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Diffstat (limited to 'qpid/java/common/src/main/java/org/apache/qpid/filter/UnaryExpression.java')
| -rw-r--r-- | qpid/java/common/src/main/java/org/apache/qpid/filter/UnaryExpression.java | 340 |
1 files changed, 340 insertions, 0 deletions
diff --git a/qpid/java/common/src/main/java/org/apache/qpid/filter/UnaryExpression.java b/qpid/java/common/src/main/java/org/apache/qpid/filter/UnaryExpression.java new file mode 100644 index 0000000000..b80b89840c --- /dev/null +++ b/qpid/java/common/src/main/java/org/apache/qpid/filter/UnaryExpression.java @@ -0,0 +1,340 @@ +/* + * + * 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.filter; +// +// Based on like named file from r450141 of the Apache ActiveMQ project <http://www.activemq.org/site/home.html> +// + +import java.math.BigDecimal; +import java.util.Collection; +import java.util.HashSet; +import java.util.List; + +/** + * An expression which performs an operation on two expression values + */ +public abstract class UnaryExpression implements Expression +{ + + private static final BigDecimal BD_LONG_MIN_VALUE = BigDecimal.valueOf(Long.MIN_VALUE); + private Expression right; + + public static Expression createNegate(Expression left) + { + return new NegativeExpression(left); + } + + public static BooleanExpression createInExpression(PropertyExpression right, List elements, final boolean not) + { + + // Use a HashSet if there are many elements. + Collection t; + if (elements.size() == 0) + { + t = null; + } + else if (elements.size() < 5) + { + t = elements; + } + else + { + t = new HashSet(elements); + } + + final Collection inList = t; + + return new InExpression(right, inList, not); + } + + abstract static class BooleanUnaryExpression extends UnaryExpression implements BooleanExpression + { + public BooleanUnaryExpression(Expression left) + { + super(left); + } + + public boolean matches(FilterableMessage message) + { + Object object = evaluate(message); + + return (object != null) && (object == Boolean.TRUE); + } + } + + public static BooleanExpression createNOT(BooleanExpression left) + { + return new NotExpression(left); + } + + public static BooleanExpression createBooleanCast(Expression left) + { + return new BooleanCastExpression(left); + } + + private static Number negate(Number left) + { + Class clazz = left.getClass(); + if (clazz == Integer.class) + { + return -left.intValue(); + } + else if (clazz == Long.class) + { + return -left.longValue(); + } + else if (clazz == Float.class) + { + return -left.floatValue(); + } + else if (clazz == Double.class) + { + return -left.doubleValue(); + } + else if (clazz == BigDecimal.class) + { + // We ussually get a big deciamal when we have Long.MIN_VALUE constant in the + // Selector. Long.MIN_VALUE is too big to store in a Long as a positive so we store it + // as a Big decimal. But it gets Negated right away.. to here we try to covert it back + // to a Long. + BigDecimal bd = (BigDecimal) left; + bd = bd.negate(); + + if (BD_LONG_MIN_VALUE.compareTo(bd) == 0) + { + return Long.MIN_VALUE; + } + + return bd; + } + else + { + throw new SelectorParsingException("Don't know how to negate: " + left); + } + } + + public UnaryExpression(Expression left) + { + this.right = left; + } + + public Expression getRight() + { + return right; + } + + /** + * @see java.lang.Object#toString() + */ + public String toString() + { + return "(" + getExpressionSymbol() + " " + right.toString() + ")"; + } + + /** + * TODO: more efficient hashCode() + * + * @see java.lang.Object#hashCode() + */ + public int hashCode() + { + return toString().hashCode(); + } + + /** + * TODO: more efficient hashCode() + * + * @see java.lang.Object#equals(java.lang.Object) + */ + public boolean equals(Object o) + { + return ((o != null) && this.getClass().equals(o.getClass())) && toString().equals(o.toString()); + } + + /** + * Returns the symbol that represents this binary expression. For example, addition is + * represented by "+" + * + * @return symbol + */ + public abstract String getExpressionSymbol(); + + private static class NegativeExpression extends UnaryExpression + { + public NegativeExpression(final Expression left) + { + super(left); + } + + public Object evaluate(FilterableMessage message) + { + Object rvalue = getRight().evaluate(message); + if (rvalue == null) + { + return null; + } + + if (rvalue instanceof Number) + { + return negate((Number) rvalue); + } + + return null; + } + + public String getExpressionSymbol() + { + return "-"; + } + } + + private static class InExpression extends BooleanUnaryExpression + { + private final Collection _inList; + private final boolean _not; + + public InExpression(final PropertyExpression right, final Collection inList, final boolean not) + { + super(right); + _inList = inList; + _not = not; + } + + public Object evaluate(FilterableMessage message) + { + + Object rvalue = getRight().evaluate(message); + if (rvalue == null) + { + return null; + } + + if (rvalue.getClass() != String.class) + { + return null; + } + + if (((_inList != null) && _inList.contains(rvalue)) ^ _not) + { + return Boolean.TRUE; + } + else + { + return Boolean.FALSE; + } + + } + + public String toString() + { + StringBuilder answer = new StringBuilder(String.valueOf(getRight())); + answer.append(" "); + answer.append(getExpressionSymbol()); + answer.append(" ( "); + + int count = 0; + for (Object o : _inList) + { + if (count != 0) + { + answer.append(", "); + } + + answer.append(o); + count++; + } + + answer.append(" )"); + + return answer.toString(); + } + + public String getExpressionSymbol() + { + if (_not) + { + return "NOT IN"; + } + else + { + return "IN"; + } + } + } + + private static class NotExpression extends BooleanUnaryExpression + { + public NotExpression(final BooleanExpression left) + { + super(left); + } + + public Object evaluate(FilterableMessage message) + { + Boolean lvalue = (Boolean) getRight().evaluate(message); + if (lvalue == null) + { + return null; + } + + return lvalue ? Boolean.FALSE : Boolean.TRUE; + } + + public String getExpressionSymbol() + { + return "NOT"; + } + } + + private static class BooleanCastExpression extends BooleanUnaryExpression + { + public BooleanCastExpression(final Expression left) + { + super(left); + } + + public Object evaluate(FilterableMessage message) + { + Object rvalue = getRight().evaluate(message); + if (rvalue == null) + { + return null; + } + + if (!rvalue.getClass().equals(Boolean.class)) + { + return Boolean.FALSE; + } + + return ((Boolean) rvalue) ? Boolean.TRUE : Boolean.FALSE; + } + + public String toString() + { + return getRight().toString(); + } + + public String getExpressionSymbol() + { + return ""; + } + } +} |