I am basically trying to send a message from my android to my server and the server to send back a response to my android app. I followed THIS tutorial.
Just a simple exercise to introduce myself in to SignalR using Azure Web API and Android.
My Complete Server code in C#:
public class TestHub: Hub {
public void SendMessage(string name, string message) {
// Call the broadcastMessage method to update clients.
Clients.All.broadcastMessage(name, message);
}
public void SendClientMessage(CustomType obj) {
Clients.All.broadcastMessage("From Server", "Server got the message bro");
}
public class CustomType {
public string Name;
public int Id;
}
}
Complete Android Java code:
public class MainActivity extends AppCompatActivity {
Handler handler;
TextView statustext;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
handler = new Handler();
statustext = (TextView) findViewById(R.id.status);
Platform.loadPlatformComponent(new AndroidPlatformComponent());
// Change to the IP address and matching port of your SignalR server.
String host = "https://My-Service-name.azure-mobile.net/";
HubConnection connection = new HubConnection(host);
HubProxy hub = connection.createHubProxy("TestHub");
SignalRFuture < Void > awaitConnection = connection.start();
try {
awaitConnection.get();
} catch (InterruptedException e) {
} catch (ExecutionException e) {
}
hub.subscribe(this);
try {
hub.invoke("SendMessage", "Client", "Hello Server!").get();
hub.invoke("SendClientMessage",
new CustomType() {
{
Name = "Android Homie";
Id = 42;
}
}).get();
} catch (InterruptedException e) {
} catch (ExecutionException e) {
}
}
//I have no idea what the following method is for. Just followed the tutorial.. (blindly)
public void UpdateStatus(String status) {
final String fStatus = status;
handler.post(new Runnable() {
#Override
public void run() {
statustext.setText(fStatus);
}
});
}
public class CustomType {
public String Name;
public int Id;
}
}
Problems with this:
1. I get an exception:
java.util.concurrent.ExecutionException:
microsoft.aspnet.signalr.client.transport.NegotiationException: There
was a problem in the negotiation with the server
2. I feel like I haven't properly called the server from the Java code.
Should the URL be:
https://My-Service-name.azure-mobile.net/
or
https://My-Service-name.azure-mobile.net/api/signalr
Can someone clarify these doubts and help me set it up?
I am working on an IM application with open fire server. I'm implementing Sync Adapter for managing the contacts.
From my sync adapter's onPerformSync() if I access the connection object which I kept in my Application class it returns null.
What am I doing wrong? How should I do that?
My Application class
public class MyApp extends Application {
private Connection connection;
private static MyApp instance;
public static MyApp getInstance() {
return instance;
}
public static void setInstance(MyApp instance) {
MyApp.instance = instance;
}
#Override
public void onCreate() {
super.onCreate();
instance = new MyApp();
}
public Connection getAuthenticatedConnection() throws NullPointerException {
if (instance.connection != null
&& instance.connection.isAuthenticated()) {
return instance.connection;
} else {
// Calling service which will create connection and update the object
Intent intent = new Intent(IM_Service_IntentMessaging.ACTION);
intent = new Intent(getContext(), IM_Service_IntentMessaging.class);
Bundle b = new Bundle();
b.putInt("key", IM_Service_IntentMessaging.KEY_CONNECTION);
intent.putExtras(b);
this.context.startService(intent);
throw new NullPointerException();
}
//service calls this method to update the object
public void setConnection(Connection connection) {
instance.connection = connection;
}
}
And my onPerformSync method is as follows...
#Override
public void onPerformSync(Account account, Bundle bundle, String authority,
ContentProviderClient provider, SyncResult syncResult) {
try {
this.connection = MyApp.getInstance()
.getAuthenticatedConnection();
this.roster = this.connection.getRoster();
} catch (NullPointerException e) {
//this line executes always
Log.e(TAG, "connection null...ending....");
return;
}
this.mAccount = account;
Log.d(TAG, "...onPerformSync...");
getAllContacts();
}
When I tried with creating break point in Application's getAuthenticatedConnection() method it didn't get triggered but the service IM_Service_IntentMessaging which i called from there to create connection is working.
I found the solution to my problem is i should remove the android:process=":sync" from the sync adapter's manifest file declaration. Because of that it treats like different process.
I'm trying to add import contacts from gmail account function in my android app. So the first problem is to get access token from gmail. I've found that there is GoogleAuthUtil class which can help me with it.
