/*
 * Entity.java February 2007
 *
 * Copyright (C) 2001, Niall Gallagher <niallg@users.sf.net>
 *
 * 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.simpleframework.http.message;

import org.simpleframework.transport.Channel;

/**
 * The <code>Entity</code> object is used to represent the HTTP entity received
 * from the client. The entity contains a header and body as well as the
 * underlying <code>Channel</code> for the connection. If there is no body with
 * the entity this will provide an empty body object which provides a zero
 * length sequence of bytes.
 * 
 * @author Niall Gallagher
 */
public interface Entity {

    /**
     * This is the time in milliseconds when the request was first read from the
     * underlying channel. The time represented here represents the time
     * collection of this request began. This does not necessarily represent the
     * time the bytes arrived on the receive buffers as some data may have been
     * buffered.
     * 
     * @return this represents the time the request was ready at
     */
    long getTime();

    /**
     * This is used to acquire the body for this HTTP entity. This will return a
     * body which can be used to read the content of the message, also if the
     * request is multipart upload then all of the parts are provided as
     * <code>Part</code> objects. Each part can then be read as an individual
     * message.
     * 
     * @return the body provided by the HTTP request message
     */
    Body getBody();

    /**
     * This provides the HTTP request header for the entity. This is always
     * populated and provides the details sent by the client such as the target
     * URI and the query if specified. Also this can be used to determine the
     * method and protocol version used.
     * 
     * @return the header provided by the HTTP request message
     */
    Header getHeader();

    /**
     * This provides the connected channel for the client. This is used to send
     * and receive bytes to and from an transport layer. Each channel provided
     * with an entity contains an attribute map which contains information about
     * the connection.
     * 
     * @return the connected channel for this HTTP entity
     */
    Channel getChannel();
}