Java JSON reading from URL

Question

I'm trying to use my weather API to get the weather condition for an area, I think I have everything functioning except for the data parsing part.

import java.net.*;
import java.io.*;
import com.google.gson.*;

public class URLReader {

    public static URL link;

    public static void main(String[] args) {
        try{
            open();
            read();
        }catch(IOException e){}
    }

    public static void open(){
        try{
            link = new URL("http://api.wunderground.com/api/54f05b23fd8fd4b0/geolookup/conditions/forecast/q/US/CO/Denver.json");
        }catch(MalformedURLException e){}
    }
    public static void read() throws IOException{
        //little bit stuck here
    }
}

Can anyone help me to finish this simple little project, I'm a beginner btw.

possible duplicate of [Parsing JSON Object in Java](http://stackoverflow.com/questions/5015844/parsing-json-object-in-java) — Eel Lee, Nov 13 '13 at 14:33
gson java library would be more than enough. here's the URL: http://code.google.com/p/google-gson/ — Olimpiu POP, Nov 13 '13 at 14:33
I should have specified, I'm already using the gson library. — Arc, Nov 13 '13 at 14:36

score 1 · Accepted Answer · edited Nov 13 '13 at 15:05

You can use javaQuery to do this more easily:

$.getJSON("http://api.wunderground.com/api/54f05b23fd8fd4b0/geolookup/conditions/forecast/q/US/CO/Denver.json", null, new Function() {
    @Override
    public void invoke($ j, Object... args) {
        //if you are expecting a JSONObject, use:
        JSONObject json = (JSONObject) args[0];

        //otherwise, it would be: JSONArray json = (JSONArray) args[0];

        //Then to more easily parse the JSON, do this:
        Map<String, ?> map = $.map(json)

        //if you are using an array instead, you can use: Object[] array = $.makeArray(json);

        //Now just iterate through your map (or list) to get the data you want to parse.
    }
});

score 1 · Answer 2 · answered Nov 13 '13 at 14:55

Just open connection from URL and try to read JSON from it:

public static void read() throws IOException{
    InputStream is = null;
    try {
        is = link.openConnection().getInputStream();

        Reader reader = new InputStreamReader(is);

        Map<String, String> jsonObj = gson.fromString(reader, new TypeToken<Map<String, String>>() {}.getType());

        //TODO do next stuff
    } finally{
        if (is != null){
            is.close();
        }
    }
}

If you want, you can bind jsonObj into whatever you want, please read documentation.

Java JSON reading from URL

2 Answers2