Here is my code:
private void importContactsFromGmail() {
showProgressDialog();
GetTokenTask getTokenTask = new GetTokenTask();
getTokenTask.execute();
String token = "";
try {
token = getTokenTask.get();
} catch (Exception e) {
e.printStackTrace();
}
System.out.println(token);
hideProgressDialog();
}
private class GetTokenTask extends AsyncTask<Void, Void, String> {
#Override
protected String doInBackground(Void... params) {
String token = "";
try {
token = GoogleAuthUtil.getToken(activity, <My_gmail_account>, "https://www.google.com/m8/feeds/");
} catch (Exception e) {
e.printStackTrace();
}
return token;
}
}
Now after calling GoogleAuthUtil.getToken my app completely freezes(no errors in Logcat). I completely stuck and I need your help.
What is wrong with my code? Maybe I should import contacts in some other way?
Not sure if this is related but calling the .get() method on the main thread is not correct because is blocking method.
What if you use the AsyncTask in this way?
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new GetTokenTask().execute();
}
static class GetTokenTask extends AsyncTask<Void, Void, String> {
#Override
protected String doInBackground(Void... unused) {
String token = "";
try {
token = GoogleAuthUtil.getToken(activity, <My_gmail_account>, "https://www.google.com/m8/feeds/");
} catch (Exception e) {
e.printStackTrace();
}
return token;
}
#Override
protected void onPostExecute(String token) {
Toast.makeText(MainActivity.this, token, Toast.LENGTH_SHORT).show();
}
}
}
(I wrote without compiling it, maybe it needs to be adjusted)
On Android devices, Gmail contacts are synced locally onto the device and are available via a public Contacts Provider, therefore there's no reason you'd need to use the Google API to pull what is already available. There is a whole training series dedicated specifically to retrieving a list of contacts.
Note that the Contacts training series does assume you have knowledge of Content Providers already, so it may be helpful to read up on the basics of Content Providers as well.
I'm trying to get the Salesforce REST API working with Android and new to android programming, followed the sample code to connect with SFDC http://wiki.developerforce.com/page/Getting_Started_with_the_Mobile_SDK_for_Android#Authentication
I'm trying to get a few records from SFDC and display them in the android app, looks like when the Async Call is made at "client.sendAsync(sfRequest, new AsyncRequestCallback()" - NullPointerException is thrown.
I did see a couple of similar issues online, but didn't help me. Hoping if some one would point me in the right direction to troubleshoot this. Thanks much.
public class GetAccountsActivity extends Activity {
private PasscodeManager passcodeManager;
private String soql;
private String apiVersion;
private RestClient client;
private TextView resultText;
private RestRequest sfRequest;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get Api Version
apiVersion = getString(R.string.api_version);
//Create Query
soql = "select id, name from Account limit 10";
// Setup view
setContentView(R.layout.get_accounts_activity);
((TextView) findViewById(R.id.Acc_Title)).setText(apiVersion);
// Passcode manager
passcodeManager = ForceApp.APP.getPasscodeManager();
}
#Override
public void onResume() {
super.onResume();
//Get SFClient
// Login options
String accountType = ForceApp.APP.getAccountType();
LoginOptions loginOptions = new LoginOptions(
null, // login host is chosen by user through the server picker
ForceApp.APP.getPasscodeHash(),
getString(R.string.oauth_callback_url),
getString(R.string.oauth_client_id),
new String[] {"api"});
new ClientManager(this, accountType, loginOptions).getRestClient(this, new RestClientCallback() {
#Override
public void authenticatedRestClient(RestClient client) {
if (client == null) {
ForceApp.APP.logout(GetAccountsActivity.this);
return;
}
GetAccountsActivity.this.client = client;
}
});
//Get Rest Object to query
try {
sfRequest = RestRequest.getRequestForQuery(apiVersion, soql);
//Use SF Rest Client to send the request
client.sendAsync(sfRequest, new AsyncRequestCallback(){
#Override
public void onSuccess(RestRequest request, RestResponse response){
//Check responses and display results
// EventsObservable.get().notifyEvent(EventType.RenditionComplete);
}//end onSuccess
#Override
public void onError(Exception exception) {
//printException(exception);
EventsObservable.get().notifyEvent(EventType.RenditionComplete);
}//End Exception for Async Method
});
}catch (UnsupportedEncodingException e) {
//printHeader("Could Send Query request");
//printException(e);
return;
}
}
}
enter code here
You are calling client.sendAsync from onResume() but client is not set until the authenticatedRestClient callback is called, you need to move your sendAsync call into the authenticatedRestClient callback.
