diff options
Diffstat (limited to 'qpid/java/client/src/main/java/org/apache/qpid/filter')
11 files changed, 2055 insertions, 0 deletions
diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/ArithmeticExpression.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/ArithmeticExpression.java new file mode 100644 index 0000000000..a86613f10c --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/ArithmeticExpression.java @@ -0,0 +1,268 @@ +/* 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; + +import org.apache.qpid.AMQInternalException; +import org.apache.qpid.client.message.AbstractJMSMessage; + + +/** + * An expression which performs an operation on two expression values + */ +public abstract class ArithmeticExpression extends BinaryExpression +{ + + protected static final int INTEGER = 1; + protected static final int LONG = 2; + protected static final int DOUBLE = 3; + + + public ArithmeticExpression(Expression left, Expression right) + { + super(left, right); + } + + public static Expression createPlus(Expression left, Expression right) + { + return new ArithmeticExpression(left, right) + { + protected Object evaluate(Object lvalue, Object rvalue) + { + if (lvalue instanceof String) + { + String text = (String) lvalue; + return text + rvalue; + } + else if (lvalue instanceof Number) + { + return plus((Number) lvalue, asNumber(rvalue)); + } + + throw new RuntimeException("Cannot call plus operation on: " + lvalue + " and: " + rvalue); + } + + public String getExpressionSymbol() + { + return "+"; + } + }; + } + + public static Expression createMinus(Expression left, Expression right) + { + return new ArithmeticExpression(left, right) + { + protected Object evaluate(Object lvalue, Object rvalue) + { + if (lvalue instanceof Number) + { + return minus((Number) lvalue, asNumber(rvalue)); + } + + throw new RuntimeException("Cannot call minus operation on: " + lvalue + " and: " + rvalue); + } + + public String getExpressionSymbol() + { + return "-"; + } + }; + } + + public static Expression createMultiply(Expression left, Expression right) + { + return new ArithmeticExpression(left, right) + { + + protected Object evaluate(Object lvalue, Object rvalue) + { + if (lvalue instanceof Number) + { + return multiply((Number) lvalue, asNumber(rvalue)); + } + + throw new RuntimeException("Cannot call multiply operation on: " + lvalue + " and: " + rvalue); + } + + public String getExpressionSymbol() + { + return "*"; + } + }; + } + + public static Expression createDivide(Expression left, Expression right) + { + return new ArithmeticExpression(left, right) + { + + protected Object evaluate(Object lvalue, Object rvalue) + { + if (lvalue instanceof Number) + { + return divide((Number) lvalue, asNumber(rvalue)); + } + + throw new RuntimeException("Cannot call divide operation on: " + lvalue + " and: " + rvalue); + } + + public String getExpressionSymbol() + { + return "/"; + } + }; + } + + public static Expression createMod(Expression left, Expression right) + { + return new ArithmeticExpression(left, right) + { + + protected Object evaluate(Object lvalue, Object rvalue) + { + if (lvalue instanceof Number) + { + return mod((Number) lvalue, asNumber(rvalue)); + } + + throw new RuntimeException("Cannot call mod operation on: " + lvalue + " and: " + rvalue); + } + + public String getExpressionSymbol() + { + return "%"; + } + }; + } + + protected Number plus(Number left, Number right) + { + switch (numberType(left, right)) + { + + case ArithmeticExpression.INTEGER: + return new Integer(left.intValue() + right.intValue()); + + case ArithmeticExpression.LONG: + return new Long(left.longValue() + right.longValue()); + + default: + return new Double(left.doubleValue() + right.doubleValue()); + } + } + + protected Number minus(Number left, Number right) + { + switch (numberType(left, right)) + { + + case ArithmeticExpression.INTEGER: + return new Integer(left.intValue() - right.intValue()); + + case ArithmeticExpression.LONG: + return new Long(left.longValue() - right.longValue()); + + default: + return new Double(left.doubleValue() - right.doubleValue()); + } + } + + protected Number multiply(Number left, Number right) + { + switch (numberType(left, right)) + { + + case ArithmeticExpression.INTEGER: + return new Integer(left.intValue() * right.intValue()); + + case ArithmeticExpression.LONG: + return new Long(left.longValue() * right.longValue()); + + default: + return new Double(left.doubleValue() * right.doubleValue()); + } + } + + protected Number divide(Number left, Number right) + { + return new Double(left.doubleValue() / right.doubleValue()); + } + + protected Number mod(Number left, Number right) + { + return new Double(left.doubleValue() % right.doubleValue()); + } + + private int numberType(Number left, Number right) + { + if (isDouble(left) || isDouble(right)) + { + return ArithmeticExpression.DOUBLE; + } + else if ((left instanceof Long) || (right instanceof Long)) + { + return ArithmeticExpression.LONG; + } + else + { + return ArithmeticExpression.INTEGER; + } + } + + private boolean isDouble(Number n) + { + return (n instanceof Float) || (n instanceof Double); + } + + protected Number asNumber(Object value) + { + if (value instanceof Number) + { + return (Number) value; + } + else + { + throw new RuntimeException("Cannot convert value: " + value + " into a number"); + } + } + + public Object evaluate(AbstractJMSMessage message) throws AMQInternalException + { + Object lvalue = left.evaluate(message); + if (lvalue == null) + { + return null; + } + + Object rvalue = right.evaluate(message); + if (rvalue == null) + { + return null; + } + + return evaluate(lvalue, rvalue); + } + + /** + * @param lvalue + * @param rvalue + * @return + */ + protected abstract Object evaluate(Object lvalue, Object rvalue); + +} diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/BinaryExpression.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/BinaryExpression.java new file mode 100644 index 0000000000..f97f858fad --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/BinaryExpression.java @@ -0,0 +1,103 @@ +/* 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; + +/** + * An expression which performs an operation on two expression values. + */ +public abstract class BinaryExpression implements Expression +{ + protected Expression left; + protected Expression right; + + public BinaryExpression(Expression left, Expression right) + { + this.left = left; + this.right = right; + } + + public Expression getLeft() + { + return left; + } + + public Expression getRight() + { + return right; + } + + /** + * @see Object#toString() + */ + public String toString() + { + return "(" + left.toString() + " " + getExpressionSymbol() + " " + right.toString() + ")"; + } + + /** + * TODO: more efficient hashCode() + * + * @see Object#hashCode() + */ + public int hashCode() + { + return toString().hashCode(); + } + + /** + * TODO: more efficient hashCode() + * + * @see Object#equals(Object) + */ + public boolean equals(Object o) + { + + if ((o == null) || !this.getClass().equals(o.getClass())) + { + return false; + } + + return toString().equals(o.toString()); + + } + + /** + * Returns the symbol that represents this binary expression. For example, addition is + * represented by "+" + * + * @return + */ + public abstract String getExpressionSymbol(); + + /** + * @param expression + */ + public void setRight(Expression expression) + { + right = expression; + } + + /** + * @param expression + */ + public void setLeft(Expression expression) + { + left = expression; + } + +} diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/BooleanExpression.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/BooleanExpression.java new file mode 100644 index 0000000000..14a5c7ea87 --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/BooleanExpression.java @@ -0,0 +1,33 @@ +/* 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; + +import org.apache.qpid.AMQInternalException; +import org.apache.qpid.client.message.AbstractJMSMessage; + + +/** + * A BooleanExpression is an expression that always + * produces a Boolean result. + */ +public interface BooleanExpression extends Expression +{ + + public boolean matches(AbstractJMSMessage message) throws AMQInternalException; + +} diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/ComparisonExpression.