问题
I use signalR lib in my project. but I was not able to compile libs of https://github.com/SignalR/java-client on my own - I found them in internet. But it seems like there are not full (WebsocketTransport is missing)
When I compile https://github.com/SignalR/java-client, i get two libs, and paste them to my app.gradle -
compile files ('libs/signalr-client-sdk.jar')
compile files ('libs/signalr-client-sdk-android.jar')
Progects build suckesfully, butwhen I press run - it fails. Here is stack trace -
UNEXPECTED TOP-LEVEL EXCEPTION:
com.android.dx.cf.iface.ParseException: bad class file magic (cafebabe) or version (0034.0000)
at com.android.dx.cf.direct.DirectClassFile.parse0(DirectClassFile.java:472)
at com.android.dx.cf.direct.DirectClassFile.parse(DirectClassFile.java:406)
at com.android.dx.cf.direct.DirectClassFile.parseToInterfacesIfNecessary(DirectClassFile.java:388)
at com.android.dx.cf.direct.DirectClassFile.getMagic(DirectClassFile.java:251)
at com.android.dx.command.dexer.Main.processClass(Main.java:704)
at com.android.dx.command.dexer.Main.processFileBytes(Main.java:673)
at com.android.dx.command.dexer.Main.access$300(Main.java:83)
at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:602)
at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:284)
at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:166)
at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:144)
at com.android.dx.command.dexer.Main.processOne(Main.java:632)
at com.android.dx.command.dexer.Main.processAllFiles(Main.java:510)
at com.android.dx.command.dexer.Main.runMonoDex(Main.java:280)
at com.android.dx.command.dexer.Main.run(Main.java:246)
at com.android.dx.command.dexer.Main.main(Main.java:215)
at com.android.dx.command.Main.main(Main.java:106)
...while parsing microsoft/aspnet/signalr/client/Action.class
1 error; aborting Error:Execution failed for task ':app:preDexDebug'.
com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process 'command 'C:\Program Files\Java\jdk1.8.0_45\bin\java.exe'' finished with non-zero exit value 1
I do not know what to do. I even tried to compile forks of this project, but have got the same result, same error. Need any help, Thanks!
UPDATE
in my Application class i have
Platform.loadPlatformComponent(new AndroidPlatformComponent());
in my app.gradle:
compile files ('libs/gson-2.2.2.jar')
compile files ('libs/signalr-client-sdk.jar')
compile files ('libs/signalr-client-sdk-android.jar')
in my code I use
connection.start(new ServerSentEventsTransport(connection.getLogger())).get();
I also create lots of hubs on this connection, nad call methods. All works, but connection always dissapears, if i do not do anything with device more then for 30 seconds. And I do not have any callbacks that the connection was lost\disconected or anything like that - I log all this stuff. But I think it can happen because i have pretty old libs, i googled - as I mention in this question i did not menaged to build signalR project to receive more recent libs
回答1:
Here is my working basic code, hope this helps!
package com.example.simplesignalrclient;
import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
import android.util.Log;
import android.widget.Toast;
import java.util.concurrent.ExecutionException;
import microsoft.aspnet.signalr.client.Credentials;
import microsoft.aspnet.signalr.client.Platform;
import microsoft.aspnet.signalr.client.SignalRFuture;
import microsoft.aspnet.signalr.client.http.Request;
import microsoft.aspnet.signalr.client.http.android.AndroidPlatformComponent;
import microsoft.aspnet.signalr.client.hubs.HubConnection;
import microsoft.aspnet.signalr.client.hubs.HubProxy;
import microsoft.aspnet.signalr.client.hubs.SubscriptionHandler1;
import microsoft.aspnet.signalr.client.transport.ClientTransport;
import microsoft.aspnet.signalr.client.transport.ServerSentEventsTransport;
public class SignalRService extends Service {
private HubConnection mHubConnection;
private HubProxy mHubProxy;
private Handler mHandler; // to display Toast message
private final IBinder mBinder = new LocalBinder(); // Binder given to clients
public SignalRService() {
}
@Override
public void onCreate() {
super.onCreate();
mHandler = new Handler(Looper.getMainLooper());
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
int result = super.onStartCommand(intent, flags, startId);
startSignalR();
return result;
}
@Override
public void onDestroy() {
mHubConnection.stop();
super.onDestroy();
}
@Override
public IBinder onBind(Intent intent) {
// Return the communication channel to the service.
startSignalR();
return mBinder;
}
/**
* Class used for the client Binder. Because we know this service always
* runs in the same process as its clients, we don't need to deal with IPC.
