Decripting by JJWT a JSON String removed quotation marks -Java

Question

My web site send a JWT (built in php) to a my app developped in Java.

The JWT contains a JSON String inside a custom field called DATI. I use the library JJWT in order to decript the string contained inside DATI field:

Claims MY_CLAIMS = Jwts.parser().setSigningKey(SECRET_KEY__Byte).parseClaimsJws(STRING_JWT).getBody(); 
ArrayList ARRAY = MY_CLAIMS .get("DATI", ArrayList.class);
String DECODED_STRING_INSIDE_DATI =String.valueOf(ARRAY);

I get the string "DECODED_STRING_INSIDE_DATI" (that is a JSON String) in the correct way, but for some reason the quotation marks (") are removed:

[{id=3, id_rivenditore=-1, id_cliente=-1, ip_address=192.168.1.6, nome=DonalDuck, note=ByBye, enabled=1}]

I tested STRING_JWT in "https://jwt.io/", and there I get correctly the quotation marks:

{
  "iss": "www.mySite.it",
  "exp": 1536913435,
  "sub": "WebApp",
  "DATI": [
    {
      "id": "3",
      "id_rivenditore": "-1",
      "id_cliente": "-1",
      "ip_address": "192.168.1.6",
      "nome": "DonalDuck",
      "note": "ByBye",
      "enabled": "1"
    }
  ]
}

I really don't know how to solve it, because I cannot read the JSON string in the right way. I use jackson library to read Json String

@benjamin c without quotation marks the conversion of the JSON String in an object (made by Jackson library) failed. Consider that if I don't use the JWT encoding, the string is sent (in clear) with the quotation marks and every works properly. When I use JWT encoding, the quotation marks disappear and it doesn't work. — Fausto70, Sep 14 '18 at 12:23
@Fausto70 so you just need to convert `DATI` back to object ? — benjamin c, Sep 14 '18 at 12:39
@benjamin c Yes, I have. I tried with some deserialize customization in Jackson (in order to convert without quoation mark), but without success — Fausto70, Sep 14 '18 at 12:56

score 1 · Accepted Answer · answered Sep 14 '18 at 12:55

This might help,

You already have ArrayList containing required claims as,

ArrayList ARRAY = MY_CLAIMS.get("DATI", ArrayList.class);

To get a JSON string of claims included in this ArrayList, try below code.

ByteArrayOutputStream out = new ByteArrayOutputStream();
ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(out, ARRAY);
byte[] data = out.toByteArray();
String str = new String(data);

str contains properly formatted JSON string (with quotation marks).

@Fausto70 and consider use java naming conventions for variable naming :) — benjamin c, Sep 14 '18 at 13:54

Decripting by JJWT a JSON String removed quotation marks -Java

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