Exception casting valid JSON with Java -

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i have json string:

{     "_id": -1,     "create_date": 0,     "update_date": 0,     "description": "test",     "active": true }

in java, try parse using org.json.simple.parser.jsonparser :

jsonparser jsonparser = new jsonparser(); org.json.simple.jsonobject jsonobject = (org.json.simple.jsonobject) jsonparser.parse(phonejson);

i try retrieve _id field value:

string s_id = ((string) jsonobject.get("_id"));

but encounter following exception:

java.lang.long cannot cast java.lang.string

furthermore, if display field value in console:

system.out.println("print value -  _id: "+jsonobject.get("_id"));

i get:

print value -  _id: -1

output in console.

i have seen post:

java.lang.long cannot cast java.lang.string

but not me.

what not understanding?

you have use .tostring() method convert long string.

string strlong = long.tostring(jsonobject.get("_id")));

reference:

returns string object representing long's value.

also, reason println outputs value in console because printstream.println has overload takes object, , calls tostring method.


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