Why length fuction can not use in String?

[cyrly97]

Length function can not calculate String's length.
but in AbstractJsonProvider class can calculate String's path.
Why?

[abody2k]

I just checked it out, the length method has been overridden in some of the classes without providing implementation for String length like GsonJsonProvider.class

 @Override
    public int length(final Object obj) {
        if (isArray(obj)) {
            return toJsonArray(obj).size();
        } else if (isMap(obj)) {
            return toJsonObject(obj).entrySet().size();
        } else {
            if (obj instanceof JsonElement) {
                JsonElement element = toJsonElement(obj);
                if (element.isJsonPrimitive()) {
                    return element.toString().length();
                }
            }
        }
        throw new JsonPathException("length operation can not applied to " + (obj != null ? obj.getClass().getName()
                                                                                         : "null"));
    }

and it totally depends on which file you are using, for instance these classes does implement it supporting the String length.

• JsonOrgJsonProvider implements it providing the String length.
• JsonSmartJsonProvider (this one does not override it).
• JettisonProvider implements the String length

this is the path where you can find the other implementations for this Abstract Class

json-path\src\main\java\com\jayway\jsonpath\spi\json