How to call asp.net Web API from android device - android

I have a web api controller:
// POST: api/CountriesAPI
[ResponseType(typeof(Country))]
public async Task<IHttpActionResult> PostCountry(Country country)
{
if (!ModelState.IsValid)
{
return BadRequest(ModelState);
}
db.Countries.Add(country);
await db.SaveChangesAsync();
return CreatedAtRoute("DefaultApi", new { id = country.CountryID }, country);
}
I don't know how how to consume this from android. please help.


I've used the Android HTTP Client available here and found it very simple and easy to use.
You can then do a POST with code something like below:
public class HTTPClient
{
private static AsyncHttpClient client = new AsyncHttpClient();
public static void get(String url, RequestParams params, AsyncHttpResponseHandler responseHandler)
{
client.get(url, params, responseHandler);
}
public static void get(String url, FileAsyncHttpResponseHandler responseHandler)
{
client.get(url, responseHandler);
}
public static void post(Context context, String url, StringEntity entity, String contentType, AsyncHttpResponseHandler responseHandler)
{
client.post(context, url, entity, contentType, responseHandler);
}
}
HTTPClient.post(this, <server_url>, entity, "application/json", new AsyncHttpResponseHandler() {
#Override
public void onSuccess(String response)
{
// Do Something
}
#Override
public void onFailure(Throwable error, String content)
{
// Do Something else
}
});


You can try Libraries like Volley (Requires you to write boilerplate code) or RetroFit
You can make get and post requests using them, do read about Pojos and model creation before you start. And also how do Callbacks work.

Related

Loopj - Uploading Files with RequestParams c# .net

Trying to upload a file with params using loopj.
im trying to get file from Request.Files and params from Request.Form["create"]
but it is not uploading to the server.
Android Post method
try {
String createTeamURL = "http://url";
RequestParams params = new RequestParams();
params.put("file", new File(pathoffile));
params.add("create", regString);
AsyncHttpClient client = new AsyncHttpClient();
client.post(createTeamURL, params, new AsyncHttpResponseHandler() {
#Override
public void onStart() {
// called before request is started
}
#Override
public void onSuccess(int statusCode, Header[] headers, byte[] response) {
// called when response HTTP status is "200 OK"
}
#Override
public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {
// called when response HTTP status is "4XX" (eg. 401, 403, 404)
}
#Override
public void onRetry(int retryNo) {
// called when request is retried
}
});
} catch (Exception e) {
Log.e("createTeamPreStep", e.getMessage());
}
My Web Api c# method
[HttpPost]
public async Task<string> CreateUHS()
{
var resultString = "";
foreach(HttpPostedFileBase s in Request.Files)
{
var a=s;
}
String sdf = Request.Form["create"];
}

You need to use put for string args.
please find the below both server and client methods.
and one more thing im really worried about your naming variable. its bad. please change it. Happy coding.
String createTeamURL = "http://url";
RequestParams params = new RequestParams();
params.put("file", new File(pathoffile));
params.put("create", regString);
Server (Web api)
[HttpPost]
public async Task<string> CreateUHS()
{
var file=Request.Files[0];
String otherArg = Request.Form["create"];
}

How do I call REST API from an android app? [closed]

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I'm new to android and new to programming as well. How do I call a REST api (GET/POST request) from an android app. Please suggest me a good tutorial, or give me an idea to start with.

