• After 15+ years, we've made a big change: Android Forums is now Early Bird Club. Learn more here.

json parsing

L

larryse

Lurker
i am creating a snipet of code for an app that takes a json string and returns an ArrayList. i did one verson with gson and an trying to do it using straight json. but when running the json part i keep getting cant find local variable 'feedArray'\ it only happen for the jsonToFeedItem method
my code is

Code: 
package ca.sbmgroup.codechallengelarryseymour;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import com.google.gson.Gson;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    [USER=1021285]@override[/USER]
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String json = "[" +
                "{" +
                "'Id':1," +
                "'username':'test user'," +
                "'body':[" +
                "{" +
                "'Id':3," +
                "'bodyType':'text'," +
                "'text':'Hello World'" +
                "}," +
                "{" +
                "'Id':4," +
                "'bodyType':'image'," +
                "'mediaLocation':'http://.../'" +
                "}" +
                "]" +
                "}," +
                "{" +
                "'Id':2," +
                "'username':'test user'," +
                "'body':[" +
                "{" +
                "'Id':4," +
                "'bodyType':'video'," +
                "'mediaLocation':'http://.../'" +
                "}" +
                "]" +
                "}" +
                "]";
        //gsonToFeedItem(json);

        jsonToFeedItem(json);
    }

    public String getFeed(){
        return "...";//returns a json array of json objects representing the feed items.
    }

    public void displayFeed(ArrayList<FeedObject> feed)
    {

    }
        public ArrayList<FeedObject> gsonToFeedItem(String jsonString){
            ArrayList<FeedObject> feedList = new ArrayList<>();

            FeedObject[] feedArray = new Gson().fromJson(jsonString, FeedObject[].class);
            feedList = new ArrayList<FeedObject>(Arrays.asList(feedArray));


            return feedList;
        }

    public ArrayList<FeedObject> jsonToFeedItem(String jsonString){
        try {
        ArrayList<FeedObject> feedList = new ArrayList<>();
            JSONArray jsonArray = new JSONArray(jsonString);

            for (int i =0; i< jsonArray.length();i++)
            {
                List<body> bodyList = new ArrayList<>();
                JSONObject feedJsonObject = jsonArray.getJSONObject(i);
                int feedId = feedJsonObject.getInt("Id");
                String userName = feedJsonObject.getString("username");

                FeedObject feedObject = new FeedObject(feedId,userName);

                JSONArray bodyArray = feedJsonObject.getJSONArray("body");
                for(int r =0; r< bodyArray.length(); r++)
                {
                    body bodyObject = null;
                    JSONObject bodyJsonObject = bodyArray.getJSONObject(r);
                    int bodyId = bodyJsonObject.getInt("id");
                    String bodyType = bodyJsonObject.getString("bodyType");
                    String text = null;
                    URL mediaLocation = null;

                    if(bodyType.equals("text")){
                        text = bodyJsonObject.getString("text");
                        bodyObject = new body(bodyId, bodyType,text);
                    }
                    else {
                        mediaLocation = new URL(bodyJsonObject.getString("mediaLocation"));
                        bodyObject = new body(bodyId, bodyType, mediaLocation);
                    }
                    bodyList.add(bodyObject);
                }
                feedObject.setBodyList(bodyList);
                feedList.add(feedObject);
            }
        return feedList;
        } catch (JSONException e) {
            e.printStackTrace();
        } catch (MalformedURLException me) {
            me.printStackTrace();
        }

        return null;
    }
}

any ideas,
thanks
 
Last edited by a moderator:
larryse said:
i am creating a snipet of code for an app that takes a json string and returns an ArrayList. i did one verson with gson and an trying to do it using straight json. but when running the json part i keep getting cant find local variable 'feedArray'\ it only happen for the jsonToFeedItem method
my code is

Code: 
package ca.sbmgroup.codechallengelarryseymour;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import com.google.gson.Gson;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    [USER=1021285]@override[/USER]
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String json = "[" +
                "{" +
                "'Id':1," +
                "'username':'test user'," +
                "'body':[" +
                "{" +
                "'Id':3," +
                "'bodyType':'text'," +
                "'text':'Hello World'" +
                "}," +
                "{" +
                "'Id':4," +
                "'bodyType':'image'," +
                "'mediaLocation':'http://.../'" +
                "}" +
                "]" +
                "}," +
                "{" +
                "'Id':2," +
                "'username':'test user'," +
                "'body':[" +
                "{" +
                "'Id':4," +
                "'bodyType':'video'," +
                "'mediaLocation':'http://.../'" +
                "}" +
                "]" +
                "}" +
                "]";
        //gsonToFeedItem(json);

        jsonToFeedItem(json);
    }

    public String getFeed(){
        return "...";//returns a json array of json objects representing the feed items.
    }

    public void displayFeed(ArrayList<FeedObject> feed)
    {

    }
        public ArrayList<FeedObject> gsonToFeedItem(String jsonString){
            ArrayList<FeedObject> feedList = new ArrayList<>();

            FeedObject[] feedArray = new Gson().fromJson(jsonString, FeedObject[].class);
            feedList = new ArrayList<FeedObject>(Arrays.asList(feedArray));


            return feedList;
        }

    public ArrayList<FeedObject> jsonToFeedItem(String jsonString){
        try {
        ArrayList<FeedObject> feedList = new ArrayList<>();
            JSONArray jsonArray = new JSONArray(jsonString);

            for (int i =0; i< jsonArray.length();i++)
            {
                List<body> bodyList = new ArrayList<>();
                JSONObject feedJsonObject = jsonArray.getJSONObject(i);
                int feedId = feedJsonObject.getInt("Id");
                String userName = feedJsonObject.getString("username");

                FeedObject feedObject = new FeedObject(feedId,userName);

                JSONArray bodyArray = feedJsonObject.getJSONArray("body");
                for(int r =0; r< bodyArray.length(); r++)
                {
                    body bodyObject = null;
                    JSONObject bodyJsonObject = bodyArray.getJSONObject(r);
                    int bodyId = bodyJsonObject.getInt("id");
                    String bodyType = bodyJsonObject.getString("bodyType");
                    String text = null;
                    URL mediaLocation = null;

                    if(bodyType.equals("text")){
                        text = bodyJsonObject.getString("text");
                        bodyObject = new body(bodyId, bodyType,text);
                    }
                    else {
                        mediaLocation = new URL(bodyJsonObject.getString("mediaLocation"));
                        bodyObject = new body(bodyId, bodyType, mediaLocation);
                    }
                    bodyList.add(bodyObject);
                }
                feedObject.setBodyList(bodyList);
                feedList.add(feedObject);
            }
        return feedList;
        } catch (JSONException e) {
            e.printStackTrace();
        } catch (MalformedURLException me) {
            me.printStackTrace();
        }

        return null;
    }
}

any ideas,
thanks
Click to expand...

With my tiny bit of technology I can't cobble any application that will succeed in that task unless you're running it strictly from a closed source desk or laptop operation.
 
The reported error doesn't make much sense. Can the OP please include the Logcat output if this is a runtime problem?
 
You must log in or register to reply here.
Back
Top Bottom