Question: I have checked out many pages but most of the tutorials and script return an error code with this type of JSON output. So how would I be able to extract the data from this JSON in Java?:

```
[
  {
    "user":{"id":"1","username":"user1"},
    "item_name":"item1",
    "custom_field":"custom1"
  },
  {
    "user":{"id":"2","username":"user2"},
    "item_name":"item2",
    "custom_field":"custom2"
  },
  {
    "user":{"id":"3","username":"user3"},
    "item_name":"item3",
    "custom_field":"custom3"
  }
]

```

Answer: 
If you want to use Gson, then first you declare classes for holding each element and sub elements:

```
public class MyUser {
  public String id;
  public String username;
}

public class MyElement {
  public MyUser user;
  public String item_name;
  public String custom_field;
}

```

Then you declare an array of the outermost element (because in your case the JSON object is a JSON array), and assign it:

```
MyElement[] data = gson.fromJson (myJSONString, MyElement[].class);

```

Then you simply access the elements of `data`.

The important thing to remember is that the names and types of the attributes you declare should match the ones in the JSON string. e.g. "id", "item\_name" etc.
You could try JSON Simple  

<http://code.google.com/p/json-simple/>

Example:

```
JSONParser jsonParser = new JSONParser();
JSONArray jsonArray = (JSONArray) jsonParser.parse(jsonDataString);

for (int i = 0; i < jsonArray.size(); i++) {
    JSONObject obj = (JSONObject) jsonArray.get(i);
    //Access data with obj.get("item_name")
}

```

Just be careful to check for nulls/be careful with casting and such.