Main.java

public class Main {
    static String jsonString = "{\n" +
            "\t\"1002001\": {\n" +
            "\t\t\"level\": 2,\n" +
            "\t\t\"name\": \"CaptKrunch\",\n" +
            "\t\t\"uid\": 1002001,\n" +
            "\t\t\"user\": {\n" +
            "\t\t\t\"age\": 21,\n" +
            "\t\t\t\"chat_color\": \"CC3299\",\n" +
            "\t\t\t\"city\": \"None\",\n" +
            "\t\t\t\"country\": \"United States\",\n" +
            "\t\t\t\"creation\": 1269969663\n" +
            "\t\t},\n" +
            "\t\t\"meta\": {\n" +
            "\t\t\t\"score\": 1762.000,\n" +
            "\t\t\t\"flags\": 6176,\n" +
            "\t\t\t\"kbit\": 0,\n" +
            "\t\t\t\"lastnews\": 1459736973,\n" +
            "\t\t\t\"rank\": 78\n" +
            "\t\t}\n" +
            "\t},\n" +
            "\t\"1003001\": {\n" +
            "\t\t\"level\": 11,\n" +
            "\t\t\"name\": \"LtRaine\",\n" +
            "\t\t\"uid\": 1003001,\n" +
            "\t\t\"user\": {\n" +
            "\t\t\t\"age\": 35,\n" +
            "\t\t\t\"chat_color\": \"FFAABB\",\n" +
            "\t\t\t\"city\": \"LA\",\n" +
            "\t\t\t\"country\": \"United States\",\n" +
            "\t\t\t\"creation\": 1269369663\n" +
            "\t\t},\n" +
            "\t\t\"meta\": {\n" +
            "\t\t\t\"score\": 11562.000,\n" +
            "\t\t\t\"flags\": 1176,\n" +
            "\t\t\t\"kbit\": 2048,\n" +
            "\t\t\t\"lastnews\": 1279736973,\n" +
            "\t\t\t\"rank\": 11\n" +
            "\t\t}\n" +
            "\t}\n" +
            "}";

    public static void main(String[] args) {
        Type type = new TypeToken<Map<String, YourPOJO>>() {
        }.getType();
        Map<String, YourPOJO> map = new Gson().fromJson(jsonString, type);
        System.out.println(map);

        YourPOJO first = map.get("1002001");
        System.out.println(first.getName());
        System.out.println(first.getUser().getAge());
    }
}

User.java

public class User {
    private int age;

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

YourPOJO.java

public class YourPOJO {
    private String name;
    private int level;
    private User user;

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getLevel() {
        return level;
    }

    public void setLevel(int level) {
        this.level = level;
    }
}