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
public static final String ATTR_APPCONTEXT_VALUE = "AppContextValue"; 
	/**
	 * The initialized properties map
	 */
	public static Map initProps;
	/**
	 * viewer properties
	 */
	public static final String PROP_BASE_URL = "base_url"; 
	/**
	 * Get bookmark. If page exists, ignore bookmark.
	 * 
	 * @param request
	 * @return the bookemark
	 */
	public static String getBookmark( HttpServletRequest request )
	{
		int page = getParameterAsInt( request, PARAM_PAGE );
		return page < 1
				? getReportParameter( request, PARAM_BOOKMARK, null )
				: null;
	}
	/**
	 * Get query string with new parameter value.
	 * 
	 * @param request
	 *            http request
	 * @param name
	 *            parameter name
	 * @param value