Bug 156912 Proxy problems with birt-viewer.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
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;
	}
	/**
	 * Preprocess a string.
	 * 
	 * @param string
	 *            the string to process.
	 * @return a string which is not null and without excessive spaces.
	 */
	protected static String preProcess( String string )
	{
		return string == null ? "" : string.trim( ); 
	}
	/**
	 * Convert UTF-8 string into ISO-8895-1
	 * 
	 * @param s
	 *            UTF-8 string
	 * @return
	 */