Develop Reference

Two separate ASyncTasks wrongly combining data when processing JSON

I have a project with a TabLayout + ViewPager to scroll through two different fragments (one shows data happening currently and the other shows all data).
In the onCreateView's of both of these I call the same ASyncTask class with the only difference being the params changing.
FetchItems asyncTask = new FetchItems(getContext(), this);
asyncTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,"someParams");
The JSON result is then processed here:
try {
LinkedList<LeagueItem> leagues = new LinkedList<>();
LeagueItem newLeague;
//For every league in the array
for (int i = 0; i < jsonBody.length(); i++) {
newLeague = new LeagueItem();
//Hold the league games
JSONObject jsonLeagueInfo = jsonBody.getJSONObject(i);
newLeague.setLeagueName(jsonLeagueInfo.getString("name"));
JSONArray leagueMatches = jsonLeagueInfo.getJSONArray("matches");
//For every match in that league
for(int j = 0;j<leagueMatches.length();j++){
JSONObject matchInformation = leagueMatches.getJSONObject(j);
JSONArray teamsArray = matchInformation.getJSONArray("teams");
MatchItem currentMatch = new MatchItem();
//For both teams in the match
for(int k=0;k<2;k++){
JSONObject teamInfo = teamsArray.getJSONObject(k);
String name = teamInfo.getString("name");
String logoUrl = teamInfo.getString("logo");
JSONObject scores = teamInfo.getJSONObject("results");
String runningScore = scores.getString("runningscore");
TeamItem currentTeam = new TeamItem(shortName, logoUrl, Integer.parseInt(runningScore), homeNum);
currentMatch.addTeam(currentTeam);
}
newLeague.addMatch(currentMatch);
}
leagues.add(newLeague);
}
return leagues;
}
I'm finding that both objects returned have crossover data which shouldn't be there. Both of the parent objects are correct in that they add the correct number of league items, however every league contains pretty much all the data that I'm iterating over. Am I missing something huge here? I thought that by calling executeOnExecuter I would be getting two completely separate threads with different objects.
Thanks.

Strange results!!! Is it because of json? or what?

I have a class called GradeModel2 that has 2 members: grade (as string) and sections (as list of strings). I am trying to get my GradeModel2s data from a json string that I've read from a server.
List<GradeModel2> gradeList = new ArrayList<>();
List<String> sectionsList = new ArrayList<>();
JSONObject jo = new JSONObject(json);
JSONArray grades = jo.getJSONArray("grades");
for (int i=0;i<grades.length();i++){
sectionsList.clear();
JSONObject grade = grades.getJSONObject(i);
JSONArray sections = grade.getJSONArray("sections");
Log.e("length",sections.length()+"");
for (int k=0;k<sections.length();k++)
sectionsList.add(sections.getString(k));
gradeList.add(new GradeModel2(grade.getString("grade"), sectionsList));
}
/**************/
for (GradeModel2 grade : gradeList) {
List<String> ss = grade.getSections();
for (String s : ss)
Log.e("section",grade.getGrade()+" : "+s);
}
/**************/
The retrieved json string looks like the following:
{"id":"596","privileges":"T","grades":[{"grade":"1","sections":["A","B","C"]},{"grade":"3","sections":["A","B"]},{"grade":"7","sections":["A"]},{"grade":"9","sections":["B"]},{"grade":"10","sections":["A"]}]}
The problem is that the sections list of all GradeModel2 objects is of length 1 and value A !!!
the first Log.e, one line before the inner for loop, shows that the length of the first item of the list is 3 (A,B, and C (see the json)). However, I am trying to print all the sections of each GradeModel2 object in the inner for loop in the second block, but all I see section A for all the grades!!! (see the pic)
the result of the two Log.e
What is going on? Why is this happening?

Your problem is in sectionsList. You are trying to reuse same object, so this line of code new GradeModel2(..., sectionsList); will just add reference to the same sectionsList. And because of sectionsList.clear(); you see "A" from last json section ({"grade":"10","sections":["A"]}) To fix this, you have to create new array each time in your for loop. Something like this:
for (int i = 0 ; i < grades.length() ; i++){
List<String> sectionsList = new ArrayList<>();
// ... your json code here
gradeList.add(new GradeModel2(grade.getString("grade"), sectionsList));
}

