private static DataExperssion resolveCompareExperssion(String filterExperssion) {
        DataExperssion result = null;
        String experssion = filterExperssion.trim();
        String name;
        String oper;
        String value;
        int start = 0;
        for (int i = 0; i < opers.length; i++) {
            if ((start = experssion.indexOf(opers[i])) > 0) {
                name = experssion.substring(0, start).trim();
                oper = experssion.substring(start, start + opers[i].length()).trim();
                value = experssion.substring(start + opers[i].length()).trim();
                if (name.indexOf(" ") < 0 && value.indexOf(" ") < 0) {
                    result = new CompareDataExperssion(name, oper, value);
                } else {
                    start = 0;
                }
                break;
            }
        }
        if (start <= 0) {
            result = NullDataExperssion.getInstance();
        }
        return result;
    }