Bug 176681 Issue about creating context-parameter path in read-only path[0601]
Description: Issue about creating context-parameter path in read-only path Build number:2.2.0.v20070308 Steps to reproduce: 1. Deploy birt. 2. Set BIRT_VIEWER_DOCUMENT_FOLDER/BIRT_VIEWER_IMAGE_DIR/.. to a read-only path. 3. Preview report. Expected result: Because the path is read-only, folders should be created in ${java.io.tmpdir} Actual result: No folders are created in ${java.io.tmpdir} and reports cannot be previewed in frameset mode.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
{
		String fileName = getReport( request, null );
		if ( fileName.indexOf( '.' ) >= 0 )
		{
			fileName = fileName.substring( 0, fileName.lastIndexOf( '.' ) );
		}
		
		String id = getParameter( request, PARAM_ID );
		if ( id != null && id.length( ) > 0 )
		{
			fileName = fileName + id + SUFFIX_REPORT_DOCUMENT;
		}
		else
		{
			fileName = fileName + SUFFIX_REPORT_DOCUMENT;
		}
		return fileName;
	}
	/**
	 * Get named parameter from http request. parameter names and values are all
	 * in iso-8859-1 format in request.
	 * 
	 * @param request
	 *            incoming http request
	 * @param parameterName
	 *            parameter name in UTF-8 format
	 * @return
	 */
	public static String getParameter( HttpServletRequest request,
			String parameterName )