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Diffstat (limited to 'qpid/java/broker/src/main/java/org/apache/qpid/server/filter/ComparisonExpression.java')
| -rw-r--r-- | qpid/java/broker/src/main/java/org/apache/qpid/server/filter/ComparisonExpression.java | 599 |
1 files changed, 599 insertions, 0 deletions
diff --git a/qpid/java/broker/src/main/java/org/apache/qpid/server/filter/ComparisonExpression.java b/qpid/java/broker/src/main/java/org/apache/qpid/server/filter/ComparisonExpression.java new file mode 100644 index 0000000000..aad9d41174 --- /dev/null +++ b/qpid/java/broker/src/main/java/org/apache/qpid/server/filter/ComparisonExpression.java @@ -0,0 +1,599 @@ +/* + * + * 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 org.apache.qpid.server.filter; +// +// Based on like named file from r450141 of the Apache ActiveMQ project <http://www.activemq.org/site/home.html> +// + +import java.util.HashSet; +import java.util.List; +import java.util.regex.Pattern; + +import org.apache.qpid.server.queue.Filterable; + +/** + * A filter performing a comparison of two objects + */ +public abstract class ComparisonExpression extends BinaryExpression implements BooleanExpression +{ + + public static BooleanExpression createBetween(Expression value, Expression left, Expression right) + { + return LogicExpression.createAND(createGreaterThanEqual(value, left), createLessThanEqual(value, right)); + } + + public static BooleanExpression createNotBetween(Expression value, Expression left, Expression right) + { + return LogicExpression.createOR(createLessThan(value, left), createGreaterThan(value, right)); + } + + private static final HashSet<Character> REGEXP_CONTROL_CHARS = new HashSet<Character>(); + + static + { + REGEXP_CONTROL_CHARS.add('.'); + REGEXP_CONTROL_CHARS.add('\\'); + REGEXP_CONTROL_CHARS.add('['); + REGEXP_CONTROL_CHARS.add(']'); + REGEXP_CONTROL_CHARS.add('^'); + REGEXP_CONTROL_CHARS.add('$'); + REGEXP_CONTROL_CHARS.add('?'); + REGEXP_CONTROL_CHARS.add('*'); + REGEXP_CONTROL_CHARS.add('+'); + REGEXP_CONTROL_CHARS.add('{'); + REGEXP_CONTROL_CHARS.add('}'); + REGEXP_CONTROL_CHARS.add('|'); + REGEXP_CONTROL_CHARS.add('('); + REGEXP_CONTROL_CHARS.add(')'); + REGEXP_CONTROL_CHARS.add(':'); + REGEXP_CONTROL_CHARS.add('&'); + REGEXP_CONTROL_CHARS.add('<'); + REGEXP_CONTROL_CHARS.add('>'); + REGEXP_CONTROL_CHARS.add('='); + REGEXP_CONTROL_CHARS.add('!'); + } + + static class LikeExpression extends UnaryExpression implements BooleanExpression + { + + Pattern likePattern; + + /** + * @param right + */ + public LikeExpression(Expression right, String like, int escape) + { + super(right); + + StringBuffer regexp = new StringBuffer(like.length() * 2); + regexp.append("\\A"); // The beginning of the input + for (int i = 0; i < like.length(); i++) + { + char c = like.charAt(i); + if (escape == (0xFFFF & c)) + { + i++; + if (i >= like.length()) + { + // nothing left to escape... + break; + } + + char t = like.charAt(i); + regexp.append("\\x"); + regexp.append(Integer.toHexString(0xFFFF & t)); + } + else if (c == '%') + { + regexp.append(".*?"); // Do a non-greedy match + } + else if (c == '_') + { + regexp.append("."); // match one + } + else if (REGEXP_CONTROL_CHARS.contains(c)) + { + regexp.append("\\x"); + regexp.append(Integer.toHexString(0xFFFF & c)); + } + else + { + regexp.append(c); + } + } + + regexp.append("\\z"); // The end of the input + + likePattern = Pattern.compile(regexp.toString(), Pattern.DOTALL); + } + + /** + * org.apache.activemq.filter.UnaryExpression#getExpressionSymbol() + */ + public String getExpressionSymbol() + { + return "LIKE"; + } + + /** + * org.apache.activemq.filter.Expression#evaluate(MessageEvaluationContext) + */ + public Object evaluate(Filterable message) + { + + Object rv = this.getRight().evaluate(message); + + if (rv == null) + { + return null; + } + + if (!