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.component.extension;
018
019import java.util.Map;
020import java.util.Optional;
021
022import org.apache.camel.Exchange;
023import org.apache.camel.TypeConversionException;
024
025public interface MetaDataExtension extends ComponentExtension {
026    /**
027     * @param parameters
028     * @return the {@link MetaData}
029     */
030    Optional<MetaData> meta(Map<String, Object> parameters);
031
032    interface MetaData {
033        // Common meta-data attributes
034        String CONTENT_TYPE = Exchange.CONTENT_TYPE;
035        String JAVA_TYPE = "Java-Type";
036        String CONTEXT = "Meta-Context";
037
038        /**
039         * Returns an attribute associated with this meta data by name.
040         *
041         * @param name the attribute name
042         * @return the attribute
043         */
044        Object getAttribute(String name);
045
046        /**
047         * @return a read-only list of attributes.
048         */
049        Map<String, Object> getAttributes();
050
051        /**
052         *
053         * Returns an attribute associated with this meta data by name and
054         * specifying the type required.
055         *
056         * @param name the attribute name
057         * @param type the type of the attribute
058         * @return the value of the given attribute or <tt>null</tt> if there is no attribute for the given name
059         * @throws TypeConversionException is thrown if error during type conversion
060         */
061        <T> T getAttribute(String name, Class<T> type);
062
063        /**
064         * Returns the payload of the meta data as a POJO.
065         *
066         * @return the body, can be <tt>null</tt>
067         */
068        Object getPayload();
069
070        /**
071         * Returns the payload of the meta data as specified type.
072         *
073         * @param type the type that the payload should be converted yo.
074         * @return the payload of the meta data as the specified type.
075         * @throws TypeConversionException is thrown if error during type conversion
076         */
077        <T> T getPayload(Class<T> type);
078    }
079}