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.impl.converter; 018 019 import java.util.concurrent.ExecutionException; 020 import java.util.concurrent.Future; 021 022 import org.apache.camel.Converter; 023 import org.apache.camel.Exchange; 024 import org.apache.camel.NoTypeConversionAvailableException; 025 import org.apache.camel.StreamCache; 026 import org.apache.camel.TypeConverter; 027 import org.apache.camel.util.ExchangeHelper; 028 import org.apache.camel.util.ObjectHelper; 029 import org.apache.commons.logging.Log; 030 import org.apache.commons.logging.LogFactory; 031 032 /** 033 * Future type converter. 034 * 035 * @version $Revision: 772853 $ 036 */ 037 @Converter 038 public final class FutureTypeConverter implements TypeConverter { 039 040 private static final Log LOG = LogFactory.getLog(FutureTypeConverter.class); 041 042 private final TypeConverter converter; 043 044 public FutureTypeConverter(TypeConverter converter) { 045 this.converter = converter; 046 } 047 048 private <T> T doConvertTo(Class<T> type, Exchange exchange, Object value) throws Exception { 049 // do not convert to stream cache 050 if (StreamCache.class.isAssignableFrom(value.getClass())) { 051 return null; 052 } 053 054 if (Future.class.isAssignableFrom(value.getClass())) { 055 056 Future future = (Future) value; 057 058 if (future.isCancelled()) { 059 return null; 060 } 061 062 // do some trace logging as the get is blocking until the response is ready 063 if (LOG.isTraceEnabled()) { 064 LOG.trace("Getting future response"); 065 } 066 067 Object body; 068 try { 069 body = future.get(); 070 } catch (ExecutionException e) { 071 if (e.getCause() instanceof Exception) { 072 throw (Exception) e.getCause(); 073 } else { 074 throw e; 075 } 076 } 077 if (LOG.isTraceEnabled()) { 078 LOG.trace("Got future response"); 079 } 080 081 if (body == null) { 082 return null; 083 } 084 085 // maybe from is already the type we want 086 if (type.isAssignableFrom(body.getClass())) { 087 return type.cast(body); 088 } else if (body instanceof Exchange) { 089 Exchange result = (Exchange) body; 090 body = ExchangeHelper.extractResultBody(result, result.getPattern()); 091 } 092 093 // no then try to lookup a type converter 094 return converter.convertTo(type, exchange, body); 095 } 096 097 return null; 098 } 099 100 public <T> T convertTo(Class<T> type, Object value) { 101 return convertTo(type, null, value); 102 } 103 104 public <T> T convertTo(Class<T> type, Exchange exchange, Object value) { 105 try { 106 return doConvertTo(type, exchange, value); 107 } catch (Exception e) { 108 throw ObjectHelper.wrapRuntimeCamelException(e); 109 } 110 } 111 112 public <T> T mandatoryConvertTo(Class<T> type, Object value) throws NoTypeConversionAvailableException { 113 return mandatoryConvertTo(type, null, value); 114 } 115 116 public <T> T mandatoryConvertTo(Class<T> type, Exchange exchange, Object value) throws NoTypeConversionAvailableException { 117 T answer; 118 try { 119 answer = doConvertTo(type, exchange, value); 120 } catch (Exception e) { 121 throw new NoTypeConversionAvailableException(value, type, e); 122 } 123 124 if (answer == null) { 125 throw new NoTypeConversionAvailableException(value, type); 126 } 127 128 return answer; 129 } 130 }