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 */
017package org.apache.camel.impl.converter;
018
019import java.lang.reflect.Method;
020
021import org.apache.camel.Exchange;
022import org.apache.camel.RuntimeCamelException;
023import org.apache.camel.TypeConverter;
024import org.apache.camel.spi.TypeConverterAware;
025import org.apache.camel.spi.TypeConverterRegistry;
026import org.apache.camel.support.TypeConverterSupport;
027import 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 */
035public 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    private final boolean allowNull;
041
042    @Deprecated
043    public InstanceMethodTypeConverter(CachingInjector<?> injector, Method method, TypeConverterRegistry registry) {
044        this(injector, method, registry, false);
045    }
046
047    public InstanceMethodTypeConverter(CachingInjector<?> injector, Method method, TypeConverterRegistry registry, boolean allowNull) {
048        this.injector = injector;
049        this.method = method;
050        this.useExchange = method.getParameterTypes().length == 2;
051        this.registry = registry;
052        this.allowNull = allowNull;
053    }
054
055    @Override
056    public String toString() {
057        return "InstanceMethodTypeConverter: " + method;
058    }
059
060    @Override
061    public boolean allowNull() {
062        return allowNull;
063    }
064
065    @SuppressWarnings("unchecked")
066    public <T> T convertTo(Class<T> type, Exchange exchange, Object value) {
067        Object instance = injector.newInstance();
068        if (instance == null) {
069            throw new RuntimeCamelException("Could not instantiate an instance of: " + type.getCanonicalName());
070        }
071        // inject parent type converter
072        if (instance instanceof TypeConverterAware) {
073            if (registry instanceof TypeConverter) {
074                TypeConverter parentTypeConverter = (TypeConverter) registry;
075                ((TypeConverterAware) instance).setTypeConverter(parentTypeConverter);
076            }
077        }
078        return useExchange
079            ? (T)ObjectHelper.invokeMethod(method, instance, value, exchange) : (T)ObjectHelper
080                .invokeMethod(method, instance, value);
081    }
082
083}