(rv instanceof String)) + { + return + Boolean.FALSE; + // throw new RuntimeException("LIKE can only operate on String identifiers. LIKE attemped on: '" + rv.getClass()); + } + + return likePattern.matcher((String) rv).matches() ? Boolean.TRUE : Boolean.FALSE; + } + + public boolean matches(Filterable message) + { + Object object = evaluate(message); + + return (object != null) && (object == Boolean.TRUE); + } + } + + public static BooleanExpression createLike(Expression left, String right, String escape) + { + if ((escape != null) && (escape.length() != 1)) + { + throw new RuntimeException( + "The ESCAPE string litteral is invalid. It can only be one character. Litteral used: " + escape); + } + + int c = -1; + if (escape != null) + { + c = 0xFFFF & escape.charAt(0); + } + + return new LikeExpression(left, right, c); + } + + public static BooleanExpression createNotLike(Expression left, String right, String escape) + { + return UnaryExpression.createNOT(createLike(left, right, escape)); + } + + public static BooleanExpression createInFilter(Expression left, List elements) + { + + if (!(left instanceof PropertyExpression)) + { + throw new RuntimeException("Expected a property for In expression, got: " + left); + } + + return UnaryExpression.createInExpression((PropertyExpression) left, elements, false); + + } + + public static BooleanExpression createNotInFilter(Expression left, List elements) + { + + if (!(left instanceof PropertyExpression)) + { + throw new RuntimeException("Expected a property for In expression, got: " + left); + } + + return UnaryExpression.createInExpression((PropertyExpression) left, elements, true); + + } + + public static BooleanExpression createIsNull(Expression left) + { + return doCreateEqual(left, ConstantExpression.NULL); + } + + public static BooleanExpression createIsNotNull(Expression left) + { + return UnaryExpression.createNOT(doCreateEqual(left, ConstantExpression.NULL)); + } + + public static BooleanExpression createNotEqual(Expression left, Expression right) + { + return UnaryExpression.createNOT(createEqual(left, right)); + } + + public static BooleanExpression createEqual(Expression left, Expression right) + { + checkEqualOperand(left); + checkEqualOperand(right); + checkEqualOperandCompatability(left, right); + + return doCreateEqual(left, right); + } + + private static BooleanExpression doCreateEqual(Expression left, Expression right) + { + return new EqualExpression(left, right); + } + + public static BooleanExpression createGreaterThan(final Expression left, final Expression right) + { + checkLessThanOperand(left); + checkLessThanOperand(right); + + return new ComparisonExpression(left, right) + { + protected boolean asBoolean(int answer) + { + return answer > 0; + } + + public String getExpressionSymbol() + { + return ">"; + } + }; + } + + public static BooleanExpression createGreaterThanEqual(final Expression left, final Expression right) + { + checkLessThanOperand(left); + checkLessThanOperand(right); + + return new ComparisonExpression(left, right) + { + protected boolean asBoolean(int answer) + { + return answer >= 0; + } + + public String getExpressionSymbol() + { + return ">="; + } + }; + } + + public static BooleanExpression createLessThan(final Expression left, final Expression right) + { + checkLessThanOperand(left); + checkLessThanOperand(right); + + return new ComparisonExpression(left, right) + { + + protected boolean asBoolean(int answer) + { + return answer < 0; + } + + public String getExpressionSymbol() + { + return "<"; + } + + }; + } + + public static BooleanExpression createLessThanEqual(final Expression left, final Expression right) + { + checkLessThanOperand(left); + checkLessThanOperand(right); + + return new ComparisonExpression(left, right) + { + + protected boolean asBoolean(int answer) + { + return answer <= 0; + } + + public String getExpressionSymbol() + { + return "<="; + } + }; + } + + /** + * Only Numeric expressions can be used in >, >=, < or <= expressions.s + * + * @param expr + */ + public static void checkLessThanOperand(Expression expr) + { + if (expr instanceof ConstantExpression) + { + Object value = ((ConstantExpression) expr).getValue(); + if (value instanceof Number) + { + return; + } + + // Else it's boolean or a String.. + throw new RuntimeException("Value '" + expr + "' cannot be compared."); + } + + if (expr instanceof BooleanExpression) + { + throw new RuntimeException("Value '" + expr + "' cannot be compared."); + } + } + + /** + * Validates that the expression can be used in == or <> expression. + * Cannot not be NULL TRUE or FALSE litterals. + * + * @param expr + */ + public static void checkEqualOperand(Expression expr) + { + if (expr instanceof ConstantExpression) + { + Object value = ((ConstantExpression) expr).getValue(); + if (value == null) + { + throw new RuntimeException("'" + expr + "' cannot be compared."); + } + } + } + + /** + * + * @param left + * @param right + */ + private static void checkEqualOperandCompatability(Expression left, Expression right) + { + if ((left instanceof ConstantExpression) && (right instanceof ConstantExpression)) + { + if ((left instanceof BooleanExpression) && !