public class OkHttpDns implements Dns {
#NotNull
#Override
public List<InetAddress> lookup(#NotNull String hostname) throws UnknownHostException {
MyLookUpUtility.getInstance.lookup(hostname, new MyLookUpUtility.lookupCallback()
{
#Override
public void onlookupResponseSuccess(JSONObject nslookupResponseJSON) {
Log.d("LookupResponse", nslookupResponseJSON.toString());
}
#Override
public void onlookupResponseFailure(String errCode) {
Log.d("LookupResponse", "Error Code : "+errCode);
}
});
}
}
In the above code, lookup method of DNS interface of OKHttp wants to return immediately. But my custom NSLookupUtility is an asynchronous call and I will have the ip address of the hostname only after a while. How to solve this problem? how to make the synchronous call to wait for the asynchronous call within it ?
Take a look at CompletableFuture. You’ll create an instance in lookup(), kickoff the async lookup, and then call future.get(). When your async call completes, call future.complete().
#Override
public List<InetAddress> lookup(#NotNull String hostName) throws UnknownHostException {
completableFuture = new CompletableFuture<>();
performLookUp(hostName);
try {
String ipAddress = completableFuture.get();
if (ipAddress != null) {
List<InetAddress> inetAddresses = Arrays.asList(InetAddress.getAllByName(ipAddress));
return inetAddresses;
}
} catch (ExecutionException e) {
Log.d(TAG, "Error : ExecutionException : "+e );
e.printStackTrace();
} catch (InterruptedException e) {
Log.d(TAG, "Error : InterruptedException : "+e );
e.printStackTrace();
}
return Dns.SYSTEM.lookup(hostName);
}
private void performLookUp(#NotNull String hostName) {
MyUtiluty.getInstance().lookup(hostName,
new MyCallBack() {
#Override
public void onSuccess(String ip) {
completableFuture.complete(ip);
}
#Override
public void onFailure(String errCode) {
completableFuture.complete(null);
}
});
}
Related
I have a Observable like this
Observable<String> gitHubRepoModelObservable;
I have this code
repoNames = new ArrayList<String>();
gitHubRepoModelObservable = Observable.fromIterable(repoNames);
repoNames.add("Hello");
gitHubRepoModelObservable
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Observer<String>() {
#Override
public void onSubscribe(Disposable d) {
}
#Override
public void onNext(String s) {
System.out.println(s);
}
#Override
public void onError(Throwable e) {
}
#Override
public void onComplete() {
}
});
repoNames is just a list of string. When I am adding a string "hello" manually the onNext is getting called but when I am adding string from a API call like bellow
call.enqueue(new Callback<List<GitHubRepoModel>>() {
#Override
public void onResponse(Call<List<GitHubRepoModel>> call, Response<List<GitHubRepoModel>> response) {
for (GitHubRepoModel repo : response.body()) {
repoNames.add(repo.getName());
}
}
#Override
public void onFailure(Call<List<GitHubRepoModel>> call, Throwable t) {
}
});
I am adding strings from the API into the repoNames the "onNext" is not getting called.
I have seen
.addCallAdapterFactory(RxJava2CallAdapterFactory.create())
can be added while initializing retrofit but I want to better understand the rxjava so in this experiment it is not working.
Please help!
It can't not be work.
When you create you api request and try subscribe you list is emty, so Observable does not work.
You need to create Observable such, that your subcribe will run your request!
Observable<String> gitHubRepoModelObservable = Observable.create(
new Observable.OnSubscribe<String>() {
#Override
public void call(final Subscriber<? super String> sub) {
call.enqueue(new Callback<List<GitHubRepoModel>>() {
#Override
public void onResponse(Call<List<GitHubRepoModel>> call, Response<List<GitHubRepoModel>> response) {
for (GitHubRepoModel repo : response.body()) {
sub.onNext(repo.getName()); //send result to rx
}
sub.onCompleted();
}
#Override
public void onFailure(Call<List<GitHubRepoModel>> call, Throwable t) {
}
});
}
}
);
gitHubRepoModelObservable
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Observer<String>() {
#Override
public void onNext(String s) {
System.out.println(s);
}
#Override
public void onCompleted() {
}
#Override
public void onError(Throwable e) {
}
});
Why would onNext get called if you are just adding element to plain List?
