I’ve created a remote service that taking care for all client-server communication.
I use service because there are few separated applications that will use the same communication socket and there is no other way to “share” socket between applications (as far as i know).
The service works great, can start a socket connection and send int/String through it, but i can’t use it as input like readString().
I think the problem occurs because the activity never wait for reply from the service.
I tested it while returning custom strings in every part of my readString method on my service.
and for the code…
ConnectionRemoteService:
public class ConnectionRemoteService extends Service {
private String deviceID;
private ConnectionThread ct;
@Override
public void onCreate() {
super.onCreate();
//Toast.makeText(this, "Service On.", Toast.LENGTH_LONG).show();
}
@Override
public void onDestroy() {
//Toast.makeText(this, "Service Off.", Toast.LENGTH_LONG).show();
if(ct != null)
ct.close();
}
@Override
public IBinder onBind(Intent intent) {
return myRemoteServiceStub;
}
private ConnectionInterface.Stub myRemoteServiceStub = new ConnectionInterface.Stub() {
public void startConnection(){
WifiManager wm = (WifiManager)getSystemService(Context.WIFI_SERVICE);
deviceID = wm.getConnectionInfo().getMacAddress();
ct = new ConnectionThread(deviceID);
ct.start();
}
public void closeConnection(){
if(ct != null)
ct.close();
}
public void writeInt(int i) throws RemoteException {
if(ct != null)
ct.writeInt(i);
}
public int readInt() throws RemoteException {
if(ct != null)
return ct.readInt();
return 0;
}
public void writeString(String st) throws RemoteException {
if(ct != null)
ct.writeString(st);
}
public String readString() throws RemoteException {
if(ct != null)
return ct.readString();
return null;
}
public String deviceID() throws RemoteException {
return deviceID;
}
public boolean isConnected() throws RemoteException {
return ct.isConnected();
}
};
}
explanation:
as you can see, i only start an “empty” service and wait for application to bind with it.
after the bind, i create ConnectionThread that will take care for the socket etc…
all methods calls the thread methods for input \ output through the socket.
ConnectionThread:
public class ConnectionThread extends Thread {
private static final int SERVERPORT = 7777;
private static final String SERVERADDRESS = "192.168.1.106";
private String deviceID;
private Socket socket;
private DataInputStream in;
private DataOutputStream out;
private ObjectInputStream inObj;
private ObjectOutputStream outObj;
private boolean isConnected = false;
PingPongThread ppt;
public ConnectionThread(String deviceID) {
super();
this.deviceID = deviceID;
}
@Override
public void run() {
super.run();
open();
}
void open(){
try{
socket = new Socket(SERVERADDRESS,SERVERPORT);
out = new DataOutputStream(socket.getOutputStream());
out.flush();
in = new DataInputStream(socket.getInputStream());
outObj = new ObjectOutputStream(out);
outObj.flush();
inObj = new ObjectInputStream(in);
out.writeUTF(deviceID);
isConnected = true;
ppt = new PingPongThread(SERVERADDRESS, SERVERPORT);
ppt.start();
}
catch(Exception e){
isConnected = false;
System.err.println(e.getMessage());
}
}
public void close(){
try {
if(ppt!=null){
ppt.stopThread();
ppt.notify();
}
if(in!=null)
in.close();
if(out!=null)
out.close();
if(socket!=null)
socket.close();
}
catch(Exception e){
System.err.println(e.getMessage());
}
isConnected = false;
socket=null;
}
public void writeInt(int i){
try {
out.writeInt(i);
out.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
public int readInt(){
try {
int i = in.readInt();
return i;
} catch (IOException e) {
e.printStackTrace();
}
return 0;
}
public void writeString(String st){
try {
out.writeUTF(st);
out.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
public String readString(){
String st = "";
try {
st = in.readUTF();
return st;
} catch (IOException e) {
e.printStackTrace();
}
return st;
}
public boolean isConnected(){
return isConnected;
}
}
explanation:
in my thread, i create the socket and initialize all in/out objects to use later on.
(ignore the “PingPongThread”, it’s just a simple thread to check connection. it uses different port, so it can’t be the problem…)
all other methods are very simple, just using the in/out objects…
and for the main activity:
public class MainLauncherWindow extends Activity {
private ConnectionInterface myRemoteService;
private boolean isServiceBinded = false;
private OnClickListener onclicklistener;
final ServiceConnection conn = new ServiceConnection() {
public void onServiceConnected(ComponentName name, IBinder service) {
myRemoteService = ConnectionInterface.Stub.asInterface(service);
}
public void onServiceDisconnected(ComponentName name) {
myRemoteService = null;
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_launcher_window);
final Button connectButton = (Button)findViewById(R.id.Connect);
final Button disconnectButton = (Button)findViewById(R.id.Disconnect);
startService(new Intent(getApplicationContext(), ConnectionRemoteService.class));
isServiceBinded = bindService(new Intent("com.mainlauncher.ConnectionRemoteService"),conn,Context.BIND_AUTO_CREATE);
//Connect button
onclicklistener = new OnClickListener(){
public void onClick(View v) {
try {
if(isServiceBinded){
myRemoteService.startConnection();
connectButton.setEnabled(false);
disconnectButton.setEnabled(true);
}
} catch (Exception e) {
e.printStackTrace();
}
}
};
connectButton.setOnClickListener(onclicklistener);
//Disconnect button
onclicklistener = new OnClickListener(){
public void onClick(View v) {
connectButton.setEnabled(true);
disconnectButton.setEnabled(false);
try {
if(isServiceBinded)
myRemoteService.closeConnection();
} catch (RemoteException e) {
e.printStackTrace();
}
}
};
disconnectButton.setOnClickListener(onclicklistener);
//read test button
final Button bt1 = (Button)findViewById(R.id.bt1);
onclicklistener = new OnClickListener(){
public void onClick(View v) {
try {
if(isServiceBinded){
myRemoteService.writeString("Testing");
Toast.makeText(v.getContext(), myRemoteService.readString(), Toast.LENGTH_LONG).show();
}
} catch (RemoteException e) {
e.printStackTrace();
}
}
};
bt1.setOnClickListener(onclicklistener);
}
@Override
public void onBackPressed() {
super.onBackPressed();
if(isServiceBinded){
unbindService(conn);
stopService(new Intent(getApplicationContext(), ConnectionRemoteService.class));
isServiceBinded = false;
}
}
@Override
protected void onDestroy() {
super.onDestroy();
if(isServiceBinded){
unbindService(conn);
stopService(new Intent(getApplicationContext(), ConnectionRemoteService.class));
isServiceBinded = false;
}
}
}
in my main activity i created buttons for connect \ disconnect and test button.
the test button sends “Testing” string to the server side.
the server works fine, gets the “Testing” String and returns other string to the client.
but the “Toast” msg is blank always.
- i tested the server side without the service and it works fine, so no worries there.
- i had a test with the ConnectionThread, returning test string from it’s readString method and it worked well, means the thread returns an answer through the service to the client side (all the chain works well).
the only thing i have in mind now is that the activity never waits for a string back from the service and that’s what cause the problems.
any ideas?
thanks,
Lioz.
Try using AsyncTask instead of thread or wrap your thread in an AsyncTask(if it is possible i didnt tried it)
by doing that you can make your app wait for your result like this: