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
*            is parameter in UTF-8 formator not
	 * @return
	 */
	protected static Set getParameterValues( HttpServletRequest request,
			String parameterName, boolean isUTF )
	{
		HashSet parameterValues = null;
		String ISOParameterName = ( isUTF )
				? toISOString( parameterName )
				: parameterName;
		String[] ISOParameterValues = request
				.getParameterValues( ISOParameterName );
		if ( ISOParameterValues != null )
		{
			parameterValues = new HashSet( );
			for ( int i = 0; i < ISOParameterValues.length; i++ )
			{
				parameterValues.add( toUTFString( ISOParameterValues[i] ) );
			}
		}
		return parameterValues;
	}
	/**
	 * Convert UTF-8 string into ISO-8895-1
	 * 
	 * @param s
	 *            UTF-8 string
	 * @return
	 */
	protected static String toISOString( String s )