/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* Copyright (c) 2006 - 2013 Pentaho Corporation and Contributors. All rights reserved.
*/
package org.pentaho.reporting.libraries.resourceloader;
import java.io.InputStream;
/**
* A resource data object encapsulates the raw data of an resource at a given point in the past.
* <p/>
* Any change to the resource increases the version number. Version numbers are not needed to be checked regulary, but
* must be checked on each call to 'getVersion()'.
* <p/>
* This definitly does *not* solve the problem of concurrent modifications; if you need to be sure that the resource has
* not been altered between the last call to 'getVersion' and 'getResource..' external locking mechanism have to be
* implemented.
*
* @author Thomas Morgner
*/
public interface ResourceData {
public static final String CONTENT_LENGTH = "content-length";
public static final String CONTENT_TYPE = "content-type";
public static final String FILENAME = "filename";
public InputStream getResourceAsStream( ResourceManager caller ) throws ResourceLoadingException;
/**
* This is dangerous, especially if the resource is large.
*
* @param caller
* @return
* @throws ResourceLoadingException
*/
public byte[] getResource( ResourceManager caller ) throws ResourceLoadingException;
/**
* Tries to read data into the given byte-array.
*
* @param caller
* @param target
* @param offset
* @param length
* @return the number of bytes read or -1 if no more data can be read.
* @throws ResourceLoadingException
*/
public int getResource( ResourceManager caller, byte[] target, long offset, int length )
throws ResourceLoadingException;
public long getLength();
public Object getAttribute( String key );
public ResourceKey getKey();
public long getVersion( ResourceManager caller ) throws ResourceLoadingException;
}