protected Object get(JSONPath path, Object rootObject, Object currentObject) {
            if (functionExpr != null) {
                return functionExpr.eval(path, rootObject, currentObject);
            }
            return path.getPropertyValue(currentObject, propertyName, propertyNameHash);
        }
@since 1.2.51
@param json
@param path
@return
src/main/java/com/alibaba/fastjson/JSONPath.java