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.util.ObjectHelper;
027    
028    /**
029     * A {@link TypeConverter} implementation which instantiates an object
030     * so that an instance method can be used as a type converter
031     *
032     * @version $Revision: 901136 $
033     */
034    public class InstanceMethodTypeConverter implements TypeConverter {
035        private final CachingInjector<?>injector;
036        private final Method method;
037        private final boolean useExchange;
038        private final TypeConverterRegistry registry;
039    
040        public InstanceMethodTypeConverter(CachingInjector<?> injector, Method method, TypeConverterRegistry registry) {
041            this.injector = injector;
042            this.method = method;
043            this.useExchange = method.getParameterTypes().length == 2;
044            this.registry = registry;
045        }
046    
047        @Override
048        public String toString() {
049            return "InstanceMethodTypeConverter: " + method;
050        }
051    
052        public <T> T convertTo(Class<T> type, Object value) {
053            return convertTo(type, null, value);
054        }
055    
056        @SuppressWarnings("unchecked")
057        public <T> T convertTo(Class<T> type, Exchange exchange, Object value) {
058            Object instance = injector.newInstance();
059            if (instance == null) {
060                throw new RuntimeCamelException("Could not instantiate an instance of: " + type.getCanonicalName());
061            }
062            // inject parent type converter
063            if (instance instanceof TypeConverterAware) {
064                if (registry instanceof TypeConverter) {
065                    TypeConverter parentTypeConverter = (TypeConverter) registry;
066                    ((TypeConverterAware) instance).setTypeConverter(parentTypeConverter);
067                }
068            }
069            return useExchange
070                ? (T)ObjectHelper.invokeMethod(method, instance, value, exchange) : (T)ObjectHelper
071                    .invokeMethod(method, instance, value);
072        }
073    
074        public <T> T mandatoryConvertTo(Class<T> type, Object value) {
075            return convertTo(type, null, value);
076        }
077    
078        public <T> T mandatoryConvertTo(Class<T> type, Exchange exchange, Object value) {
079            return convertTo(type, null, value);
080        }
081    }