| /** |
| * 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.camel.builder; |
| |
| import org.apache.camel.BinaryPredicate; |
| import org.apache.camel.Exchange; |
| import org.apache.camel.Expression; |
| import org.apache.camel.Predicate; |
| |
| import static org.apache.camel.util.ObjectHelper.notNull; |
| |
| /** |
| * A useful base class for {@link Predicate} implementations |
| * |
| * @version |
| */ |
| public abstract class BinaryPredicateSupport implements BinaryPredicate { |
| |
| private final Expression left; |
| private final Expression right; |
| |
| protected BinaryPredicateSupport(Expression left, Expression right) { |
| notNull(left, "left"); |
| notNull(right, "right"); |
| |
| this.left = left; |
| this.right = right; |
| } |
| |
| @Override |
| public String toString() { |
| return left + " " + getOperationText() + " " + right; |
| } |
| |
| public boolean matches(Exchange exchange) { |
| return matchesReturningFailureMessage(exchange) == null; |
| } |
| |
| public String matchesReturningFailureMessage(Exchange exchange) { |
| // we must not store any state, so we can be thread safe |
| // and thus we offer this method which returns a failure message if |
| // we did not match |
| String answer = null; |
| |
| // must be thread safe and store result in local objects |
| Object leftValue = left.evaluate(exchange, Object.class); |
| Object rightValue = right.evaluate(exchange, Object.class); |
| if (!matches(exchange, leftValue, rightValue)) { |
| answer = leftValue + " " + getOperator() + " " + rightValue; |
| } |
| |
| return answer; |
| } |
| |
| protected abstract boolean matches(Exchange exchange, Object leftValue, Object rightValue); |
| |
| protected abstract String getOperationText(); |
| |
| public Expression getLeft() { |
| return left; |
| } |
| |
| public Expression getRight() { |
| return right; |
| } |
| |
| public String getOperator() { |
| return getOperationText(); |
| } |
| |
| } |