If you want to integrate Retrofit (all steps defined here):
Goto my blog : retrofit with kotlin
Please use android-async-http library.
the link below explains everything step by step.
http://loopj.com/android-async-http/
Here are sample apps:
http://www.techrepublic.com/blog/software-engineer/calling-restful-services-from-your-android-app/
http://blog.strikeiron.com/bid/73189/Integrate-a-REST-API-into-Android-Application-in-less-than-15-minutes
Create a class :
public class HttpUtils {
private static final String BASE_URL = "http://api.twitter.com/1/";
private static AsyncHttpClient client = new AsyncHttpClient();
public static void get(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
client.get(getAbsoluteUrl(url), params, responseHandler);
}
public static void post(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
client.post(getAbsoluteUrl(url), params, responseHandler);
}
public static void getByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
client.get(url, params, responseHandler);
}
public static void postByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
client.post(url, params, responseHandler);
}
private static String getAbsoluteUrl(String relativeUrl) {
return BASE_URL + relativeUrl;
}
}
Call Method :
RequestParams rp = new RequestParams();
rp.add("username", "aaa"); rp.add("password", "aaa#123");
HttpUtils.post(AppConstant.URL_FEED, rp, new JsonHttpResponseHandler() {
#Override
public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
// If the response is JSONObject instead of expected JSONArray
Log.d("asd", "---------------- this is response : " + response);
try {
JSONObject serverResp = new JSONObject(response.toString());
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public void onSuccess(int statusCode, Header[] headers, JSONArray timeline) {
// Pull out the first event on the public timeline
}
});
Please grant internet permission in your manifest file.
<uses-permission android:name="android.permission.INTERNET" />
you can add compile 'com.loopj.android:android-async-http:1.4.9' for Header[] and compile 'org.json:json:20160212' for JSONObject in build.gradle file if required.

LoopJ Android Asynchronous Http Client onpostexecute?

I am making a GET call and am able to add all the results into an array after parsing the JSON. I want to use that array onpostexecute call. Can I do that with this library?

I do it in this way , hope it will help you.
in bussiness layer
HttpUtils.getJson(url, null, new JsonHttpResponseHandler() {
#Override
public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
}
});
in HttpUtils.java
private static AsyncHttpClient client = new AsyncHttpClient();
public static void get(String urlString, RequestParams params, AsyncHttpResponseHandler res) //url里面带参数
{
client.get(urlString, params, res);
}

Static Http Client not giving callbacks

I used Loopj Android library for Post requests it works fine when I don't use Static Http Client but when I use Static Http Client it does not give any callback here is my code for class of HttpClient
import com.loopj.android.http.*;
public class MyHttpClient {
private static final String BASE_URL = "http://www.google.com";
private static AsyncHttpClient client = new AsyncHttpClient();
public static void post(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
client.post(getAbsoluteUrl(url), params, responseHandler);
System.out.println("post called");
}
public static void get(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
client.get(getAbsoluteUrl(url), params, responseHandler);
}
private static String getAbsoluteUrl(String relativeUrl) {
return BASE_URL + relativeUrl;
}
}
Here is how I call it
MyHttpClient.post("", params, new AsyncHttpResponseHandler(){
#Override
public void onSuccess(String response) {
System.out.println(response);
}
});
and I have added Internet permission in manifest so there is no issue of permissions here
kindly help

POSTing JSON/XML using android-async-http (loopj)

I am using android-async-http and really liking it. I've run into a problem with POSTing data. I have to post data to the API in the following format: -
<request>
<notes>Test api support</notes>
<hours>3</hours>
<project_id type="integer">3</project_id>
<task_id type="integer">14</task_id>
<spent_at type="date">Tue, 17 Oct 2006</spent_at>
</request>
As per the documentation, I tried doing it using RequestParams, but it is failing. Is this any other way to do it? I can POST equivalent JSON too. Any ideas?

Loopj POST examples - extended from their Twitter example:
private static AsyncHttpClient client = new AsyncHttpClient();
To post normally via RequestParams:
RequestParams params = new RequestParams();
params.put("notes", "Test api support");
client.post(restApiUrl, params, responseHandler);
To post JSON:
JSONObject jsonParams = new JSONObject();
jsonParams.put("notes", "Test api support");
StringEntity entity = new StringEntity(jsonParams.toString());
client.post(context, restApiUrl, entity, "application/json",
responseHandler);

