Android GET And POST Request

January 26, 2023 Post a Comment

Can anyone point me to a good implementation of a way to send GET and POST Requests. They are alot of ways to do these, and i am looking for the best implementation. Secondly is th

Solution 1:

You can use the HttpURLConnection class (in java.net) to send a POST or GET HTTP request. It is the same as any other application that might want to send an HTTP request. The code to send an Http Request would look like this:

import java.net.*;
import java.io.*;
public class SendPostRequest {
  public static void main(String[] args) throws MalformedURLException, IOException {
    URL reqURL = new URL("http://www.stackoverflow.com/"); //the URL we will send the request to
    HttpURLConnection request = (HttpURLConnection) (reqUrl.openConnection());
    String post = "this will be the post data that you will send"
    request.setDoOutput(true);
    request.addRequestProperty("Content-Length", Integer.toString(post.length)); //add the content length of the post data
    request.addRequestProperty("Content-Type", "application/x-www-form-urlencoded"); //add the content type of the request, most post data is of this type
    request.setMethod("POST");
    request.connect();
    OutputStreamWriter writer = new OutputStreamWriter(request.getOutputStream()); //we will write our request data here
    writer.write(post);
    writer.flush();
  }
}

A GET request will look a little bit different, but much of the code is the same. You don't have to worry about doing output with streams or specifying the content-length or content-type:

import java.net.*;
import java.io.*;

public class SendPostRequest {
  public static void main(String[] args) throws MalformedURLException, IOException {
    URL reqURL = new URL("http://www.stackoverflow.com/"); //the URL we will send the request to
    HttpURLConnection request = (HttpURLConnection) (reqUrl.openConnection());
    request.setMethod("GET");
    request.connect();

  }
}

Solution 2:

I prefer using dedicated class to do GET/POST and any HTTP connections or requests. Moreover I use HttpClient to execute these GET/POST methods.

Below is sample from my project. I needed thread-safe execution so there is ThreadSafeClientConnManager.

There is an example of using GET (fetchData) and POST (sendOrder)

As you can see execute is general method for executing HttpUriRequest - it can be POST or GET.

public final class ClientHttpClient {

private static DefaultHttpClient client;
private static CookieStore cookieStore;
private static HttpContext httpContext;

static {
    cookieStore = new BasicCookieStore();
    httpContext = new BasicHttpContext();
    httpContext.setAttribute(ClientContext.COOKIE_STORE, cookieStore);
    client = getThreadSafeClient();
    HttpParams params = new BasicHttpParams();
    HttpConnectionParams.setConnectionTimeout(params, AppConstants.CONNECTION_TIMEOUT);
    HttpConnectionParams.setSoTimeout(params, AppConstants.SOCKET_TIMEOUT);
    client.setParams(params);
}

private static DefaultHttpClient getThreadSafeClient() {
    DefaultHttpClient client = new DefaultHttpClient();
    ClientConnectionManager mgr = client.getConnectionManager();
    HttpParams params = client.getParams();
    client = new DefaultHttpClient(new ThreadSafeClientConnManager(params, mgr.getSchemeRegistry()),
            params);
    return client;
}

private ClientHttpClient() {
}

public static String execute(HttpUriRequest http) throws IOException {
    BufferedReader reader = null;
    try {
        StringBuilder builder = new StringBuilder();
        HttpResponse response = client.execute(http, httpContext);
        StatusLine statusLine = response.getStatusLine();
        int statusCode = statusLine.getStatusCode();
        HttpEntity entity = response.getEntity();
        InputStream content = entity.getContent();
        reader = new BufferedReader(new InputStreamReader(content, CHARSET));
        String line = null;
        while((line = reader.readLine()) != null) {
            builder.append(line);
        }

        if(statusCode != 200) {
            throw new IOException("statusCode=" + statusCode + ", " + http.getURI().toASCIIString()
                    + ", " + builder.toString());
        }

        return builder.toString();
    }
    finally {
        if(reader != null) {
            reader.close();
        }
    }
}


public static List<OverlayItem> fetchData(Info info) throws JSONException, IOException {
    List<OverlayItem> out = new LinkedList<OverlayItem>();
    HttpGet request = buildFetchHttp(info);
    String json = execute(request);
    if(json.trim().length() <= 2) {
        return out;
    }
    try {
        JSONObject responseJSON = new JSONObject(json);
        if(responseJSON.has("auth_error")) {
            throw new IOException("auth_error");
        }
    }
    catch(JSONException e) {
        //ok there was no error, because response is JSONArray - not JSONObject
    }

