Write JSON object in a file

import java.io.FileWriter;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;

try{
  JSONObject myJsonObject = new JSONObject(); 
  FileWriter file = new FileWriter("/path/to/file/to/write.json");
  myJsonObject.put("key", "value");
  file.write(myJsonObject.toJSONString()); 
  file.flush();
} catch (IOException e) {
  e.printStackTrace();
}