How to deserilize nested array json with only value using Gson?

What you have in players is a Map represented as JSON arrays.

It's an ugly map, but it's still a Map. The key is List<String> (IP and Port) with the value being a String (the "id")

It's almost like whomever wrote the server made a mistake and did it backwards especially given your description of what this is supposed to be. It really should look like:

["id_1",[["192.168.1.0","8888"], [another ip/port], ... ]

for each entry. That would make more sense, with the (String) "id" being the key and List<List<String>> as the value.

That's still ugly as they really should be using object to represent IP/Port. Ideally you would want:

["id_1",[{"ip":"192.168.1.1", "port":"8888"},{ "ip":"192.168.1.2","port":"8889"}]]

Below demonstrates how it's currently written:

public static void main( String[] args ){    String json = "{\"players\":[[[\"192.168.1.0\",\"8888\"],\"id_1\"],[[\"192.168.1.1\",\"9999\"],\"id_2\"]],\"result\":\"ok\"}";    Gson gson = new GsonBuilder().create();    MyClass c = gson.fromJson(json, MyClass.class);    c.listPlayers();}class MyClass {    public String result;    public Map<List<String>, String> players;    public void listPlayers()    {        for (Map.Entry<List<String>, String> e : players.entrySet())        {            System.out.println(e.getValue());            for (String s : e.getKey())            {                System.out.println(s);            }        }    }}

Output:

id_1
192.168.1.0
8888

id_2
192.168.1.1
9999

You can get a bit creative and make the key to the map a little more usable with:

class IpAndPort extends ArrayList<String> {    public String getIp() {        return this.get(0);    }    public String getPort() {        return this.get(1);    }}

then change:

public Map<List<String>, String> players;

to:

public Map<IpAndPort, String> players;

in MyClass