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/ComparisonExpression.java new file mode 100644 index 0000000000..55fca853ef --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/ComparisonExpression.java @@ -0,0 +1,589 @@ +/* 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; + +import java.util.HashSet; +import java.util.List; +import java.util.regex.Pattern; + +import org.apache.qpid.AMQInternalException; +import org.apache.qpid.client.message.AbstractJMSMessage; + +/** + * 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(ComparisonExpression.createGreaterThanEqual(value, left), ComparisonExpression.createLessThanEqual(value, right)); + } + + public static BooleanExpression createNotBetween(Expression value, Expression left, Expression right) + { + return LogicExpression.createOR(ComparisonExpression.createLessThan(value, left), ComparisonExpression.createGreaterThan(value, right)); + } + + private static final HashSet REGEXP_CONTROL_CHARS = new HashSet(); + + static + { + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('.')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('\\')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('[')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character(']')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('^')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('$')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('?')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('*')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('+')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('{')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('}')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('|')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('(')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character(')')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character(':')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('&')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('<')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('>')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('=')); + ComparisonExpression.REGEXP_CONTROL_CHARS.add(new Character('!')); + } + + 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 (ComparisonExpression.REGEXP_CONTROL_CHARS.contains(new Character(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(AbstractJMSMessage message) throws AMQInternalException + { + + 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(AbstractJMSMessage message) throws AMQInternalException + { + 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(ComparisonExpression.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 ComparisonExpression.doCreateEqual(left, ConstantExpression.NULL); + } + + public static BooleanExpression createIsNotNull(Expression left) + { + return UnaryExpression.createNOT(ComparisonExpression.doCreateEqual(left, ConstantExpression.NULL)); + } + + public static BooleanExpression createNotEqual(Expression left, Expression right) + { + return UnaryExpression.createNOT(ComparisonExpression.createEqual(left, right)); + } + + public static BooleanExpression createEqual(Expression left, Expression right) + { + ComparisonExpression.checkEqualOperand(left); + ComparisonExpression.checkEqualOperand(right); + ComparisonExpression.checkEqualOperandCompatability(left, right); + + return ComparisonExpression.doCreateEqual(left, right); + } + + private static BooleanExpression doCreateEqual(Expression left, Expression right) + { + return new ComparisonExpression(left, right) + { + + public Object evaluate(AbstractJMSMessage message) throws AMQInternalException + { + 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 "="; + } + }; + } + + public static BooleanExpression createGreaterThan(final Expression left, final Expression right) + { + ComparisonExpression.checkLessThanOperand(left); + ComparisonExpression.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) + { + ComparisonExpression.checkLessThanOperand(left); + ComparisonExpression.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) + { + ComparisonExpression.checkLessThanOperand(left); + ComparisonExpression.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) + { + ComparisonExpression.checkLessThanOperand(left); + ComparisonExpression.