001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.component.language;
018
019 import java.io.InputStream;
020
021 import org.apache.camel.CamelExchangeException;
022 import org.apache.camel.Exchange;
023 import org.apache.camel.Expression;
024 import org.apache.camel.impl.DefaultProducer;
025 import org.apache.camel.util.IOHelper;
026 import org.apache.camel.util.ObjectHelper;
027 import org.apache.camel.util.ResourceHelper;
028 import org.apache.camel.util.ServiceHelper;
029
030 /**
031 * Language producer.
032 *
033 * @version
034 */
035 public class LanguageProducer extends DefaultProducer {
036
037 public LanguageProducer(LanguageEndpoint endpoint) {
038 super(endpoint);
039 }
040
041 public void process(Exchange exchange) throws Exception {
042 // is there a custom expression in the header?
043 Expression exp = exchange.getIn().getHeader(Exchange.LANGUAGE_SCRIPT, Expression.class);
044 if (exp == null) {
045 String script = exchange.getIn().getHeader(Exchange.LANGUAGE_SCRIPT, String.class);
046 if (script != null) {
047 // the script may be a file: so resolve it before using
048 script = getEndpoint().resolveScript(script);
049 exp = getEndpoint().getLanguage().createExpression(script);
050 }
051 }
052 // if not fallback to use expression from endpoint
053 if (exp == null && getEndpoint().isCacheScript()) {
054 exp = getEndpoint().getExpression();
055 }
056
057 // fallback and use resource uri from endpoint
058 if (exp == null) {
059 String script = getEndpoint().getScript();
060
061 if (script == null && getEndpoint().getResourceUri() == null) {
062 // no script to execute
063 throw new CamelExchangeException("No script to evaluate", exchange);
064 }
065
066 // the script can be a resource from the endpoint,
067 // or refer to a resource itself
068 // or just be a plain string
069 InputStream is = null;
070 if (script == null) {
071 is = getEndpoint().getResourceAsInputStream();
072 } else if (ResourceHelper.hasScheme(script)) {
073 is = ResourceHelper.resolveMandatoryResourceAsInputStream(getEndpoint().getCamelContext().getClassResolver(), script);
074 }
075 if (is != null) {
076 try {
077 script = getEndpoint().getCamelContext().getTypeConverter().convertTo(String.class, exchange, is);
078 } finally {
079 IOHelper.close(is);
080 }
081 }
082
083 if (script != null) {
084 // create the expression from the script
085 exp = getEndpoint().getLanguage().createExpression(script);
086 // expression was resolved from resource
087 getEndpoint().setContentResolvedFromResource(true);
088 // if we cache then set this as expression on endpoint so we don't re-create it again
089 if (getEndpoint().isCacheScript()) {
090 getEndpoint().setExpression(exp);
091 }
092 } else {
093 // no script to execute
094 throw new CamelExchangeException("No script to evaluate", exchange);
095 }
096 }
097
098 ObjectHelper.notNull(exp, "expression");
099
100 Object result;
101 try {
102 result = exp.evaluate(exchange, Object.class);
103 log.debug("Evaluated expression as: {} with: {}", result, exchange);
104 } finally {
105 if (!getEndpoint().isCacheScript()) {
106 // some languages add themselves as a service which we then need to remove if we are not cached
107 ServiceHelper.stopService(exp);
108 getEndpoint().getCamelContext().removeService(exp);
109 }
110 }
111
112 // set message body if transform is enabled
113 if (getEndpoint().isTransform()) {
114 if (exchange.hasOut()) {
115 exchange.getOut().setBody(result);
116 } else {
117 exchange.getIn().setBody(result);
118 }
119 }
120 }
121
122 @Override
123 public LanguageEndpoint getEndpoint() {
124 return (LanguageEndpoint) super.getEndpoint();
125 }
126 }