root/kraken-filter/src/main/java/org/krakenapps/filter/Message.java @ 306

/*
 * Copyright 2009 NCHOVY
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.krakenapps.filter;

import java.util.Set;

/**
 * Represents the communication unit of filter. Composed of header and
 * properties. Message is immutable.
 * 
 * @author xeraph
 * @since 1.0.0
 */
public interface Message {
        /**
         * Returns the message specification.
         */
        public MessageSpec getMessageSpec();

        /**
         * Returns a Set of property keys.
         */
        public Set<String> keySet();

        /**
         * Checks if specific key is contained.
         * 
         * @param key
         *            the name of property
         * @return true if key exists.
         */
        public boolean containsKey(String key);

        /**
         * Returns the value of the property
         * 
         * @param key
         *            the name of property
         * @returns the value of the property. null if not exists.
         */
        public Object get(String key);

        /**
         * Returns a Set of header keys.
         */
        public Set<String> headerKeySet();

        /**
         * Checks if specific header is contained.
         * 
         * @param key
         *            the name of header
         * @return true if header key exists
         */
        public boolean containsHeader(String key);

        /**
         * Returns the value of the header.
         * 
         * @param key
         *            the name of header
         * @return the value of the header. null if not exists.
         */
        public Object getHeader(String key);
}