Bug 173582 Run servlet should not be affected by values in document.[0000]
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
{
			documentName = filePath.substring( filePath
					.lastIndexOf( fileSeparator ) + 1 );
		}
		else
		{
			documentName = filePath;
		}
		String hashCode = Integer.toHexString( filePath.hashCode( ) );
		return documentFolder + File.separator + sessionId + File.separator
				+ hashCode + File.separator + documentName;
	}
	/**
	 * Clears the report document/image files which had been created last time
	 * the server starts up.
	 */
	protected static void clearTempFiles( )
	{
		
		File file = new File( documentFolder );
		deleteDir( file );
		makeDir( documentFolder );
		
		file = new File( imageFolder );
		deleteDir( file );
		makeDir( imageFolder );
	}
	/**
	 * Deletes all files and subdirectories under dir. Returns true if all
	 * deletions were successful. If a deletion fails, the method stops