    JSONArray jsonArray = new JSONArray(json);
    for(int i = 0; i < jsonArray.length(); i++) {
        JSONObject chunk = jsonArray.getJSONObject(i);
        ChunkParser parser = new ChunkParser(chunk);
        if(!parser.hasErrors()) {
            out.add(parser.parse());
        }
    }
    return out;
}

private static HttpGet buildFetchHttp(Info info) throws UnsupportedEncodingException {
    StringBuilder builder = new StringBuilder();
    builder.append(FETCH_TAXIS_URL);
    builder.append("?minLat=" + URLEncoder.encode("" + mapBounds.getMinLatitude(), ENCODING));
    builder.append("&maxLat=" + URLEncoder.encode("" + mapBounds.getMaxLatitude(), ENCODING));
    builder.append("&minLon=" + URLEncoder.encode("" + mapBounds.getMinLongitude(), ENCODING));
    builder.append("&maxLon=" + URLEncoder.encode("" + mapBounds.getMaxLongitude(), ENCODING));
    HttpGet get = new HttpGet(builder.toString());
    return get;
}

public static int sendOrder(OrderInfo info) throws IOException {
    HttpPost post = new HttpPost(SEND_ORDER_URL);
    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
    nameValuePairs.add(new BasicNameValuePair("id", "" + info.getTaxi().getId()));
    nameValuePairs.add(new BasicNameValuePair("address", info.getAddressText()));
    nameValuePairs.add(new BasicNameValuePair("name", info.getName()));
    nameValuePairs.add(new BasicNameValuePair("surname", info.getSurname()));
    nameValuePairs.add(new BasicNameValuePair("phone", info.getPhoneNumber()));
    nameValuePairs.add(new BasicNameValuePair("passengers", "" + info.getPassengers()));
    nameValuePairs.add(new BasicNameValuePair("additionalDetails", info.getAdditionalDetails()));
    nameValuePairs.add(new BasicNameValuePair("lat", "" + info.getOrderLocation().getLatitudeE6()));
    nameValuePairs.add(new BasicNameValuePair("lon", "" + info.getOrderLocation().getLongitudeE6()));
    post.setEntity(new UrlEncodedFormEntity(nameValuePairs));

    String response = execute(post);
    if(response == null || response.trim().length() == 0) {
        throw new IOException("sendOrder_response_empty");
    }

    try {
        JSONObject json = new JSONObject(response);
        int orderId = json.getInt("orderId");
        return orderId;
    }
    catch(JSONException e) {
        throw new IOException("sendOrder_parsing: " + response);
    }
}

EDIT

The execute method is public because sometimes I use custom (or dynamic) GET/POST requests.

If you have URL object you can pass to execute method:

Baca Juga

HttpGet request = new HttpGet(url.toString());
execute(request);

Solution 3:

As you said: the GET-Parameters are in the URL - So you can use a loadUrl() on your Webview to send them.

[..].loadUrl("http://www.example.com/data.php?param1=value1&param2=value2&...");

Solution 4:

The developer training docs have a good example on GET requests. You're responsible for adding the query parameters to the URL.

Post is similar, but as you said, quite different. The HttpConnectionURLConnection class can do both, and it's easy to just set the post body with an output stream.

Solution 5:

 protected String doInBackground(String... strings) {
        String response = null;
        String data = null;
        try {
            data = URLEncoder.encode("CustomerEmail", "UTF-8")
                    + "=" + URLEncoder.encode(username, "UTF-8");

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        String url = Constant.URL_FORGOT_PASSWORD;// this is url 
        response = ServiceHandler.postData(url,data);
        if (response.equals("")){
            return response;
        }else {
            return response;
        }

    }


public static String postData(String urlpath,String data){

    String text = "";
    BufferedReader reader=null;
    try
    {
        // Defined URL  where to send data
        URL url = new URL(urlpath);

        // Send POST data request
        URLConnection conn = url.openConnection();
        conn.setDoOutput(true);
        OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
        wr.write( data );
        wr.flush();

        // Get the server response
        reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        StringBuilder sb = new StringBuilder();
        String line = null;

        // Read Server Response
        while((line = reader.readLine()) != null)
        {
            sb.append(line + "\n");
        }
        text = sb.toString();
        return text;
    }
    catch(Exception ex)
    {
    }
    finally
    {
        try
        {
            reader.close();
        }
        catch(Exception ex) {}
    }
    return text;
}

Android Coder