How to parse JSON Format

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
        public class JSONDemo {
              public static JSONObject readJSON(){
                  JSONParser jsonParser = new JSONParser();
                  JSONObject departmentList = null;
                    try {
                   FileReader fread= new FileReader("/eclipse-workspace/JSONDemo/src/department.json");
                        Object obj = jsonParser.parse(fread);
                        departmentList = (JSONObject) obj;
                       // System.out.println(departmentList);
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    } catch (ParseException e) {
                        e.printStackTrace();
                    }
                    return departmentList;
                }
                public static void main(String[] args) {
                    System.out.println(JSONDemo.readJSON());;
                }
            }

{
       "department":{
        "deptName":"ComputerScience",
        "deptId":"101"
     },
     "subjects":{
        "cs01":"C programming",
        "cs02":"Java",
        "cs03":"BigData",
        "cs04":"datastructures and algorithms",
        "cs05":"compiler design",
        "cs06":"software design"
     }
    }