In the first example you are seeing onNext being called because modified list is passed through the stream during subscribe.
Create Subject ex. PublishSubject and pass list to Subject.onNext in onResponse, subscribe to it and you will get what you want.
Second option is adding RxJava2CallAdapterFactory and return Observable<Response<List<GithubRepoModel>>>. This way you don't need to create stream yourself.
I want to save retrofit responses to realm on the background thread then pass it to the UI Thread, but its a bit tricky since Realm is very touchy with threads. so the code would look like something like this, please submit your edits to all better solutions :)
restApi.userRealmList()
.doOnNext(userRealmModels -> {
if (userRealmModels != null){
mRealm = Realm.getInstance(mContext);
mRealm.asObservable()
.map(realm -> mRealm.copyToRealmOrUpdate(userEntity))
.subscribe(new Subscriber<Object>() {
#Override
public void onCompleted() {
}
#Override
public void onError(Throwable e) {
e.printStackTrace();
}
#Override
public void onNext(Object o) {
Log.d("RealmManager", "user added!");
}
});
}})
.map(userEntityDataMapper::transformAll)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Subscriber<List<User>>() {
#Override
public void onCompleted() {
hideViewLoading();
}
#Override
public void onError(Throwable e) {
hideViewLoading();
showErrorMessage(new DefaultErrorBundle((Exception) e));
showViewRetry();
}
#Override
public void onNext(List<User> users) {
showUsersCollectionInView(users);
}
});
You code doesn't look like it can compile? E.g. what is userEntity. Also your copyToRealmOrUpdate isn't inside an transaction, so that will also crash, but it has nothing to do with threads.
If you want to save some data as a side-effect before sending it to the UI, you should be able to do the following:
restApi.userRealmList()
.doOnNext(userRealmModels -> {
if (userRealmModels != null) {
Realm realm = Realm.getInstance(mContext);
realm.beginTransaction();
realm.copyToRealmOrUpdate(userRealmModels);
realm.commitTransaction();
realm.close();
}})
.map(userEntityDataMapper::transformAll)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Subscriber<List<User>>() {
#Override
public void onCompleted() {
hideViewLoading();
}
#Override
public void onError(Throwable e) {
hideViewLoading();
showErrorMessage(new DefaultErrorBundle((Exception) e));
showViewRetry();
}
#Override
public void onNext(List<User> users) {
showUsersCollectionInView(users);
}
});
I cannot resolve a problem and need your help. When I click on menu I call customer account and then afterwards I close it. Every time I call customer account the memory increases. It should diminish when I close the account, but it does not happen.
Class Menu
mnItemCL_Cust.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent t) {
try {
panCenterPrev = (Pane) root.getCenter();
panCenterAct = Customer.listCustomer();
root.setCenter(null);
root.setCenter(panCenterAct);
Customer.btCanc.setOnAction(new EventHandler<ActionEvent>() {
#Override public void handle(ActionEvent e) {
try {
Customer.Fim();
panCenterAct.getChildren().clear();
panCenterAct = null;
root.setCenter(null);
root.setCenter(panCenterPrev);
} catch (Throwable ex) {
Logger.getLogger(Customer.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
Class Customer
public class Customer
{
public static Pane listCustomer() throws SQLException, ClassNotFoundException
{
...
final ObservableList<MyCustomer> data = FXCollections.observableArrayList();
...
}
public static class MyCustomer {
private final SimpleIntegerProperty idcl;
private MyCustomer(Integer pIdcl ) {
this.idcl = new SimpleIntegerProperty(pIdcl);
}
public Integer getIdcl() {
return idcl.get();
}
public void setIdcl(Integer pIdcl) {
idcl.set(pIdcl);
}
}
public static void Fim() throws Throwable {
...
rs = null;
tbViewCL.getItems().clear();
tbViewCL = null;
colIDCL.getColumns().clear();
colIDCL = null;
}
...
protected void finalize() throws Throwable {
try{
...
rs.close();
...// Never happens... why??
