| /** |
| * 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.language.ref; |
| |
| import org.apache.camel.Exchange; |
| import org.apache.camel.Expression; |
| import org.apache.camel.IsSingleton; |
| import org.apache.camel.Predicate; |
| import org.apache.camel.builder.ExpressionBuilder; |
| import org.apache.camel.builder.PredicateBuilder; |
| import org.apache.camel.impl.ExpressionAdapter; |
| import org.apache.camel.spi.Language; |
| |
| /** |
| * A language for referred expressions. |
| */ |
| public class RefLanguage implements Language, IsSingleton { |
| |
| public static Expression ref(Object value) { |
| String ref = value.toString(); |
| return ExpressionBuilder.refExpression(ref); |
| } |
| |
| public Predicate createPredicate(String expression) { |
| return PredicateBuilder.toPredicate(createExpression(expression)); |
| } |
| |
| public Expression createExpression(final String expression) { |
| final Expression exp = RefLanguage.ref(expression); |
| return new ExpressionAdapter() { |
| public Object evaluate(Exchange exchange) { |
| Expression lookup = exp.evaluate(exchange, Expression.class); |
| if (lookup != null) { |
| return lookup.evaluate(exchange, Object.class); |
| } else { |
| throw new IllegalArgumentException("Cannot find expression in registry with ref: " + expression); |
| } |
| } |
| |
| public String toString() { |
| return exp.toString(); |
| } |
| }; |
| } |
| |
| public boolean isSingleton() { |
| return true; |
| } |
| } |