/**********************************************************************************
 * $URL$
 * $Id$
 ***********************************************************************************
 *
 * Copyright (c) 2003, 2004, 2005, 2006, 2008 Sakai Foundation
 *
 * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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.sakaiproject.content.api;

import java.io.InputStream;

import org.sakaiproject.exception.ServerOverloadException;

/**
* <p>ContentResource is the core interface for a Resource object in the ContentHostingService.</p>
*/
public interface ContentResource
	extends ContentEntity
{
	/**
	* Access the content byte length.
	* @return The content byte length.
	*/
	public long getContentLength();

	/**
	* Access the resource MIME type.
	* @return The resource MIME type.
	*/
	public String getContentType();

	/**
	* Access the resource sha256 checksum
	* @return The resource sha256 checksum
	*/
	public String getContentSha256();

	/**
	* Access an array of the bytes of the resource.
	* @return An array containing the bytes of the resource's content.
	* @exception ServerOverloadException
	* 			if server is configured to save resource body in filesystem and an error occurs while 
	* 			trying to access the filesystem.
	*/
	public byte[] getContent() throws ServerOverloadException;

	/**
	 * Access the content as a stream.
	 * Please close the stream when done as it may be holding valuable system resources.
	 * @return an InputStream through which the bytes of the resource can be read.
	 * @throws ServerOverloadException if the server cannot produce the content stream at this time.
	 */
	public InputStream streamContent() throws ServerOverloadException;
	
}	// ContentResource



