protected void init() {
        if (segments != null) {
            return;
        }

        if ("*".equals(path)) {
            this.segments = new Segment[] { WildCardSegment.instance };
        } else {
            JSONPathParser parser = new JSONPathParser(path);
            this.segments = parser.explain();
            this.hasRefSegment = parser.hasRefSegment;
        }
    }
@author wenshao[szujobs@hotmail.com]
@since 1.2.0
src/main/java/com/alibaba/fastjson/JSONPath.java