how to retrieve all images in MySQL to android
really I can retrieve data like (names,ages,....)
but really I can't retrieve all images
whereas I have a table in MySQL contain
(name , age,Image)
thanks for any guide and any help
i'm not sure this will helpful or not but you cant try this. http://www.androidbegin.com/tutorial/android-json-parse-images-and-texts-tutorial/
Probably you should consider to store the images in the local storage (instead of in a binary format, which is how it seems you are doing it, from your question), and in your database just store the file location. This way you shouldn't have problems converting the data from and to the database, and the database size wouldn't grow too much.
Then in your list view's adapter, you'll only need to retrieve the image's location and load it into the view you want to display.
EDIT
As I understood, you are sending the data to the Android device via Json. So let's assume you are sending a Json array like this one:
[{"username":"John", "userimage":"http://example.com/images/imagejohn.jpg"},
{"username":"Michael", "userimage":"http://example.com/images/imagemike.jpg"},
{"username":"Sophia", "userimage":"http://example.com/images/imagesophia.jpg"}]
So what you need is to read the JSON contents to an Array and fill it in an adapter. As I mentioned in the comments, you should take a look to the answer here: https://stackoverflow.com/a/8113337/1991053
Basically, you can read the JSON Array and put it into the ListView's Array Adapter, in the example above, you can retrieve each element like this:
JSONArray jsonArray = new JSONArray(input) // input is the JSON string you recieve
for(int i = 0; i < jsonArray.length(); i++) {
String userName = jsonArray.optJSONObject(i).getString("username");
String imageURL = jsonArray.optJSONObject(i).getString("userimage");
// Here you can do whatever you want with the values
// like loading an imageview with the url's data
// or putting the values in an ArrayList for filling up the ListView adapter
}
Of course you can modifiy this to fit in whatever the JSON structure you are using for sending the data, just use JSONObjects and JSONArray for this. Take a look to the documentation here: JSONArray, JSONObject
If you want more control over the JSON data (like serialize or deserialize the data), take a look to Jackson or Gson. There are plenty of examples around to understand how they work.
But I think your best bet is to use the adapter shown Here. Also, for loading up images in a ListView from a URL, you can use this library: Lazy List.
Hope this helps you for a start. Best regards.
Related
I have a raw json file like this
{"_id":707860,"name":"Hurzuf","country":"UA","coord":{"lon":34.283333,"lat":44.549999}}
{"_id":519188,"name":"Novinki","country":"RU","coord":{"lon":37.666668,"lat":55.683334}}
{"_id":1283378,"name":"Gorkhā","country":"NP","coord":{"lon":84.633331,"lat":28}}
{"_id":1270260,"name":"State of Haryāna","country":"IN","coord":{"lon":76,"lat":29}}
{"_id":708546,"name":"Holubynka","country":"UA","coord":{"lon":33.900002,"lat":44.599998}}
{"_id":1283710,"name":"Bāgmatī Zone","country":"NP","coord":{"lon":85.416664,"lat":28}}
{"_id":529334,"name":"Mar’ina Roshcha","country":"RU","coord":{"lon":37.611111,"lat":55.796391}}
{"_id":1269750,"name":"Republic of India","country":"IN","coord":{"lon":77,"lat":20}}
{"_id":1283240,"name":"Kathmandu","country":"NP","coord":{"lon":85.316666,"lat":27.716667}}
{"_id":703363,"name":"Laspi","country":"UA","coord":{"lon":33.733334,"lat":44.416668}}
It is NOT an JSON array - it is a huge list of JSON objects. Here Populate the spinner from JSON In Android, here Convert json array to list of json(raw) strings here android how to convert json array to string array or even here https://developer.android.com/guide/topics/ui/controls/spinner.html it is assumed that I have a JSON array or static data. I'd like to have two spinners in which one is for country and second one is for city. Let's assume I have list of countries so it will be a static data. I'd like the second spinner to dynamically load from raw json file all cities that corresponds to selected city in first spinner. I think that I can handle spinners thing but how can I load data from raw json file into spinner? Do I need to modify this raw file so that it will be a json array and then do something like this:
JSONArray jsonArray = new JSONArray(arraytitle);
List<String> list = new ArrayList<String());
for(int i = 0 ; i < jsonArray.length();i++){
list.add(jsonArray.getJSONObject(i));
}
EDIT
I found this answer https://stackoverflow.com/a/26780581/4671908 - if I will succeed I will post an answer
So you have two questions:
How to update the second Spinner dynamically when the first Spinner is updated
Three thing you need to do:
Implement AdapterView.OnItemSelectedListener
Update the backed data set inside the adapter of the second Spinner. In your case it would be a list of city. (To do this you need to create your own adapter extended from ArrayAdapter)
Call adapter.notifyDataSetChanged()
How to use the JSON
There are several solutions there. But it would be hard for others to provide the one that would suit your case the best without knowing any detail of the requirement.
Just remember one thing when you face design problem:
Do the simplest thing first.
i would like to ask, how to store json data. I have a JSON file, which i parse using JSON Library. Now i got the data from a file. But i want to store them and show them later again.
The question is, whats the best way to store data? And is it even worth to store them?