Data not bind as it came from service in android

Data is not binding in array list as it came from the Service, as like first option which added in ArrayList is Lead, second is Qualified, and third is test. When i check list on first position it shows Qualified, Lead, test. But i want as i bind my list as it show in that sequence.
public static HashMap<String,ArrayList<LeadData>> LeadDataMap= new HashMap<String,ArrayList<LeadData>>();
public static ArrayList<String> aList = new ArrayList<String>();
for (int i = 0; i < LeadListsJSONArray.length(); i++) {
JSONObject Leadsobj = LeadListsJSONArray.getJSONObject(i);
//get stage name for hashmap key value..
String StageNameString = Leadsobj.getString("StageName");
String StageIdString = Leadsobj.getString("StageId");
System.out.println("stage id........................"+StageIdString);
//get new leads list..
JSONArray jaarr2 = new JSONArray(Leadsobj.getString("Leads"));
ArrayList<LeadData> leadDataList = new ArrayList<LeadData>();
for (int j = 0; j < jaarr2.length(); j++) {
LeadData ld = new LeadData();
JSONObject obj3 = jaarr2.getJSONObject(j);
ld.setLeadCompanyName(obj3.getString("LeadCompanyName"));
ld.setLeadId(obj3.getString("LeadId"));
ld.setTitle(obj3.getString("Title"));
leadDataList.add(ld);
}
//here we are puttin the leaddatalist inot map with respect to stage name...
LeadDataMap.put(StageNameString.trim().toString(), leadDataList);
//LeadDataMap.put(StageIdString, leadDataList);
}
In LeadDataMap data in not in that sequence in that i have put. This is the problem.

I get solution by using LinkedHashmap.

JSON data list dynamic

I am working in Android just for a heads up. I was able to retrieve JSON data but now I have come to the point where there are multiples. Example:
"workers":[
{
"id":3357,
"username":"Unreliable.worker",
"password":"x",
"monitor":0,
"count_all":41,
"count_all_archive":0,
"hashrate":477,
"difficulty":106.56
},
{
"id":4061,
"username":"Unreliable.worker2",
"password":"x",
"monitor":0,
"count_all":0,
"count_all_archive":null,
"hashrate":0,
"difficulty":0
}
would I have to do a for loop or is there another way to do it?
This is the code that I am using now to get them:
JSONObject workersJSONObject = personalJSONObject.getJSONObject("workers");
but I don't know how I would get for each and separate them. I'll get them by using:
id= workersJSONObject.getDouble("id");

[] in JSON refers to a JSON array. You could use something like:
JSONArray workersJSONArray = personalJSONObject.getJSONArray("workers");
Then loop through each item as (basically get each object inside array):
for (int i = 0; i < workersJSONArray.length(); i++) {
JSONObject workersJSONObject = workersJSONArray.getJSONObject(i);
// parse object just like before
}

On JSON, {} defines an object, [] defines an array instead. if you want details. see this and JSONArray
sample:
JSONArray workersJSOnArray = new JSONArray(stringData);
or
JSONArray workersJSOnArray = personalJSONObject.getJSONArray("workers");
/* THen you can loop from each data you want */
int len = workersJSOnArray.length();
for (int i = 0; i < len; i++)
{
JSONObject item = workersJSOnArray.optJSONObject(i);
int id = item.getInt ("id");
.....
}

Parsing JSON then adding multiple strings to an ArrayList

Currently working on an app that takes results from a search, parses the JSON object returned, and then adds the resulting pieces into a few ArrayLists within a class created called VenueList.
Here is the method that receives the results from the service and parses the JSON:
private static List<String> getResultsFromJson(String json) {
ArrayList<String> resultList = new ArrayList<String>();
try {
JSONObject resultsWrapper = (JSONObject) new JSONTokener(json).nextValue();
JSONArray results = resultsWrapper.getJSONArray("results");
for (int i = 0; i < results.length(); i++) {
JSONObject result = results.getJSONObject(i);
resultList.add(result.getString("text"));
}
}
catch (JSONException e) {
Log.e(TAG, "Failed to parse JSON.", e);
}
return resultList;
}
What results of this becomes a List variable call mResults (to clarify: mResults = getResultsFromJson(restResult);. That is then used, among other places, in the following loop that puts the results into an ArrayAdapter that is used for displaying them in a ListFragment:
for (String result : mResults) {
VenueList.addVenue(result, "HELLO WORLD");
adapter.add(result);
}
I also add the result to a class called VenueList that manages the results and makes them accessible for multiple views. It essentially just holds multiple ArrayLists that hold different types of details for each venue returned in the search. The method I use to add a venue to VenueList is below (and you can see it used in the for loop above):
public static void addVenue(String name, String geo) {
venueNames.add(name);
venueGeos.add(geo);
}
I want the addVenue method to be able to take multiple arguments and update the VenueList class. Yet, when I call the addVenue method in the for loop, I can only pass it String result (from the parameters of the loop) and can't figure out how to pass it a second argument (which should also come from the JSON parsed by getResultsFromJson) so I've used "HELLO WORLD" as a placeholder for now.
I realize getResultsFromJson only has one list returned. I need to be able to take multiple elements from the JSON object that I parse, and then add them to VenueList in the right order.
So my questions are:
1) Given the getResultsFromJson method and the for loop, how can I use the addVenue() method as designed? How do I parse multiple elements from the JSON, and then add them to the VenueList at the same time? I plan on adding more arguments to it later on, but I assume if I can make it work with two, I can make it work with four or five.
2) If that's not possible, how should the getResultsFromJson, the for loop, and the addVenue method be redesigned to work properly together?
Please let me know if you need more detail or code - happy to provide. Thank you!
EDIT - Full VenueList class:
public class VenueList {
private static ArrayList<String> venueNames;
private static ArrayList<String> venueGeos;
public VenueList() {
venueNames = new ArrayList<String>();
venueGeos = new ArrayList<String>();
}
public static void addVenue(String name, String geo) {
venueNames.add(name);
venueGeos.add(geo);
}
public static String getVenueName(int position) {
return venueNames.get(position);
}
public static String getVenueGeo(int position) {
return venueGeos.get(position);
}
public static void clearList() {
venueNames.clear();
venueGeos.clear();
}
}
Clarification: I will have additional ArrayLists for each element of data that I want to store about a venue (phone number, address, etc etc)

