I am trying to send an ArrayList to a client on an android device. The server says it sent the object however on the android device it hangs. I have read around that when creating an ObjectInputStream, an ObjectOuputStream must be created first and then flushed. I have tried that however this is not working for me. I didn't post the code for getting the clients as its just simply reading from a textfile. The Client class is very basic with few properties such as username, password and friends arraylist of strings. Any help would be much appreciated.
Server:
public class Server {
private static final int port = 9001;
private static final String IPAddr = "xxxxxxxxxxx";
ServerSocket server = null;
ArrayList <Client> users = new ArrayList<Client>();
public Server(){
try{
server = new ServerSocket(port);
System.out.println("connected server on port" + port);
while(true){
System.out.println("waiting for connection my ip add is "+ InetAddress.getLocalHost().getHostAddress());
Socket clientsocket = server.accept();
System.out.println("Connect to client:"+ clientsocket.getInetAddress().getHostName());
ClientThread client = new ClientThread(clientsocket);
client.start();
}
} catch(IOException e) {
System.err.println("Could not listen on port");
}
}
//Thread
public class ClientThread extends Thread {
private Socket sckt = null;
public ClientThread(Socket sckt){
super("ClientThread");
this.sckt = sckt;
}
public void run(){
try{
PrintWriter out = new PrintWriter(sckt.getOutputStream(), true);
BufferedReader input = new BufferedReader(new InputStreamReader(sckt.getInputStream()));
ObjectOutputStream objectOutput = new ObjectOutputStream(sckt.getOutputStream());
objectOutput.flush();
String Username = input.readLine();
String Password = input.readLine();
System.out.println("recieved from client: "+ Username);
int ClientIndex = isClient(Username);
if (ClientIndex != -1){
if(users.get(ClientIndex).password.equals(Password)){
//password correct -> send friends
out.println("correct");
out.flush();
System.out.println(Username + " is correct");
LoadClientFriends(Username, ClientIndex);
objectOutput.writeObject(users.get(ClientIndex).Friends);
System.out.println("Friends sent");
} else {
//password incorrect -> retry
out.println("password");
System.out.println(Username + " has wrong password");
}
} else {
//not a registered client
out.println("wrong");
System.out.println(Username + " is not a client");
}
} catch(Exception e){
System.err.println("Couldnt connect to Client socket");
}
}
}
public static void main(String[] args){
Server svr = new Server();
}
}
Client/Android:
public class MainActivity extends ActionBarActivity {
//Varibles
EditText username;
EditText password ;
private static final int port = 9001;
private static final String IPAddr = "xxxxxxx";
//Methods
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_main);
/* Drawable d = getResources().getDrawable(R.drawable.actionbar_background);
getActionBar().setBackgroundDrawable(d);*/
}
public void Login(View view) {
//connect to server
Thread myThread2 = new Thread(Connect);
myThread2.start();
}
public void Register(View view) {
Intent i = new Intent(this, register_screen.class);
startActivity(i);
}
Runnable Connect = new Runnable()
{
public void run()
{
try {
Socket connection = new Socket(IPAddr,port);
BufferedReader input = new BufferedReader(new InputStreamReader(connection.getInputStream()));
PrintWriter output = new PrintWriter(connection.getOutputStream(), true);
//Sent the username a password for verifaction
username = (EditText)findViewById(R.id.edtName);
password = (EditText)findViewById(R.id.edtPassword);
output.println(username.getText().toString());
output.flush();
output.println(password.getText().toString());
output.flush();
//Receive confirmation of client
String res = input.readLine();
if (res.contains("correct")){
ObjectOutputStream objectOutput = new ObjectOutputStream(connection.getOutputStream());
objectOutput.flush();
ObjectInputStream objectInput = new ObjectInputStream(new BufferedInputStream(connection.getInputStream())); //Error Line!
Object object = objectInput.readObject();
ArrayList<String> friends = (ArrayList<String>) object;
Intent intent = new Intent(MainActivity.this,chat_screen.class);
intent.putExtra("Friends", friends);
startActivity(intent);
}else if (res.contains("password")){
Intent i = new Intent(getBaseContext(), MainActivity.class);
startActivity(i);
}else {
}
}catch (Exception e){
}
}
};
}
The error you see is due to multiple output stream format. Stick to either ObjectOutputStream/ObjectInputStream or PrintWriter/BufferedReader. I suggest ObjectOutputStream/ObjectInputStream.
Server code: Use objectOutPut for all writes.
// out.println("correct");
objectOutput.writeUTF("correct");
// Update code for password and wrong too - Use objectOutput.writeUTF("");
Client code: Use just ObjectInputStream instead of BufferedReader
Define the objectInput here instead:
// BufferedReader input = new BufferedReader(new InputStreamReader(connection.getInputStream()));
ObjectInputStream objectInput = new ObjectInputStream(connection.getInputStream());
PrintWriter output = new PrintWriter(connection.getOutputStream(), true);
// Read data as follows:
// String res = input.readLine();
String res = objectInput.readUTF();