Create JSON from a plain string using pojo

Question

I have a plain string in java as given below

Roll: 1
Name: john
Roll: 2
Name: jack
Roll: 3
Roll: 4
Name: julie

See here for roll 3 name is missing,

I want to convert above string to a json like given below,

{ "block":[ { "Roll":"1", "Name":"john" }, { "Roll":"2", "Name":"jack" }, { "Roll":"4", "Name":"julie" } ] }

how can I achieve it using java, gson and pojo.

Answer 1

here's what i suggest:

import java.util.ArrayList;
import java.util.List;
import com.google.gson.Gson;

public class Test {
    public static void main(String[] args) {
        Gson gson = new Gson();
        String s = "Roll: 1\nName: john\nRoll: 2\nName: jack\nRoll: 3\nRoll: 4\nName: julie";
        String[] values = s.split("\n");
        List<Obj> objects = new ArrayList<Obj>();
        for(int i = 0; i < values.length - 1; i++){
            Obj o = new Obj(0, null);
            if(values[i].startsWith("Roll")){
                o.Roll = Integer.parseInt(values[i].split(":")[1].trim());
                if(values[i + 1].startsWith("Name")){
                    o.Name = values[i + 1].split(":")[1];
                    i++;
                } else {
                    o.Name = null;
                }
            }
            objects.add(o);
        }
        EndResult result = new EndResult();
        result.block = new Obj[objects.size()];
        for(int i = 0; i < objects.size(); i++){
            result.block[i] = objects.get(i);
        }
        System.out.println(gson.toJson(result));
    }
}

class EndResult{
    Obj[] block;
}

class Obj{
    int Roll;
    String Name;

    Obj(int Roll, String Name){
        this.Roll = Roll;
        this.Name = Name;
    }
}