1) I don't think methods getResultsFromJson(String json) and addVenue(String name, String geo) fit your needs.
2) I would consider rewriting method getResultsFromJson(String json) to something like this:
private static SortedMap<Integer, List<String>> getResultsFromJson(String json) {
Map<Integer, String> resultMap = new TreeMap<Integer, String>();
//...
return resultMap;
}
where the number of keys of your map should be equal to the number of objects you're extracting info, and each one of them will properly have their own list of items just in the right order you extract them.
With this approach you can certainly change your logic to something like this:
// grab your retuned map and get an entrySet, the just iterate trough it
SortedMap<Integer, String> result = returnedMap.entrySet();
for (Entry<Integer, String> result : entrySet) {
Integer key = result.getKey(); // use it if you need it
List<String> yourDesiredItems = result.getValue(); // explicitly shown to know how to get it
VenueList.addVenue(yourDesiredItems);
}
public static void addVenue(List<String> yourDesiredItems) {
// refactor here to iterate the items trough the list and save properly
//....
}
EDIT -- as you wish to avoid the go-between map i'm assuming you need nothing to return from the method
First i'm providing you with a solution to your requirements, then i'll provide you with some tips cause i see some things that could smplify your design.
To save VenueList things directly from getResultsFromJSON do something like this:
private static void getResultsFromJson(String json) {
try {
JSONObject resultsWrapper = (JSONObject) new JSONTokener(json).nextValue();
JSONArray results = resultsWrapper.getJSONArray("results");
for (int i = 0; i < results.length(); i++) {
JSONObject result = results.getJSONObject(i);
//FOR EXAMPLE HERE IS WHERE YOU NEED TO EXTRACT INFO
String name = result.getString("name");
String geo = result.getString("geo");
// and then...
VenueList.addVenue(name, geo, ..., etc);
}
} catch (JSONException e) {
Log.e(TAG, "Failed to parse JSON.", e);
}
}
This implies that your addVenue method should know receive all params needed; as you can see this is just a way (that you can consider a workaround to your needs), however as i don't know all requirements that lead you to code this model, i will point to a few things you might consider:
1. If there's a reason for VenueList class to use everything static, consider doing this:
static{
venueNames = new ArrayList<String>();
venueGeos = new ArrayList<String>();
//....
}
private VenueList(){
}
This way you won't need to get an instance every time and also will avoid null pointer exceptions when doing VenueList.addVenue(...) without previous instantiation.
2. Instead of having an ArrayList for every characteristic in VenueList class consider defining a model object for a Venue like this:
public class Venue{
String name;
String geo;
//... etc
public Venue(){
}
// ... getters & setters
}
then if you need that VenueList class you will just have a list o Venue objects (List<Venue>), this means that instead of calling the method addVenue, you will first create a brand new instance of Venue class and will call the setter method of each characteristic, as an example of the refactored for loop from the workaround i provided you you'd be using something like this:
List<Venue> myListOfVenues = new ArrayList<Venue>();
for (int i = 0; i < results.length(); i++) {
JSONObject result = results.getJSONObject(i);
// THIS WOULD REMAIN THE SAME TO EXTRACT INFO
String name = result.getString("name");
String geo = result.getString("geo");
// and then instead of calling VenueList.addVenue(name, geo, ..., etc)...
Venue v = new Venue();
v.setName(name);
v.setGeo(geo);
// ...etc
myListOfVenues.add(v);
}
// Once you're done, set that List to VenueList class
VenueList.setVenueList(myListOfVenues);
So VenueList class would now have a single property List<Venue> venueList; and would suffer minor tweeks on methods getVenueName, etc... and everything would be more readable... i hope this helps you to get another approach to solve your problem, if i still don't make my point let me know and i'll try to help you out...