I'm writing an application that validates login credentials on an external webserver - so I have the basic issue of creating a login screen that when submitted will send an HTTP request to a server in the background and not cause the UI to hang - whilst providing a ProgressDialog to the user.
My problem lies in, I want to write a generic HTTP Request class that extends AsyncTask, so when I call .execute() I will then pass String parameters which may contain something like 'post', and when doInBackground is called this will see the 'post' string and then forward those parameters onto the respective call in my class. Pseudo code would be something like
public class HTTPOperations extends AsyncTask<String, Void, String>
{
doInBackground(String... string1,additionalParams)
{
if string1.equals "post"
response = httpPost(additionalParams)
return response;
}
httpPost(params)
{
// do http post request
}
}
This is all I could think of, other than creating a class for every HTTP Post/GET etc request I wish to make and extending ASyncTask...
Which leads me to my next problem, if the HTTP POST is successful and it returns an authentication token, how do I access this token?
Because new httpOperations.execute(), does not return the string from doInBackground, but a value of type
Sorry if this doesn't make sense, I can't figure this out at all. Please ask for elaboration if you need it. AsyncTask design patterns and ideas are hugely welcomed.
If you are designing a reusable task for something like this, you need to identify a reusable return type. Its a design decision on your part. Ask yourself, "Are my HTTP operations similar in both the mechanisms with which they are called and in which their data is processed?" If so, you can design a single class to do both. If not, you probably need different classes for your different remote operations.
In my personal use, I have an object i attach key value pairs to and the common return type is the HttpEntity. This is the return type for both HTTP Get and Post, and this seems to work ok in my scenarios because i throw exceptions in exceptional HTTP result situations, like 404. Another nice aspect of this setup is that the code to attach parameters to a get or post are fairly similar, so this logic is pretty easy to construct.
An example would be something like this (psuedo):
public interface DownloadCallback {
void onSuccess(String downloadedString);
void onFailure(Exception exception);
}
Then in your code, where you go to do the download:
DownloadCallback dc = new DownloadCallback(){
public void onSuccess(String downloadedString){
Log.d("TEST", "Downloaded the string: "+ downloadedString);
}
public void onFailure(Exception e){
Log.d("TEST", "Download had a serious failure: "+ e.getMessage());
}
}
DownloadAsyncTask dlTask = new DownloadAsyncTask(dc);
Then inside the constructor of DownloadAsyncTask, store the DownloadCallback and, when the download is complete or fails, call the method on the download callback that corresponds to the event. So...
public class DownloadAsyncTask extends AsyncTask <X, Y, Z>(){
DownloadCallback dc = null;
DownloadAsyncTask(DownloadCallback dc){
this.dc = dc;
}
... other stuff ...
protected void onPostExecute(String string){
dc.onSuccess(string);
}
}
I'm going to reiterate that I think for the good of yourself, you should pass back HttpEntities. String may seem like a good idea now, but it really leads to trouble later when you want to do more sophisticated logic behind your http calls. Of course, thats up to you. Hopefully this helps.
suppose the data format with web api is json, my design pattern :
common classes
1.MyAsyncTask : extends AsyncTask
2.BackgroundBase : parameters to server
3.API_Base : parameters from server
4.MyTaskCompleted : callback interface
public class MyAsyncTask<BackgroundClass extends BackgroundBase,APIClass extends API_Base> extends AsyncTask<BackgroundClass, Void, APIClass> {
private ProgressDialog pd ;
private MyTaskCompleted listener;
private Context cxt;
private Class<APIClass> resultType;
private String url;
private int requestCode;
public MyAsyncTask(MyTaskCompleted listener, Class<APIClass> resultType, int requestCode, String url){
this.listener = listener;
this.cxt = (Context)listener;
this.requestCode = requestCode;
this.resultType = resultType;
this.url = url;
}
public MyAsyncTask(MyTaskCompleted listener, Class<APIClass> resultType, int requestCode, String url, ProgressDialog pd){
this(listener, resultType, requestCode, url);
this.pd = pd;
this.pd.show();
}
#Override
protected APIClass doInBackground(BackgroundClass... params) {