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(AbstractJMSMessage message) throws AMQInternalException + { + 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 = new Short(((Number) lv).shortValue()); + } + else if (rc == Integer.class) + { + lv = new Integer(((Number) lv).intValue()); + } + else if (rc == Long.class) + { + lv = new Long(((Number) lv).longValue()); + } + else if (rc == Float.class) + { + lv = new Float(((Number) lv).floatValue()); + } + else if (rc == Double.class) + { + lv = new Double(((Number) lv).doubleValue()); + } + else + { + return Boolean.FALSE; + } + } + else if (lc == Short.class) + { + if (rc == Integer.class) + { + lv = new Integer(((Number) lv).intValue()); + } + else if (rc == Long.class) + { + lv = new Long(((Number) lv).longValue()); + } + else if (rc == Float.class) + { + lv = new Float(((Number) lv).floatValue()); + } + else if (rc == Double.class) + { + lv = new Double(((Number) lv).doubleValue()); + } + else + { + return Boolean.FALSE; + } + } + else if (lc == Integer.class) + { + if (rc == Long.class) + { + lv = new Long(((Number) lv).longValue()); + } + else if (rc == Float.class) + { + lv = new Float(((Number) lv).floatValue()); + } + else if (rc == Double.class) + { + lv = new Double(((Number) lv).doubleValue()); + } + else + { + return Boolean.FALSE; + } + } + else if (lc == Long.class) + { + if (rc == Integer.class) + { + rv = new Long(((Number) rv).longValue()); + } + else if (rc == Float.class) + { + lv = new Float(((Number) lv).floatValue()); + } + else if (rc == Double.class) + { + lv = new Double(((Number) lv).doubleValue()); + } + else + { + return Boolean.FALSE; + } + } + else if (lc == Float.class) + { + if (rc == Integer.class) + { + rv = new Float(((Number) rv).floatValue()); + } + else if (rc == Long.class) + { + rv = new Float(((Number) rv).floatValue()); + } + else if (rc == Double.class) + { + lv = new Double(((Number) lv).doubleValue()); + } + else + { + return Boolean.FALSE; + } + } + else if (lc == Double.class) + { + if (rc == Integer.class) + { + rv = new Double(((Number) rv).doubleValue()); + } + else if (rc == Long.class) + { + rv = new Double(((Number) rv).doubleValue()); + } + else if (rc == Float.class) + { + rv = new Float(((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(AbstractJMSMessage message) throws AMQInternalException + { + Object object = evaluate(message); + + return (object != null) && (object == Boolean.TRUE); + } + +} diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/ConstantExpression.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/ConstantExpression.java new file mode 100644 index 0000000000..3874d13431 --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/ConstantExpression.java @@ -0,0 +1,204 @@ +/* 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; + +import java.math.BigDecimal; + +import org.apache.qpid.AMQInternalException; +import org.apache.qpid.client.message.AbstractJMSMessage; + +/** + * Represents a constant expression + */ +public class ConstantExpression implements Expression +{ + + static class BooleanConstantExpression extends ConstantExpression implements BooleanExpression + { + public BooleanConstantExpression(Object value) + { + super(value); + } + + public boolean matches(AbstractJMSMessage message) throws AMQInternalException + { + Object object = evaluate(message); + + return (object != null) && (object == Boolean.TRUE); + } + } + + public static final BooleanConstantExpression NULL = new BooleanConstantExpression(null); + public static final BooleanConstantExpression TRUE = new BooleanConstantExpression(Boolean.TRUE); + public static final BooleanConstantExpression FALSE = new BooleanConstantExpression(Boolean.FALSE); + + private Object value; + + public static ConstantExpression createFromDecimal(String text) + { + + // Strip off the 'l' or 'L' if needed. + if (text.endsWith("l") || text.endsWith("L")) + { + text = text.substring(0, text.length() - 1); + } + + Number value; + try + { + value = new Long(text); + } + catch (NumberFormatException e) + { + // The number may be too big to fit in a long. + value = new BigDecimal(text); + } + + long l = value.longValue(); + if ((Integer.MIN_VALUE <= l) && (l <= Integer.MAX_VALUE)) + { + value = new Integer(value.intValue()); + } + + return new ConstantExpression(value); + } + + public static ConstantExpression createFromHex(String text) + { + Number value = new Long(Long.parseLong(text.substring(2), 16)); + long l = value.longValue(); + if ((Integer.MIN_VALUE <= l) && (l <= Integer.MAX_VALUE)) + { + value = new Integer(value.intValue()); + } + + return new ConstantExpression(value); + } + + public static ConstantExpression createFromOctal(String text) + { + Number value = new Long(Long.parseLong(text, 8)); + long l = value.longValue(); + if ((Integer.MIN_VALUE <= l) && (l <= Integer.MAX_VALUE)) + { + value = new Integer(value.intValue()); + } + + return new ConstantExpression(value); + } + + public static ConstantExpression createFloat(String text) + { + Number value = new Double(text); + + return new ConstantExpression(value); + } + + public ConstantExpression(Object value) + { + this.value = value; + } + + public Object evaluate(AbstractJMSMessage message) throws AMQInternalException + { + return value; + } + + public Object getValue() + { + return value; + } + + /** + * @see Object#toString() + */ + public String toString() + { + if (value == null) + { + return "NULL"; + } + + if (value instanceof Boolean) + { + return ((Boolean) value).booleanValue() ? "TRUE" : "FALSE"; + } + + if (value instanceof String) + { + return ConstantExpression.encodeString((String) value); + } + + return value.toString(); + } + + /** + * TODO: more efficient hashCode() + * + * @see Object#hashCode() + */ + public int hashCode() + { + return toString().hashCode(); + } + + /** + * TODO: more efficient hashCode() + * + * @see Object#equals(Object) + */ + public boolean equals(Object o) + { + + if ((o == null) || !this.getClass().equals(o.getClass())) + { + return false; + } + + return toString().equals(o.toString()); + + } + + /** + * Encodes the value of string so that it looks like it would look like + * when it was provided in a selector. + * + * @param s + * @return + */ + public static String encodeString(String s) + { + StringBuffer b = new StringBuffer(); + b.append('\''); + for (int i = 0; i < s.length(); i++) + { + char c = s.charAt(i); + if (c == '\'') + { + b.append(c); + } + + b.append(c); + } + + b.append('\''); + + return b.toString(); + } + +} diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/Expression.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/Expression.java new file mode 100644 index 0000000000..8208f49688 --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/Expression.java @@ -0,0 +1,35 @@ +/* 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; + +import org.apache.qpid.AMQInternalException; +import org.apache.qpid.client.message.AbstractJMSMessage; + + +/** + * Represents an expression + */ +public interface Expression +{ + /** + * @param message The message to evaluate + * @return the value of this expression + * @throws AMQInternalException + */ + public Object evaluate(AbstractJMSMessage message) throws AMQInternalException; +} diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/JMSSelectorFilter.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/JMSSelectorFilter.java new file mode 100644 index 0000000000..4159986090 --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/JMSSelectorFilter.java @@ -0,0 +1,70 @@ +/* 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; + +import org.apache.qpid.AMQInternalException; +import org.apache.qpid.client.message.AbstractJMSMessage; +import org.apache.qpid.filter.selector.SelectorParser; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + + +public class JMSSelectorFilter implements MessageFilter +{ + /** + * this JMSSelectorFilter's logger + */ + private static final Logger _logger = LoggerFactory.getLogger(JMSSelectorFilter.class); + + private String _selector; + private BooleanExpression _matcher; + + public JMSSelectorFilter(String selector) throws AMQInternalException + { + _selector = selector; + if (JMSSelectorFilter._logger.isDebugEnabled()) + { + JMSSelectorFilter._logger.debug("Created JMSSelectorFilter with selector:" + _selector); + } + _matcher = new SelectorParser().parse(selector); + } + + public boolean matches(AbstractJMSMessage message) + { + try + { + boolean match = _matcher.matches(message); + if (JMSSelectorFilter._logger.isDebugEnabled()) + { + JMSSelectorFilter._logger.debug(message + " match(" + match + ") selector(" + System + .identityHashCode(_selector) + "):" + _selector); + } + return match; + } + catch (AMQInternalException e) + { + JMSSelectorFilter._logger.warn("Caght exception when evaluating message selector for message " + message, e); + } + return false; + } + + public String getSelector() + { + return _selector; + } +} diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/LogicExpression.