*/
public class LocalBinder extends Binder {
public SignalRService getService() {
// Return this instance of SignalRService so clients can call public methods
return SignalRService.this;
}
}
/**
* method for clients (activities)
*/
public void sendMessage(String message) {
String SERVER_METHOD_SEND = "Send";
mHubProxy.invoke(SERVER_METHOD_SEND, message);
}
private void startSignalR() {
Platform.loadPlatformComponent(new AndroidPlatformComponent());
Credentials credentials = new Credentials() {
@Override
public void prepareRequest(Request request) {
request.addHeader("User-Name", "BNK");
}
};
String serverUrl = "http://192.168.1.100";
mHubConnection = new HubConnection(serverUrl);
mHubConnection.setCredentials(credentials);
String SERVER_HUB_CHAT = "ChatHub";
mHubProxy = mHubConnection.createHubProxy(SERVER_HUB_CHAT);
ClientTransport clientTransport = new ServerSentEventsTransport(mHubConnection.getLogger());
SignalRFuture<Void> signalRFuture = mHubConnection.start(clientTransport);
try {
signalRFuture.get();
} catch (InterruptedException | ExecutionException e) {
e.printStackTrace();
return;
}
String HELLO_MSG = "Hello from Android!";
sendMessage(HELLO_MSG);
String CLIENT_METHOD_BROADAST_MESSAGE = "broadcastMessage";
mHubProxy.on(CLIENT_METHOD_BROADAST_MESSAGE,
new SubscriptionHandler1<CustomMessage>() {
@Override
public void run(final CustomMessage msg) {
final String finalMsg = msg.UserName + " says " + msg.Message;
// display Toast message
mHandler.post(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(), finalMsg, Toast.LENGTH_SHORT).show();
}
});
}
}
, CustomMessage.class);
}
}
Activity:
public class MainActivity extends AppCompatActivity {
private final Context mContext = this;
private SignalRService mService;
private boolean mBound = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent intent = new Intent();
intent.setClass(mContext, SignalRService.class);
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
}
@Override
protected void onStop() {
// Unbind from the service
if (mBound) {
unbindService(mConnection);
mBound = false;
}
super.onStop();
}
public void sendMessage(View view) {
if (mBound) {
// Call a method from the SignalRService.
// However, if this call were something that might hang, then this request should
// occur in a separate thread to avoid slowing down the activity performance.
EditText editText = (EditText) findViewById(R.id.edit_message);
if (editText != null && editText.getText().length() > 0) {
String message = editText.getText().toString();
mService.sendMessage(message);
}
}
}
/**
* Defines callbacks for service binding, passed to bindService()
*/
private final ServiceConnection mConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName className,
IBinder service) {
// We've bound to SignalRService, cast the IBinder and get SignalRService instance
SignalRService.LocalBinder binder = (SignalRService.LocalBinder) service;
mService = binder.getService();
mBound = true;
}
@Override
public void onServiceDisconnected(ComponentName arg0) {
mBound = false;
}
};
}
CustomMessage Class:
public class CustomMessage {
public String UserName;
public String Message;
}
回答2:
JUST TO HELP SOMEONE WHO GOT STUCK LIKE ME.
I was trying to get my SingalR to work. I followed the answer given but service was not firing. This was my first project to implement a service like SignalRService. So I did not know.
I added <service> entry to my manifest file then everything started working.
<service android:name=".SignalRService"
android:enabled="true"
android:exported="true">
</service>
Thanks a lot BNK
来源：https://stackoverflow.com/questions/32505390/signalr-integration-in-android-studio