} catch(Throwable t) {
throw t;
} finally {
JOptionPane.showMessageDialog(null,"End?");
super.finalize();
}
}
Regards
Java usually reclaims the memory you used when it see it fits, so even if you finalize the object, the memory may still be there. However, if rs.Close() never executes, probably is because something before it is throwing and exception, i recommend you to check the code before just to be sure that nothing is doing so, also, if you catch an exception is a good practice to log it so you can know what is happening.
How to Implement a MIDlet that gets invoked when a SMS is sent to port 50000?
The code is not working. SMS can't be received on the phone, SMS is sent through the emulator (JAVA Me SDK).
What settings should be done to receive the SMS ?
my code:
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import java.io.IOException;
import javax.microedition.io.PushRegistry;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.MIDlet;
/**
* #author bonni
*/
public class Midletsms extends MIDlet implements CommandListener{
protected Display display;
//boolean started=false;
Form form = new Form("Welcome");
Command mCommandQuit;
public void startApp() {
String url = "sms://:50000";
try {
PushRegistry.registerConnection(url,this.getClass().getName(), "*");
// PushRegistry.registerConnection(url,"Midletsms.class", "*");
} catch (IOException ex) {
} catch (ClassNotFoundException ex) {
}
form.append("This midlet gets invoked when message is sent to port:50000");
display = Display.getDisplay(this);
display.setCurrent(form);
mCommandQuit = new Command("Quit", Command.EXIT, 0);
form.addCommand(mCommandQuit);
form.setCommandListener(this);
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
public void commandAction(Command c, Displayable d) {
// throw new UnsupportedOperationException("Not supported yet.");
String label = c.getLabel();
if(label.equals("Quit"))
{
destroyApp(false);
notifyDestroyed();
}
}
}
Not sure I fully understand the problem. But you need to read about PushRegistry.
So there are two types of push registration, static and dynamic.
The code example you have given uses dynamic registration. You will need to manually invoke this MIDlet at least once in order for the push registration to happen. (Aside: In your example you are doing this in the startApp method, this is a very bad idea! Push registration is a potentially blocking operation, and therefore should not be done in a lifecycle method such as startApp. You should do this in a new thread).
The alternative is static registration, where you include the push information in the jad. The push port will be registered when the MIDlet is installed, without the need to run it.
Finally, you say
sms is sent through the emulator
what does this mean? In order for the app to start you need to send an SMS on the relevant port number from another MIDlet (this could be on the same handset if you want).
I found this code on net from Jimmy's blog and it is perfectly working. You can try it your self,
SMSSender.java
public class SMSSender extends MIDlet implements CommandListener {
private Form formSender = new Form("SMS Sender");
private TextField tfDestination = new TextField("Destination", "", 20, TextField.PHONENUMBER);
private TextField tfPort = new TextField("Port", "50000", 6, TextField.NUMERIC);
private TextField tfMessage = new TextField("Message", "message", 150, TextField.ANY);
private Command cmdSend = new Command("Send", Command.OK, 1);
private Command cmdExit = new Command("Exit", Command.EXIT, 1);
private Display display;
public SMSSender() {
formSender.append(tfDestination);
formSender.append(tfPort);
formSender.append(tfMessage);
formSender.addCommand(cmdSend);
formSender.addCommand(cmdExit);
formSender.setCommandListener(this);
display = Display.getDisplay(this);
}
protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
}
protected void pauseApp() {
}
protected void startApp() throws MIDletStateChangeException {
display.setCurrent(formSender);
}
public void commandAction(Command c, Displayable d) {
if (c==cmdSend) {
SendMessage.execute(tfDestination.getString(), tfPort.getString(), tfMessage.getString());
} else if (c==cmdExit) {
notifyDestroyed();
