreateEqual(left, right);
198 }
199
200 private static BooleanExpression doCreateEqual(Expression left, Expression right) {
201 return new ComparisonExpression(left, right) {
202
203 public Object evaluate(MessageEvaluationContext message) throws JMSException {
204 Object lv = left.evaluate(message);
205 Object rv = right.evaluate(message);
206
207 // Iff one of the values is null
208 if (lv == null ^ rv == null) {
209 return Boolean.FALSE;
210 }
211 if (lv == rv || lv.equals(rv)) {
212 return Boolean.TRUE;
213 }
214 if (lv instanceof Comparable && rv instanceof Comparable) {
215 return compare((Comparable)lv, (Comparable)rv);
216 }
217 return Boolean.FALSE;
218 }
219
220 protected boolean asBoolean(int answer) {
221 return answer == 0;
222 }
223
224 public String getExpressionSymbol() {
225 return "=";
226 }
227 };
228 }
229
230 public static BooleanExpression createGreaterThan(final Expression left, final Expression right) {
231 checkLessThanOperand(left);
232 checkLessThanOperand(right);
233 return new ComparisonExpression(left, right) {
234 protected boolean asBoolean(int answer) {
235 return answer > 0;
236 }
237
238 public String getExpressionSymbol() {
239 return ">";
240 }
241 };
242 }
243
244 public static BooleanExpression createGreaterThanEqual(final Expression left, final Expression right) {
245 checkLessThanOperand(left);
246 checkLessThanOperand(right);
247 return new ComparisonExpression(left, right) {
248 protected boolean asBoolean(int answer) {
249 return answer >= 0;
250 }
251
252 public String getExpressionSymbol() {
253 return ">=";
254 }
255 };
256 }
257
258 public static BooleanExpression createLessThan(final Expression left, final Expression right) {
259 checkLessThanOperand(left);
260 checkLessThanOperand(right);
261 return new ComparisonExpression(left, right) {
262
263 protected boolean asBoolean(int answer) {
264 return answer < 0;
265 }
266
267 public String getExpressionSymbol() {
268 return "<";
269 }
270
271 };
272 }
273
274 public static BooleanExpression createLessThanEqual(final Expression left, final Expression right) {
275 checkLessThanOperand(left);
276 checkLessThanOperand(right);
277 return new ComparisonExpression(left, right) {
278
279 protected boolean asBoolean(int answer) {
280 return answer <= 0;
281 }
282
283 public String getExpressionSymbol() {
284 return "<=";
285 }
286 };
287 }
288
289 /**
290 * Only Numeric expressions can be used in >, >=, < or <= expressions.s
291 *
292 * @param expr
293 */
294 public static void checkLessThanOperand(Expression expr) {
295 if (expr instanceof ConstantExpression) {
296 Object value = ((ConstantExpression)expr).getValue();
297 if (value instanceof Number) {
298 return;
299 }
300
301 // Else it's boolean or a String..
302 throw new RuntimeException("Value '" + expr + "' cannot be compared.");
303 }
304 if (expr instanceof BooleanExpression) {
305 throw new RuntimeException("Value '" + expr + "' cannot be compared.");
306 }
307 }
308
309 /**
310 * Validates that the expression can be used in == or <> expression. Cannot
311 * not be NULL TRUE or FALSE litterals.
312 *
313 * @param expr
314 */
315 public static void checkEqualOperand(Expression expr) {
316 if (expr instanceof ConstantExpression) {
317 Object value = ((ConstantExpression)expr).getValue();
318 if (value == null) {
319 throw new RuntimeException("'" + expr + "' cannot be compared.");
320 }
321 }
322 }
323
324 /**
325 * @param left
326 * @param right
327 */
328 private static void checkEqualOperandCompatability(Expression left, Expression right) {
329 if (left instanceof ConstantExpression && right instanceof ConstantExpression) {
330 if (left instanceof BooleanExpression && !(right instanceof BooleanExpression)) {
331 throw new RuntimeException("'" + left + "' cannot be compared with '" + right + "'");
332 }
333 }
334 }
335
336 public Object evaluate(MessageEvaluationContext message) throws JMSException {
337 Comparable<Comparable> lv = (Comparable)left.evaluate(message);
338 if (lv == null) {
339 return null;
340 }
341 Comparable rv = (Comparable)right.evaluate(message);
342 if (rv == null) {
343 return null;
344 }
345 return compare(lv, rv);
346 }
347
348 protected Boolean compare(Comparable lv, Comparable rv) {
349 Class<? extends Comparable> lc = lv.getClass();
350 Class<? extends Comparable> rc = rv.getClass();
351 // If the the objects are not of the same type,
352 // try to convert up to allow the comparison.
353 if (lc != rc) {
354 if (lc == Byte.class) {
355 if (rc == Short.class) {
356 lv = Short.valueOf(((Number)lv).shortValue());
357 } else if (rc == Integer.class) {
358 lv = Integer.valueOf(((Number)lv).intValue());
359 } else if (rc == Long.class) {
360 lv = Long.valueOf(((Number)lv).longValue());
361 } else if (rc == Float.class) {
362 lv = new Float(((Number)lv).floatValue());
363 } else if (rc == Double.class) {
364 lv = new Double(((Number)lv).doubleValue());
365 } else {
366 return Boolean.FALSE;
367 }
368 } else if (lc == Short.class) {
369 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 {
378 return Boolean.FALSE;
379 }
380 } else if (lc == Integer.class) {
381 if (rc == Long.class) {
382 lv = Long.valueOf(((Number)lv).longValue());
383 } else if (rc == Float.class) {
384 lv = new Float(((Number)lv).floatValue());
385 } else if (rc == Double.class) {
386 lv = new Double(((Number)lv).doubleValue());
387 } else {
388 return Boolean.FALSE;
389 }
390 } else if (lc == Long.class) {
391 if (rc == Integer.class) {
392 rv = Long.valueOf(((Number)rv).longValue());
393 } else if (rc == Float.class) {
394 lv = new Float(((Number)lv).floatValue());
395 } else if (rc == Double.class) {
396 lv = new Double(((Number)lv).doubleValue());
397 } else {
398 return Boolean.FALSE;
399 }
400 } else if (lc == Float.class) {
401 if (rc == Integer.class) {
402 rv = new Float(((Number)rv).floatValue());
403 } else if (rc == Long.class) {
404 rv = new Float(((Number)rv).floatValue());
405 } else if (rc == Double.class) {
406 lv = new Double(((Number)lv).doubleValue());
407 } else {
408 return Boolean.FALSE;
409 }
410 } else if (lc == Double.class) {
411 if (rc == Integer.class) {
412 rv = new Double(((Number)rv).doubleValue());
413 } else if (rc == Long.class) {
414 rv = new Double(((Number)rv).doubleValue());
415 } else if (rc == Float.class) {
416 rv = new Float(((Number)rv).doubleValue());
417 } else {
418 return Boolean.FALSE;
419 }
420 } else {
421 return Boolean.FALSE;
422 }
423 }
424 return asBoolean(lv.compareTo(rv)) ? Boolean.TRUE : Boolean.FALSE;
425 }
426
427 protected abstract boolean asBoolean(int answer);
428
429 public boolean matches(MessageEvaluationContext message) throws JMSException {
430 Object object = evaluate(message);
431 return object != null && object == Boolean.TRUE;
432 }
433
434 }