i want to develop an Android application that will take the content from internet (server) and present it in the application.
(ex. i take the todays weather forecast, put the numbers in SQLite database or .txt file , put the database/txt file on internet serve开发者_运维问答r so when i open the application, the app connects&downloads the database via the net and presents me with todays forecast)
If you can references me to some example/video tutorial/book that deals with this issue i will be very thankful!
What you want to do is developing a rest api that provides data for your android app. E.g. you website has some content that you want use in your app, then you could write a php script that just returns that data in a specific format.
E.g. mysite.net/rest/fetchAllLocations.php?maybe_some_parameters
This would return locations in e.g. json format, here is an example how that looks like:
[{"id":1,"shop_lng":8.5317153930664,"shop_lat":52.024803161621,"shop_zipcode":33602,"shop_city":"Bielefeld","shop_street":"Arndtstra\u00dfe","shop_snumber":3,"shop_name":"M\u00fcller","shop_desc":"Kaufhaus"}]
Here is an example for a rest api request:
http://shoqproject.supervisionbielefeld.de/public/gateway/gateway/get-shops-by-city/city/Bielefeld
So when you have your rest api set up you can deal with receiving that data with your android phone. I use a static method to get this data:
public class JsonGrabber{
public static JSONArray receiveData(){
String url = "your url";
String result = "";
DefaultHttpClient client = new DefaultHttpClient();
HttpGet method = new HttpGet(url);
HttpResponse res = null;
try {
res = client.execute(method);
} catch (ClientProtocolException e1) {
e1.printStackTrace();
} catch (IOException e1) {
e1.printStackTrace();
}
try{
InputStream is = res.getEntity().getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"));
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
}catch(Exception e){
Log.e("log_tag", "Error converting result "+e.toString());
}
JSONArray jArray = null;
try{
jArray = new JSONArray(result);
}catch(JSONException e){
Log.e("log_tag", "Error parsing data "+e.toString());
}
return jArray;
}
}
Well thats all, once you have your data in json format you just have to parse it:
JSONArray test = (JSONArray) JsonGrabber.receiveData()
try {
for(int i=0;i<test.length();i++){
JSONObject json_data = test.getJSONObject(i);
int id = json_data.getInt("id");
}
}
The web request should run in another thread, because it can be a time consuming process. So you need to deal with AsyncTask. Here are some resources:
Painless Threading Multithreading for performance Hello Android Tutorial
精彩评论