| /** |
| * 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.jxpath; |
| |
| import org.apache.camel.Exchange; |
| import org.apache.camel.ExpressionEvaluationException; |
| import org.apache.camel.impl.ExpressionSupport; |
| import org.apache.commons.jxpath.CompiledExpression; |
| import org.apache.commons.jxpath.JXPathContext; |
| import org.apache.commons.jxpath.JXPathException; |
| |
| /** |
| * <a href="http://commons.apache.org/jxpath/">JXPath</a> {@link org.apache.camel.Expression} support |
| */ |
| public class JXPathExpression extends ExpressionSupport { |
| |
| private final String expression; |
| private CompiledExpression compiledExpression; |
| private final Class<?> type; |
| |
| /** |
| * Creates a new JXPathExpression instance |
| * |
| * @param expression the JXPath expression to be evaluated |
| * @param type the expected result type |
| */ |
| public JXPathExpression(String expression, Class<?> type) { |
| super(); |
| this.expression = expression; |
| this.type = type; |
| } |
| |
| public <T> T evaluate(Exchange exchange, Class<T> tClass) { |
| try { |
| JXPathContext context = JXPathContext.newContext(exchange); |
| Object result = getJXPathExpression().getValue(context, type); |
| assertResultType(exchange, result); |
| return exchange.getContext().getTypeConverter().convertTo(tClass, result); |
| } catch (JXPathException e) { |
| throw new ExpressionEvaluationException(this, exchange, e); |
| } |
| } |
| |
| /* |
| * Check if the result is of the specified type |
| */ |
| private void assertResultType(Exchange exchange, Object result) { |
| if (result != null && !type.isAssignableFrom(result.getClass())) { |
| throw new JXPathException("JXPath result type is " + result.getClass() + " instead of required type " + type); |
| } |
| } |
| |
| @Override |
| protected String assertionFailureMessage(Exchange exchange) { |
| return expression; |
| } |
| |
| /* |
| * Get a compiled expression instance for better performance |
| */ |
| private synchronized CompiledExpression getJXPathExpression() { |
| if (compiledExpression == null) { |
| compiledExpression = JXPathContext.compile(expression); |
| } |
| return compiledExpression; |
| } |
| |
| @Override |
| public String toString() { |
| return "JXpath[" + expression + "]"; |
| } |
| } |