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.spi.TypeConverterRegistry;
024    import org.apache.camel.support.TypeConverterSupport;
025    import org.apache.camel.util.ObjectHelper;
026    
027    /**
028     * A {@link org.apache.camel.TypeConverter} implementation which instantiates an object
029     * so that an instance method can be used as a fallback type converter
030     *
031     * @version 
032     */
033    public class InstanceMethodFallbackTypeConverter extends TypeConverterSupport {
034        private final CachingInjector<?> injector;
035        private final Method method;
036        private final boolean useExchange;
037        private final TypeConverterRegistry registry;
038        private final boolean allowNull;
039    
040        @Deprecated
041        public InstanceMethodFallbackTypeConverter(CachingInjector<?> injector, Method method, TypeConverterRegistry registry) {
042            this(injector, method, registry, false);
043        }
044    
045        public InstanceMethodFallbackTypeConverter(CachingInjector<?> injector, Method method, TypeConverterRegistry registry, boolean allowNull) {
046            this.injector = injector;
047            this.method = method;
048            this.useExchange = method.getParameterTypes().length == 4;
049            this.registry = registry;
050            this.allowNull = allowNull;
051        }
052    
053        @Override
054        public String toString() {
055            return "InstanceMethodFallbackTypeConverter: " + method;
056        }
057    
058        @Override
059        public boolean allowNull() {
060            return allowNull;
061        }
062    
063        @SuppressWarnings("unchecked")
064        public <T> T convertTo(Class<T> type, Exchange exchange, Object value) {
065            Object instance = injector.newInstance();
066            if (instance == null) {
067                throw new RuntimeCamelException("Could not instantiate an instance of: " + type.getCanonicalName());
068            }
069            return useExchange
070                ? (T)ObjectHelper.invokeMethod(method, instance, type, exchange, value, registry) : (T)ObjectHelper
071                    .invokeMethod(method, instance, type, value, registry);
072        }
073    
074    }