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/LogicExpression.java new file mode 100644 index 0000000000..7ef85cbacb --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/LogicExpression.java @@ -0,0 +1,108 @@ +/* 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; + +import org.apache.qpid.AMQInternalException; +import org.apache.qpid.client.message.AbstractJMSMessage; + + +/** + * A filter performing a comparison of two objects + */ +public abstract class LogicExpression extends BinaryExpression implements BooleanExpression +{ + + public static BooleanExpression createOR(BooleanExpression lvalue, BooleanExpression rvalue) + { + return new LogicExpression(lvalue, rvalue) + { + + public Object evaluate(AbstractJMSMessage message) throws AMQInternalException + { + + Boolean lv = (Boolean) left.evaluate(message); + // Can we do an OR shortcut?? + if ((lv != null) && lv.booleanValue()) + { + return Boolean.TRUE; + } + + Boolean rv = (Boolean) right.evaluate(message); + + return (rv == null) ? null : rv; + } + + public String getExpressionSymbol() + { + return "OR"; + } + }; + } + + public static BooleanExpression createAND(BooleanExpression lvalue, BooleanExpression rvalue) + { + return new LogicExpression(lvalue, rvalue) + { + + public Object evaluate(AbstractJMSMessage message) throws AMQInternalException + { + + Boolean lv = (Boolean) left.evaluate(message); + + // Can we do an AND shortcut?? + if (lv == null) + { + return null; + } + + if (!lv.booleanValue()) + { + return Boolean.FALSE; + } + + Boolean rv = (Boolean) right.evaluate(message); + + return (rv == null) ? null : rv; + } + + public String getExpressionSymbol() + { + return "AND"; + } + }; + } + + /** + * @param left + * @param right + */ + public LogicExpression(BooleanExpression left, BooleanExpression right) + { + super(left, right); + } + + public abstract Object evaluate(AbstractJMSMessage message) throws AMQInternalException; + + public boolean matches(AbstractJMSMessage message) throws AMQInternalException + { + Object object = evaluate(message); + + return (object != null) && (object == Boolean.TRUE); + } + +} diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/MessageFilter.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/MessageFilter.java new file mode 100644 index 0000000000..62e4a28c1e --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/MessageFilter.java @@ -0,0 +1,27 @@ +/* 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; + +import org.apache.qpid.AMQInternalException; +import org.apache.qpid.client.message.AbstractJMSMessage; + + +public interface MessageFilter +{ + boolean matches(AbstractJMSMessage message) throws AMQInternalException; +} diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/PropertyExpression.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/PropertyExpression.java new file mode 100644 index 0000000000..b7b6bd57bc --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/PropertyExpression.java @@ -0,0 +1,297 @@ +/* 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; + +import java.util.HashMap; + +import javax.jms.JMSException; + +import org.apache.qpid.AMQInternalException; +import org.apache.qpid.client.message.AbstractJMSMessage; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Represents a property expression + */ +public class PropertyExpression implements Expression +{ + // Constants - defined the same as JMS + private static final int NON_PERSISTENT = 1; + private static final int DEFAULT_PRIORITY = 4; + + private static final Logger _logger = LoggerFactory.getLogger(PropertyExpression.class); + + private static final HashMap<String, Expression> JMS_PROPERTY_EXPRESSIONS = new HashMap<String, Expression>(); + + static + { + JMS_PROPERTY_EXPRESSIONS.put("JMSDestination", new Expression() + { + public Object evaluate(AbstractJMSMessage message) + { + //TODO + return null; + } + }); + JMS_PROPERTY_EXPRESSIONS.put("JMSReplyTo", new Expression() + { + public Object evaluate(AbstractJMSMessage message) + { + return message.getReplyToString(); + } + }); + + JMS_PROPERTY_EXPRESSIONS.put("JMSType", new Expression() + { + public