如何编辑/写回json文件？

Question

below is my java code to read from a json file

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Iterator;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;



public class FileIO {

    @SuppressWarnings("unchecked")
    //public static Showtime [] movie = MoviesListing.movie();

    public void importTxt() {
        int j = 0;
        JSONParser parser = new JSONParser();

        try {
            JSONArray a = (JSONArray) parser.parse(new FileReader("C:/Users/Glambert/Dropbox/java/New folder/perfection/UPdate/json.txt"));

            for (Object o : a)
            {
                JSONObject person = (JSONObject) o;

                MoviesListing.movie[j].assign((String) person.get("moviename"));
                MoviesListing.movie[j].assignShowingStatus((String) person.get("showingstatus"));
                MoviesListing.movie[j].assignSynopsis((String) person.get("synopsis"));
                MoviesListing.movie[j].assignDirector((String) person.get("director"));
                MoviesListing.movie[j].assignCast((String) person.get("cast"));
                MoviesListing.movie[j].assignReviewerRate((double) person.get("reviewerRate"));
                MoviesListing.movie[j].assignPastReviews((String) person.get("pastreviews"));
                MoviesListing.movie[j].assignMovieRating((String) person.get("movierating"));
                MoviesListing.movie[j].assignShowtimes((JSONArray) person.get("showtimes"));

                j++;
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        }
    }

It works from reading a json file like this:

[  
  {  
    "moviename":"Goosebumps",
    "showingstatus":"Now Showing",
    "synopsis":"Upset...",
    "director":"Rob Letterman",
    "cast":"Jack Black, Dylan Minnette, Odeya Rush, Amy Ryan",
    "reviewerRate": 3.2 ,
    "pastreviews":"Goosebumps...",
    "movierating":"PG",
    "showtimes":[  
        "09.30",
        "12.30"
    ],
    "job":"Teacher"
  },
  {  
    "moviename":"Bridge of Spies",
    "showingstatus":"Now Showing",
    "synopsis":"Tom Hanks stars..",
    "director":"Steven Spielberg",
    "cast":"Tom Hanks, Mark Rylance",
    "reviewerRate": 3.9,
    "pastreviews":"JBridge...",
    "movierating":"PG-13",
    "showtimes":[  
        "09.40",
        "10.45"
    ],
  }
]

However, I want to write/edit into the txt file in the same, or at least close to this format. Anyone knows how to do that?

Answer 1

In the JSON format you have provided, remove the comma after last array:

....
"showtimes":[  
    "09.40",
    "10.45"
    ]
  }
]

Solution: You can use (Download the Jar file from Maven) http://mvnrepository.com/artifact/com.google.code.gson/gson

And Create a Bean for Your Data as below:

MovieBean.java
private String moviename;
private String showingstatus;
...
private ArrayList<Double> showtimes;
private String job;

And After that you can use, Gson methods fromJson and toJson for creating JSON to Bean and Bean to JSON respectively. You can edit the data in Bean and save it again on the same content file.