I'm thinking about sql database, because its simple and most used.
Official android docs have few examples, so far i searched but if u have better guide, let me know.
Thank you! :)
EDIT1:
Ok, i have json file with data, which i can add to my app using RAW resources. Those data wont change, its a list of recipes, i dont have to download it. I can read the data like this:
InputStream is = mContext.getResources().openRawResource(R.raw.package_01);
Writer writer = new StringWriter();
char[] buffer = new char[1024];
try {
Reader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
int n;
while ((n = reader.read(buffer)) != -1) {
writer.write(buffer, 0, n);
}
is.close();
//catchblock
.....
}
and then i can parse the data trought JSONLibrary like this:
try {
//representing []JSON
JSONArray jsonArray = new JSONArray(writer.toString());
if(jsonArray != null){...}
...}
Im sending a HashMap to ListView, which includes name and id. And if the user clicks the ListView/GridView item, there is new Activity started, which shows all parsed data. I need to get match those parsed data with the id.
There are about 200 recipes in the file. The data are parsed on start of the Activity, while Splashscreen is displayed. I´m not sure, if its good idea to parse the data everytime when app starts.
So, is it effitient to parse data everytime the app starts? And if yes, how to keep the parsed data "together"? Should i use HashMap?
I hope i clarified my question :) Thanks for help.
EDIT2:
So after i knew what to do, i tried the suggested solution to use HashMap. Problem was there i got Failed Binder Exception. I have images encoded in Base64, that means i have a very long String, example here. That is a lot of data, there is limit:
The Binder transaction buffer has a limited fixed size, currently 1Mb, which is shared by all transactions in progress for the process.
I´ve tried to save it to
Set<String> titles = new HashSet<String>();
and then to SharedPreferences but the data for each recipe gets mixed.
**So, here it comes again, should i save the data to SQLite database or is there another effective option i can use? **
Thank you!
It really depends on a number of things like: How much data do you have now, how much will you have later, how complicated is the data. You could use something as simple as an array or hashmap; or something as complex as a database. You need to consider what you are trying to do , and find the simplest solution. If you are trying to persist data, you could use shared preferences, database, and internal/external storage (options outlined here).
Without more information it's hard to say what exactly to do. Keep it simple though. If you are getting JSON from a web service, I'd use an ArrayList or HashMap to store the data, rather than persisting it. It is simpler to implement and does the job.
EDIT:
To answer your question: Yes, using a HashMap and parsing each time is fine. You only have 200 fields, and you don't have images, so the time it will take to parse is minimal. Regardless of how you store the data, there is going to some level of "parsing" done. For example, if you store the data in a database, you are going to have to still pull the data, and put it into a HashMap.
I have to submit data from 30 pages into the server.These datas from 30 pages are to be made into a single string and that i have to upload that single string into the server using json.
Each page may contain many answers tht may be either in plain text(value we receive from edit text),from check boxes(yes or no) and so on.....please suggest me a way to add all these data into a single string and upload it using json.
Based on the comment I suspect that you believe that you need to treat these "pages" as strings that you concat. However, what I think you're overlooking is that JSON is pretty versatile in how you add objects to it.
So, let's say you have the thing that you want to ship to your server and you call it
JSONObject myEntireFile = new JSONObject();
you can now add stuff to it at any time like this...
JSONObject page1 = new JSONObject();
myEntireFile.put("page1", page1);
meanwhile you can put whatever you want IN page 1 (cause that's just another serialized container).
You can keep doing this until you're ready to send it, at which time you just call
myEntireFile.toString();
which will convert your object into one long, well formatted, JSON string, that you can then open store for later use.
I am working on an app, which takes data from the user, stores the data in the database. The data is retrieved using cursor, and should be put in a string array. I am successful till the retrieving part, but how can I put the data in a string array? and is using string array the right approach here?, I mean data is being added continuously and the string array size is fixed. Not sure what to do here, please help.
Okay found a solution here http://www.anddev.org/working%5Fwith%5Fthe%5Fsqlite-database%5F-%5Fcursors-t319.html
, using ArrayList would help here.
#sam You got to use ArrayList<String> for ur requirements.u can add ur retrieved data into ArrayListby this method:
arrayList.add(<ur retrieved string>);
how to extract some criteria from this page http://www.zigwheels.com/api/zigtvApi.php?method=data&module=News§ion=News
and filter this ( content_id , thumbnail, summary , headline , image) to display them as rss feeds in my android GUI
The output from that URL looks like a JSON feed. You can easily parse JSON data in Android using the JsonObject - see this tutorial for a comprehensive example.
A better (and probably easier) solution would be to use Google Gson and extract the object that way. I've written a full (compilable) program you can use as an example here.
You are receiving a JSONArray from that page. You should create some objects from that JSONArray which will be later displayed in a ListView. For retrieving objects from that feed you could use Json or Gson as #Marvin Pinto suggested, or you could also have a look at my ObjectFactory project, which is a very simple and easy to use parser. It can simply create your objects from a json or xml feed, and you could also use it asynchronously.
After you fetch your objects, with your desired option, you can create a ListAdapter and use it to display your objects in your ListView.