APIClass result = null;
try {
//do something with url and params, and get data from WebServer api
BackgroundClass oParams = params[0];
String sUrl = url + "?d=" + URLEncoder.encode(oParams.getJSON(), "UTF-8");
String source = "{\"RtnCode\":1, \"ResultA\":\"result aaa\", \"ResultB\":\"result bbb\"}";
//to see progressdialog
Thread.sleep(2000);
result = new com.google.gson.Gson().fromJson(source, resultType);
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
#Override
protected void onPostExecute(APIClass result) {
super.onPostExecute(result);
try {
if(pd != null && pd.isShowing())
pd.dismiss();
API_Base oApi_Base = (API_Base)result;
listener.onMyTaskCompleted(result , this.requestCode);
} catch (Exception e) {
e.printStackTrace();
}
}
}
public class API_Base {
public int RtnCode;
public String getJSON(Context context) throws Exception
{
return new com.google.gson.Gson().toJson(this);
}
public String toString(){
StringBuilder sb = new StringBuilder();
for (Field field : this.getClass().getFields()) {
try {
field.setAccessible(true);
Object value = field.get(this);
if (value != null) {
sb.append(String.format("%s = %s\n", field.getName(), value));
}
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
return sb.toString();
}
}
public class BackgroundBase {
public String getJSON() throws Exception
{
return new com.google.gson.Gson().toJson(this);
}
}
public interface MyTaskCompleted {
void onMyTaskCompleted(API_Base oApi_Base, int requestCode) ;
}
example, let's call two api in one activity
assume :
API 1.http://www.google.com/action/a
input params : ActionA
output params : RtnCode, ResultA
API 2.http://www.google.com/action/b
input params : ActionB
output params : RtnCode, ResultB
classes with example :
1.MyActivity : extends Activity and implements MyTaskCompleted
2.MyConfig : utility class, i set requestCode here
3.BackgroundActionA, BackgroundActionB : model classes for api's input params
4.API_ActionA, API_ActionB : model classes for api's output params
public class MyActivity extends Activity implements MyTaskCompleted {
ProgressDialog pd;
Button btnActionA, btnActionB;
TextView txtResult;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.my_layout);
btnActionA = (Button)findViewById(R.id.btn_actionA);
btnActionB = (Button)findViewById(R.id.btn_actionB);
txtResult = (TextView)findViewById(R.id.txt_result);
btnActionA.setOnClickListener(listener_ActionA);
btnActionB.setOnClickListener(listener_ActionB);
pd = new ProgressDialog(MyActivity.this);
pd.setTitle("Title");
pd.setMessage("Loading");
}
Button.OnClickListener listener_ActionA = new Button.OnClickListener(){
#Override
public void onClick(View v) {
//without ProgressDialog
BackgroundActionA oBackgroundActionA = new BackgroundActionA("AAA");
new MyAsyncTask<BackgroundActionA, API_ActionA>(MyActivity.this,
API_ActionA.class,
MyConfig.RequestCode_actionA,
"http://www.google.com/action/a").execute(oBackgroundActionA);
}
};
Button.OnClickListener listener_ActionB = new Button.OnClickListener(){
#Override
public void onClick(View v) {
//has ProgressDialog
BackgroundActionB oBackgroundActionB = new BackgroundActionB("BBB");
new MyAsyncTask<BackgroundActionB, API_ActionB>(MyActivity.this,
API_ActionB.class,
MyConfig.RequestCode_actionB,
"http://www.google.com/action/b",
MyActivity.this.pd).execute(oBackgroundActionB);
}
};
#Override
public void onMyTaskCompleted(API_Base oApi_Base, int requestCode) {
// TODO Auto-generated method stub
if(requestCode == MyConfig.RequestCode_actionA){
API_ActionA oAPI_ActionA = (API_ActionA)oApi_Base;
txtResult.setText(oAPI_ActionA.toString());
}else if(requestCode == MyConfig.RequestCode_actionB){
API_ActionB oAPI_ActionB = (API_ActionB)oApi_Base;
txtResult.setText(oAPI_ActionB.toString());
}
}
}
public class MyConfig {
public static String LogTag = "henrytest";
public static int RequestCode_actionA = 1001;
public static int RequestCode_actionB = 1002;
}
public class BackgroundActionA extends BackgroundBase {
public String ActionA ;
public BackgroundActionA(String actionA){
this.ActionA = actionA;
}
}
public class BackgroundActionB extends BackgroundBase {
public String ActionB;
public BackgroundActionB(String actionB){
this.ActionB = actionB;
}
}
public class API_ActionA extends API_Base {
public String ResultA;
}
public class API_ActionB extends API_Base {
public String ResultB;
}
Advantage with this design pattern :
1.one Advantage for multi api
2.just add model classes for new api, ex: BackgroundActionA and API_ActionA
3.determine which API by different requestCode in callback function : onMyTaskCompleted