Object evaluate(AbstractJMSMessage message) + { + try + { + return message.getJMSType(); + } + catch (JMSException e) + { + _logger.warn("Error evaluating property", e); + + return null; + } + + } + }); + + JMS_PROPERTY_EXPRESSIONS.put("JMSDeliveryMode", new Expression() + { + public Object evaluate(AbstractJMSMessage message) + { + try + { + int mode = message.getJMSDeliveryMode(); + if (_logger.isDebugEnabled()) + { + _logger.debug("JMSDeliveryMode is :" + mode); + } + + return mode; + } + catch (JMSException e) + { + _logger.warn("Error evaluating property",e); + } + + return NON_PERSISTENT; + } + }); + + JMS_PROPERTY_EXPRESSIONS.put("JMSPriority", new Expression() + { + public Object evaluate(AbstractJMSMessage message) + { + try + { + return message.getJMSPriority(); + } + catch (Exception e) + { + _logger.warn("Error evaluating property",e); + } + + return DEFAULT_PRIORITY; + } + }); + + JMS_PROPERTY_EXPRESSIONS.put("AMQMessageID", new Expression() + { + public Object evaluate(AbstractJMSMessage message) + { + + try + { + return message.getJMSMessageID(); + } + catch (JMSException e) + { + _logger.warn("Error evaluating property",e); + + return null; + } + + } + }); + + JMS_PROPERTY_EXPRESSIONS.put("JMSTimestamp", new Expression() + { + public Object evaluate(AbstractJMSMessage message) + { + try + { + return message.getJMSTimestamp(); + } + catch (Exception e) + { + _logger.warn("Error evaluating property",e); + + return null; + } + + } + }); + + JMS_PROPERTY_EXPRESSIONS.put("JMSCorrelationID", new Expression() + { + public Object evaluate(AbstractJMSMessage message) + { + + try + { + return message.getJMSCorrelationID(); + } + catch (JMSException e) + { + _logger.warn("Error evaluating property",e); + + return null; + } + + } + }); + + JMS_PROPERTY_EXPRESSIONS.put("JMSExpiration", new Expression() + { + public Object evaluate(AbstractJMSMessage message) + { + + try + { + return message.getJMSExpiration(); + } + catch (JMSException e) + { + _logger.warn("Error evaluating property",e); + return null; + } + + } + }); + + JMS_PROPERTY_EXPRESSIONS.put("JMSRedelivered", new Expression() + { + public Object evaluate(AbstractJMSMessage message) + { + try + { + return message.getJMSRedelivered(); + } + catch (JMSException e) + { + _logger.warn("Error evaluating property",e); + return null; + } + } + }); + + JMS_PROPERTY_EXPRESSIONS.put("JMSMessageID", new Expression() + { + public Object evaluate(AbstractJMSMessage message) + { + try + { + return message.getJMSMessageID(); + } + catch (Exception e) + { + _logger.warn("Error evaluating property",e); + + return null; + } + + } + }); + + } + + private final String name; + private final Expression jmsPropertyExpression; + + public PropertyExpression(String name) + { + this.name = name; + jmsPropertyExpression = JMS_PROPERTY_EXPRESSIONS.get(name); + } + + public Object evaluate(AbstractJMSMessage message) throws AMQInternalException + { + + if (jmsPropertyExpression != null) + { + return jmsPropertyExpression.evaluate(message); + } + else + { + + try + { + + if (_logger.isDebugEnabled()) + { + _logger.debug("Looking up property:" + name); + _logger.debug("Properties are:" + message.getPropertyNames()); + } + return message.getObjectProperty(name); + } + catch(JMSException e) + { + throw new AMQInternalException("Exception evaluating properties for filter", e); + } + } + } + + public String getName() + { + return name; + } + + /** + * @see java.lang.Object#toString() + */ + public String toString() + { + return name; + } + + /** + * @see java.lang.Object#hashCode() + */ + public int hashCode() + { + return name.hashCode(); + } + + /** + * @see java.lang.Object#equals(java.lang.Object) + */ + public boolean equals(Object o) + { + if ((o == null) || !this.getClass().equals(o.getClass())) + { + return false; + } + return name.equals(((PropertyExpression) o).name); + } + +} diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/UnaryExpression.