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/*
* 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 - 2009 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.
*
* 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()'.
*
* 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;
}
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