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.lang.reflect.Method;
020    
021    import org.apache.camel.Exchange;
022    import org.apache.camel.RuntimeCamelException;
023    import org.apache.camel.TypeConverter;
024    import org.apache.camel.spi.TypeConverterAware;
025    import org.apache.camel.spi.TypeConverterRegistry;
026    import org.apache.camel.support.TypeConverterSupport;
027    import org.apache.camel.util.ObjectHelper;
028    
029    /**
030     * A {@link TypeConverter} implementation which instantiates an object
031     * so that an instance method can be used as a type converter
032     *
033     * @version 
034     */
035    public class InstanceMethodTypeConverter extends TypeConverterSupport {
036        private final CachingInjector<?> injector;
037        private final Method method;
038        private final boolean useExchange;
039        private final TypeConverterRegistry registry;
040    
041        public InstanceMethodTypeConverter(CachingInjector<?> injector, Method method, TypeConverterRegistry registry) {
042            this.injector = injector;
043            this.method = method;
044            this.useExchange = method.getParameterTypes().length == 2;
045            this.registry = registry;
046        }
047    
048        @Override
049        public String toString() {
050            return "InstanceMethodTypeConverter: " + method;
051        }
052    
053        @SuppressWarnings("unchecked")
054        public <T> T convertTo(Class<T> type, Exchange exchange, Object value) {
055            Object instance = injector.newInstance();
056            if (instance == null) {
057                throw new RuntimeCamelException("Could not instantiate an instance of: " + type.getCanonicalName());
058            }
059            // inject parent type converter
060            if (instance instanceof TypeConverterAware) {
061                if (registry instanceof TypeConverter) {
062                    TypeConverter parentTypeConverter = (TypeConverter) registry;
063                    ((TypeConverterAware) instance).setTypeConverter(parentTypeConverter);
064                }
065            }
066            return useExchange
067                ? (T)ObjectHelper.invokeMethod(method, instance, value, exchange) : (T)ObjectHelper
068                    .invokeMethod(method, instance, value);
069        }
070    
071    }