import org.json.*;
import java.util.*;

class Response1 {
    public int page;
    public List<String> fruits;

    public Response1(int page, List<String> fruits) {
        this.page = page;
        this.fruits = fruits;
    }
}

class Response2 {
    private int page;
    private List<String> fruits;

    public Response2(int page, List<String> fruits) {
        this.page = page;
        this.fruits = fruits;
    }

    // Getters and setters
    public int getPage() { return page; }
    public void setPage(int page) { this.page = page; }
    public List<String> getFruits() { return fruits; }
    public void setFruits(List<String> fruits) { this.fruits = fruits; }
}

public class JsonExample {
    public static void main(String[] args) {
        // First, we'll look at encoding basic data types to JSON strings.
        // Here are some examples for atomic values.
        System.out.println(new JSONObject().put("value", true));
        System.out.println(new JSONObject().put("value", 1));
        System.out.println(new JSONObject().put("value", 2.34));
        System.out.println(new JSONObject().put("value", "gopher"));

        // And here are some for slices and maps, which encode
        // to JSON arrays and objects as you'd expect.
        List<String> slcD = Arrays.asList("apple", "peach", "pear");
        System.out.println(new JSONArray(slcD));

        Map<String, Integer> mapD = new HashMap<>();
        mapD.put("apple", 5);
        mapD.put("lettuce", 7);
        System.out.println(new JSONObject(mapD));

        // The JSON package can automatically encode your
        // custom data types. It will only include public
        // fields in the encoded output and will by default
        // use those names as the JSON keys.
        Response1 res1D = new Response1(1, Arrays.asList("apple", "peach", "pear"));
        System.out.println(new JSONObject(res1D));

        // You can use annotations on class field declarations
        // to customize the encoded JSON key names. Check the
        // Jackson or Gson libraries for examples of such annotations.
        Response2 res2D = new Response2(1, Arrays.asList("apple", "peach", "pear"));
        System.out.println(new JSONObject(res2D));

        // Now let's look at decoding JSON data into Java
        // values. Here's an example for a generic data
        // structure.
        String jsonStr = "{\"num\":6.13,\"strs\":[\"a\",\"b\"]}";
        JSONObject jsonObj = new JSONObject(jsonStr);

        // We can access values in the decoded object directly.
        double num = jsonObj.getDouble("num");
        System.out.println(num);

        // Accessing nested data is straightforward.
        JSONArray strs = jsonObj.getJSONArray("strs");
        String str1 = strs.getString(0);
        System.out.println(str1);

        // We can also decode JSON into custom data types.
        // This has the advantages of adding additional
        // type-safety to our programs.
        String str = "{\"page\": 1, \"fruits\": [\"apple\", \"peach\"]}";
        JSONObject obj = new JSONObject(str);
        Response2 res = new Response2(obj.getInt("page"), 
                                      Arrays.asList(obj.getJSONArray("fruits").getString(0),
                                                    obj.getJSONArray("fruits").getString(1)));
        System.out.println(res.getPage());
        System.out.println(res.getFruits().get(0));

        // In Java, we can directly write JSON to output streams.
        JSONObject d = new JSONObject();
        d.put("apple", 5);
        d.put("lettuce", 7);
        System.out.println(d.toString());
    }
}