}
}
}
class SendMessage {
public static void execute(final String destination, final String port, final String message) {
Thread thread = new Thread(new Runnable() {
public void run() {
MessageConnection msgConnection;
try {
msgConnection = (MessageConnection)Connector.open("sms://"+destination+":" + port);
TextMessage textMessage = (TextMessage)msgConnection.newMessage(
MessageConnection.TEXT_MESSAGE);
textMessage.setPayloadText(message);
msgConnection.send(textMessage);
msgConnection.close();
} catch (IOException e) {
e.printStackTrace();
}
}
});
thread.start();
}
}
SMSReceiver.java
public class SMSReceiver extends MIDlet implements CommandListener, MessageListener {
private Form formReceiver = new Form("SMS Receiver");
private TextField tfPort = new TextField("Port", "50000", 6, TextField.NUMERIC);
private Command cmdListen = new Command("Listen", Command.OK, 1);
private Command cmdExit = new Command("Exit", Command.EXIT, 1);
private Display display;
public SMSReceiver() {
formReceiver.append(tfPort);
formReceiver.addCommand(cmdListen);
formReceiver.addCommand(cmdExit);
formReceiver.setCommandListener(this);
display = Display.getDisplay(this);
}
protected void destroyApp(boolean unconditional)
throws MIDletStateChangeException {
}
protected void pauseApp() {
}
protected void startApp() throws MIDletStateChangeException {
display.setCurrent(formReceiver);
}
public void commandAction(Command c, Displayable d) {
if (c==cmdListen) {
ListenSMS sms = new ListenSMS(tfPort.getString(), this);
sms.start();
formReceiver.removeCommand(cmdListen);
} else if (c==cmdExit) {
notifyDestroyed();
}
}
public void notifyIncomingMessage(MessageConnection conn) {
Message message;
try {
message = conn.receive();
if (message instanceof TextMessage) {
TextMessage tMessage = (TextMessage)message;
formReceiver.append("Message received : "+tMessage.getPayloadText()+"\n");
} else {
formReceiver.append("Unknown Message received\n");
}
} catch (InterruptedIOException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
class ListenSMS extends Thread {
private MessageConnection msgConnection;
private MessageListener listener;
private String port;
public ListenSMS(String port, MessageListener listener) {
this.port = port;
this.listener = listener;
}
public void run() {
try {
msgConnection = (MessageConnection)Connector.open("sms://:" + port);
msgConnection.setMessageListener(listener);
} catch (IOException e) {
e.printStackTrace();
}
}
}
I want to create a MIDlet which automatically starts using push registry function
PushRegistry.RegisterConnection("sms://:50000", this.getclass().getname(),"*");
Following is the code which I have come up with, and cannot find the problem with it as it is not responding in any way to any message.
P.S. I am aware of the fact that dynamic registration requires me to first run the app once.
public class Midlet extends MIDlet implements CommandListener,Runnable {
private Display disp;
Form form = new Form("Welcome");
Command ok,exit;
public void startApp() {
String conn[];
exit= new Command("exit",Command.CANCEL,2);
ok= new Command("ok",Command.OK,2);
form.addCommand(ok);
form.addCommand(exit);
form.setCommandListener(this);
conn = PushRegistry.listConnections(true);
disp=Display.getDisplay(this);
disp.setCurrent(form);
form.append("Midlet");
form.append("Press OK to register sms connection");
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
notifyDestroyed();
}
public void commandAction(Command c, Displayable d) {
if(c.getLabel().equals("exit"))
{
System.out.println("exit pressed");
destroyApp(true);
}
if(c.getLabel().equals("ok"))
{
String[] cn;
cn=PushRegistry.listConnections(true);
form.append(""+cn.length);
for(int i=0;i<cn.length;i++)
{
form.append(cn[i]);
}
Thread t = new Thread(this);
t.start();
}
}
public void run() {
try {
PushRegistry.registerConnection("sms://:50000",this.getclass().getname, "*");
} catch (IOException ex) {
ex.printStackTrace();
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
}
}
Your code worked when I replaced this line PushRegistry.registerConnection("sms://:50000",this.getclass().getname, "*");
with PushRegistry.registerConnection("sms://:50000",<actual name of the class>, "*");