Creating array list of java objects from JSON URL with Gson

Question

I am able to parse the following data into a java object:

{
    "name": "testname",
    "address": "1337 455 ftw",
    "type": "sometype",
    "notes": "cheers mate"
}

using this code:

public class Test 
{
    public static void main (String[] args) throws Exception
    {
        URL objectGet = new URL("http://10.0.0.4/file.json");

        URLConnection yc = objectGet.openConnection();
        BufferedReader in = new BufferedReader(
                new InputStreamReader(
                yc.getInputStream()));

        Gson gson = new Gson();

        try {
            DataO data = new Gson().fromJson(in, DataO.class);

            System.out.println(data.getName());
        }catch (Exception e) {
            e.printStackTrace();
        }
    }      
}

But now I want to store a list of these objects out of the following JSON String:

[
    {
        "name": "testname",
        "address": "1337 455 ftw",
        "type": "sometype",
        "notes": "cheers mate"
    },
    {
        "name": "SumYumStuff",
        "address": "no need",
        "type": "clunkdroid",
        "notes": "Very inefficient but high specs so no problem."
    }
]

Could someone help me modify my code to do this?

Solution

You could specify the type to deserialize into as an array or as a collection.

As Array:

import java.io.FileReader;

import com.google.gson.Gson;

public class GsonFoo
{
  public static void main(String[] args) throws Exception
  {
    Data0[] data = new Gson().fromJson(new FileReader("input.json"), Data0[].class);
    System.out.println(new Gson().toJson(data));
  }
}

class Data0
{
  String name;
  String address;
  String type;
  String notes;
}

As List:

import java.io.FileReader;
import java.util.List;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

public class GsonFoo
{
  public static void main(String[] args) throws Exception
  {
    List<Data0> data = new Gson().fromJson(new FileReader("input.json"), new TypeToken<List<Data0>>(){}.getType());
    System.out.println(new Gson().toJson(data));
  }
}