#Timothy answer did not work for me.
I defined the Content-Type of the StringEntity to make it work:
JSONObject jsonParams = new JSONObject();
jsonParams.put("notes", "Test api support");
StringEntity entity = new StringEntity(jsonParams.toString());
entity.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
client.post(context, restApiUrl, entity, "application/json", responseHandler);
Good Luck :)

a better way to post json
RequestParams params = new RequestParams();
params.put("id", propertyID);
params.put("lt", newPoint.latitude);
params.put("lg", newPoint.longitude);
params.setUseJsonStreamer(true);
ScaanRestClient restClient = new ScaanRestClient(getApplicationContext());
restClient.post("/api-builtin/properties/v1.0/edit/location/", params, new AsyncHttpResponseHandler() {
#Override
public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {
}
#Override
public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {
}
});

To post XML
protected void makePost() {
AsyncHttpClient client = new AsyncHttpClient();
Context context = this.getApplicationContext();
String url = URL_String;
String xml = XML-String;
HttpEntity entity;
try {
entity = new StringEntity(xml, "UTF-8");
} catch (IllegalArgumentException e) {
Log.d("HTTP", "StringEntity: IllegalArgumentException");
return;
} catch (UnsupportedEncodingException e) {
Log.d("HTTP", "StringEntity: UnsupportedEncodingException");
return;
}
String contentType = "string/xml;UTF-8";
Log.d("HTTP", "Post...");
client.post( context, url, entity, contentType, new AsyncHttpResponseHandler() {
#Override
public void onSuccess(String response) {
Log.d("HTTP", "onSuccess: " + response);
}
... other handlers
});
}

just write your xml or json to a string and send to server, with proper headers or without. and yes set "Content-Type" to "application/json"

If someone have a problem that httpclient send as Content-Type: text/plain, please refer this link: https://stackoverflow.com/a/26425401/361100
The loopj httpclient is somewhat changed (or has problem) which cannot override StringEntity native Content-Type to application/json.

You can add the JSON string as an InputStream of some kind - I've used the ByteArrayStream, then passing it to the RequestParams you should set the correctMimeType
InputStream stream = new ByteArrayInputStream(jsonParams.toString().getBytes(Charset.forName("UTF-8")));
multiPartEntity.put("model", stream, "parameters", Constants.MIME_TYPE_JSON);

Just make JSONObject and then convert it to String "someData" and simply send with "ByteArrayEntity"
private static AsyncHttpClient client = new AsyncHttpClient();
String someData;
ByteArrayEntity be = new ByteArrayEntity(someData.toString().getBytes());
client.post(context, url, be, "application/json", responseHandler);
It is working fine for me.

To post xml file to a php server :
public class MainActivity extends AppCompatActivity {
/**
* Send xml file to server via asynchttpclient lib
*/
Button button;
String url = "http://xxx/index.php";
String filePath = Environment.getExternalStorageDirectory()+"/Download/testUpload.xml";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button)findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
postFile();
}
});
}
public void postFile(){
Log.i("xml","Sending... ");
RequestParams params = new RequestParams();
try {
params.put("key",new File(filePath));
}catch (FileNotFoundException e){
e.printStackTrace();
}
AsyncHttpClient client = new AsyncHttpClient();
client.post(url, params, new AsyncHttpResponseHandler() {
#Override
public void onSuccess(int i, cz.msebera.android.httpclient.Header[] headers, byte[] bytes) {
Log.i("xml","StatusCode : "+i);
}
#Override
public void onFailure(int i, cz.msebera.android.httpclient.Header[] headers, byte[] bytes, Throwable throwable) {
Log.i("xml","Sending failed");
}
#Override
public void onProgress(long bytesWritten, long totalSize) {
Log.i("xml","Progress : "+bytesWritten);
}
});
}
}
After adding android-async-http-1.4.9.jar to android studio,
go to build.gradle and add :
compile 'com.loopj.android:android-async-http:1.4.9' under dependencies
And on AndroidManifest.xml add:
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

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