(right instanceof BooleanExpression)) + { + throw new RuntimeException("'" + left + "' cannot be compared with '" + right + "'"); + } + } + } + + /** + * @param left + * @param right + */ + public ComparisonExpression(Expression left, Expression right) + { + super(left, right); + } + + public Object evaluate(Filterable message) + { + Comparable lv = (Comparable) left.evaluate(message); + if (lv == null) + { + return null; + } + + Comparable rv = (Comparable) right.evaluate(message); + if (rv == null) + { + return null; + } + + return compare(lv, rv); + } + + protected Boolean compare(Comparable lv, Comparable rv) + { + Class lc = lv.getClass(); + Class rc = rv.getClass(); + // If the the objects are not of the same type, + // try to convert up to allow the comparison. + if (lc != rc) + { + if (lc == Byte.class) + { + if (rc == Short.class) + { + lv = ((Number) lv).shortValue(); + } + else if (rc == Integer.class) + { + lv = ((Number) lv).intValue(); + } + else if (rc == Long.class) + { + lv = ((Number) lv).longValue(); + } + else if (rc == Float.class) + { + lv = ((Number) lv).floatValue(); + } + else if (rc == Double.class) + { + lv = ((Number) lv).doubleValue(); + } + else + { + return Boolean.FALSE; + } + } + else if (lc == Short.class) + { + if (rc == Integer.class) + { + lv = ((Number) lv).intValue(); + } + else if (rc == Long.class) + { + lv = ((Number) lv).longValue(); + } + else if (rc == Float.class) + { + lv = ((Number) lv).floatValue(); + } + else if (rc == Double.class) + { + lv = ((Number) lv).doubleValue(); + } + else + { + return Boolean.FALSE; + } + } + else if (lc == Integer.class) + { + if (rc == Long.class) + { + lv = ((Number) lv).longValue(); + } + else if (rc == Float.class) + { + lv = ((Number) lv).floatValue(); + } + else if (rc == Double.class) + { + lv = ((Number) lv).doubleValue(); + } + else + { + return Boolean.FALSE; + } + } + else if (lc == Long.class) + { + if (rc == Integer.class) + { + rv = ((Number) rv).longValue(); + } + else if (rc == Float.class) + { + lv = ((Number) lv).floatValue(); + } + else if (rc == Double.class) + { + lv = ((Number) lv).doubleValue(); + } + else + { + return Boolean.FALSE; + } + } + else if (lc == Float.class) + { + if (rc == Integer.class) + { + rv = ((Number) rv).floatValue(); + } + else if (rc == Long.class) + { + rv = ((Number) rv).floatValue(); + } + else if (rc == Double.class) + { + lv = ((Number) lv).doubleValue(); + } + else + { + return Boolean.FALSE; + } + } + else if (lc == Double.class) + { + if (rc == Integer.class) + { + rv = ((Number) rv).doubleValue(); + } + else if (rc == Long.class) + { + rv = ((Number) rv).doubleValue(); + } + else if (rc == Float.class) + { + rv = ((Number) rv).doubleValue(); + } + else + { + return Boolean.FALSE; + } + } + else + { + return Boolean.FALSE; + } + } + + return asBoolean(lv.compareTo(rv)) ? Boolean.TRUE : Boolean.FALSE; + } + + protected abstract boolean asBoolean(int answer); + + public boolean matches(Filterable message) + { + Object object = evaluate(message); + + return (object != null) && (object == Boolean.TRUE); + } + + private static class EqualExpression extends ComparisonExpression + { + public EqualExpression(final Expression left, final Expression right) + { + super(left, right); + } + + public Object evaluate(Filterable message) + { + Object lv = left.evaluate(message); + Object rv = right.evaluate(message); + + // Iff one of the values is null + if ((lv == null) ^ (rv == null)) + { + return Boolean.FALSE; + } + + if ((lv == rv) || lv.equals(rv)) + { + return Boolean.TRUE; + } + + if ((lv instanceof Comparable) && (rv instanceof Comparable)) + { + return compare((Comparable) lv, (Comparable) rv); + } + + return Boolean.FALSE; + } + + protected boolean asBoolean(int answer) + { + return answer == 0; + } + + public String getExpressionSymbol() + { + return "="; + } + } +} |