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/UnaryExpression.java new file mode 100644 index 0000000000..0fc3382b7e --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/UnaryExpression.java @@ -0,0 +1,321 @@ +/* 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; + +import java.math.BigDecimal; +import java.util.Collection; +import java.util.HashSet; +import java.util.Iterator; +import java.util.List; + +import org.apache.qpid.AMQInternalException; +import org.apache.qpid.client.message.AbstractJMSMessage; + +/** + * 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); + protected Expression right; + + public static Expression createNegate(Expression left) + { + return new UnaryExpression(left) + { + public Object evaluate(AbstractJMSMessage message) throws AMQInternalException + { + Object rvalue = right.evaluate(message); + if (rvalue == null) + { + return null; + } + + if (rvalue instanceof Number) + { + return UnaryExpression.negate((Number) rvalue); + } + + return null; + } + + public String getExpressionSymbol() + { + return "-"; + } + }; + } + + 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 BooleanUnaryExpression(right) + { + public Object evaluate(AbstractJMSMessage message) throws AMQInternalException + { + + Object rvalue = right.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() + { + StringBuffer answer = new StringBuffer(); + answer.append(right); + answer.append(" "); + answer.append(getExpressionSymbol()); + answer.append(" ( "); + + int count = 0; + for (Iterator i = inList.iterator(); i.hasNext();) + { + Object o = (Object) i.next(); + 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"; + } + } + }; + } + + abstract static class BooleanUnaryExpression extends UnaryExpression implements BooleanExpression + { + public BooleanUnaryExpression(Expression left) + { + super(left); + } + + public boolean matches(AbstractJMSMessage message) throws AMQInternalException + { + Object object = evaluate(message); + + return (object != null) && (object == Boolean.TRUE); + } + } + + ; + + public static BooleanExpression createNOT(BooleanExpression left) + { + return new BooleanUnaryExpression(left) + { + public Object evaluate(AbstractJMSMessage message) throws AMQInternalException + { + Boolean lvalue = (Boolean) right.evaluate(message); + if (lvalue == null) + { + return null; + } + + return lvalue.booleanValue() ? Boolean.FALSE : Boolean.TRUE; + } + + public String getExpressionSymbol() + { + return "NOT"; + } + }; + } + public static BooleanExpression createBooleanCast(Expression left) + { + return new BooleanUnaryExpression(left) + { + public Object evaluate(AbstractJMSMessage message) throws AMQInternalException + { + Object rvalue = right.evaluate(message); + if (rvalue == null) + { + return null; + } + + if (!rvalue.getClass().equals(Boolean.class)) + { + return Boolean.FALSE; + } + + return ((Boolean) rvalue).booleanValue() ? Boolean.TRUE : Boolean.FALSE; + } + + public String toString() + { + return right.toString(); + } + + public String getExpressionSymbol() + { + return ""; + } + }; + } + + private static Number negate(Number left) + { + Class clazz = left.getClass(); + if (clazz == Integer.class) + { + return new Integer(-left.intValue()); + } + else if (clazz == Long.class) + { + return new Long(-left.longValue()); + } + else if (clazz == Float.class) + { + return new Float(-left.floatValue()); + } + else if (clazz == Double.class) + { + return new Double(-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 (UnaryExpression.BD_LONG_MIN_VALUE.compareTo(bd) == 0) + { + return new Long(Long.MIN_VALUE); + } + + return bd; + } + else + { + throw new RuntimeException("Don't know how to negate: " + left); + } + } + + public UnaryExpression(Expression left) + { + this.right = left; + } + + public Expression getRight() + { + return right; + } + + public void setRight(Expression expression) + { + right = expression; + } + + /** + * @see Object#toString() + */ + public String toString() + { + return "(" + getExpressionSymbol() + " " + right.toString() + ")"; + } + + /** + * TODO: more efficient hashCode() + * + * @see Object#hashCode() + */ + public int hashCode() + { + return toString().hashCode(); + } + + /** + * TODO: more efficient hashCode() + * + * @see Object#equals(Object) + */ + public boolean equals(Object o) + { + + if ((o == null) || !this.getClass().equals(o.getClass())) + { + return false; + } + + return toString().equals(o.toString()); + + } + + /** + * Returns the symbol that represents this binary expression. For example, addition is + * represented by "+" + * + * @return + */ + public abstract String getExpressionSymbol(); + +} |