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android.os.NetworkOnMainThreadException but my class extends Thread

I have a client class that extends Thread to start socket programming
my class code
class MyClientMessages extends Thread {
Socket socket;
int PORT = 5002;
DataInputStream din;
DataOutputStream dout;
public MyClientMessages(String IP) {
try {
System.out.println("IP = ======= " + IP + " TYPE = " + TYPE);
//*********** crash here ***************
socket = new Socket(IP,PORT); // *********** it crash here *************
din = new DataInputStream(socket.getInputStream());
dout = new DataOutputStream(socket.getOutputStream());
this.start();
}catch (IOException e) {
e.printStackTrace();
}
}
#Override
public void run() {
while (true) {
byte[] data = new byte[1024];
int size = 0;
try {
while ((size = din.read(data)) > 0) {
final String str = new String(data,"UTF8");
runOnUiThread(new Runnable() {
#Override
public void run() {
TextView textView = new TextView(ServerChat.this);
textView.setTextSize(15);
textView.setText(str);
linearLayout.addView(textView);
}
});
}
}catch (IOException e) {
e.printStackTrace();
try {
dout.close();
din.close();
socket.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}
public void WriteToSocket(byte[] arr,int size) {
try {
dout.write(arr,0,size);
dout.flush();
}catch (IOException e) {
e.printStackTrace();
try {
dout.close();
din.close();
socket.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}
I make this class inside my activity class. I have another class inside my activity class for server, which extends thread and it works fine. Why does this client class crash and give me this error ?
this how I use it on my onCreate() function:
if (TYPE == 1) {
serverMessages = new MyServerMessages(5002);
Toast.makeText(this,"Room Started Wait clients To Join",Toast.LENGTH_LONG).show();
}
else {
clientMessages = new MyClientMessages(deConvert(mycode)); // crash here
Toast.makeText(this,"Connect To Room",Toast.LENGTH_LONG).show();
}

why this client class crash and give me this error ?
Because you are creating a Socket and opening it in the constructor. Move that logic into run().

Java Send custom object via socket Client, Server, LAN

I want to send object (custom class) via socket from Client to Server. This is my code:
Server:
private class SocketServerThread extends Thread {
#Override
public void run() {
try {
serverSocket = new ServerSocket(socketServerPORT);
while (true) {
clientSocket = serverSocket.accept();
ObjectInputStream inObject = new ObjectInputStream(
clientSocket.getInputStream());
try {
Te xxx = (Te) inObject.readObject();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
//DataInputStream dataInputStream = new DataInputStream(
//clientSocket.getInputStream());
//messageFromClient=dataInputStream.readUTF();
activity.runOnUiThread(new Runnable() {
#Override
public void run() {
//activity.msgFromC.setText(messageFromClient);
}
});
}
}
Client:
public Client(String aIPaddres, int aPort, Te u) {
AddressIP = aIPaddres;
Port = aPort;
sendUser = u;
}
protected Void doInBackground(Void... arg0) {
Socket clientSocket = null;
try {
clientSocket = new Socket(AddressIP, Port);
ObjectOutputStream outObject = new ObjectOutputStream(
clientSocket.getOutputStream());
outObject.writeObject(sendUser);
//DataOutputStream daneWyjsciowe = new DataOutputStream(
//clientSocket.getOutputStream());
//daneWyjsciowe.writeUTF("Czesc!" );
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
//response = "UnknownHostException: " + e.toString();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
//response = "IOException: " + e.toString();
} finally {
if (clientSocket != null) {
try {
clientSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return null;
}
Custom class (Te.class):
public class Te implements Serializable {
public String message;
public Te(String m){
message=m;
}
}
When I passing simple data i.e. String there is no problem. But now I want to pass object, but there is always ClassNotFoundException at server. I read lot of stacks but I didnt find answer. Could U help me?

how to Receive UDP packets, when it comes from server? for android java

I have used a thread for UDP receive packet. When I am sending a packet to that particular IP, where the UDP receive program runs. The application will be stopped unfortunately. Then if I remove the thread called new Thread(new Runnable()) and public void run the application will run good, but only one data has received. My intention is to receive data at the receiver end continuously, when data comes. please acknowledge me.
udpserver.java:
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
public class UdpServer extends Activity {
/** Called when the activity is first created. */
private TextView data;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
data = (TextView) findViewById(R.id.textView);
runUdpServer();
}
private static final int UDP_SERVER_PORT = 11111;
private static final int MAX_UDP_DATAGRAM_LEN = 1500;
private void runUdpServer() {
new Thread(new Runnable() {
public void run() {
String lText;
byte[] lMsg = new byte[MAX_UDP_DATAGRAM_LEN];
DatagramPacket dp = new DatagramPacket(lMsg, lMsg.length);
DatagramSocket ds=null;
try {
ds = new DatagramSocket(UDP_SERVER_PORT);
//disable timeout for testing
//ds.setSoTimeout(100000);
ds.receive(dp);
lText = new String(dp.getData());
Log.i("UDP packet received", lText);
data.setText(lText);
} catch (SocketException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
finally {
if (ds != null) {
ds.close();
}
}
}
}).start();
}

This is a working snippet I am using to receive and parse UDP packets.
try {
int port = 11000;
DatagramSocket dsocket = new DatagramSocket(port);
byte[] buffer = new byte[2048];
DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
while (true) {
dsocket.receive(packet);
lText = new String(buffer, 0, packet.getLength());
Log.i("UDP packet received", lText);
data.setText(lText);
packet.setLength(buffer.length);
}
} catch (Exception e) {
System.err.println(e);
e.printStackTrace();
}

You can setup a loop to read data from the udp socket.
try {
ds = new DatagramSocket(UDP_SERVER_PORT);
//disable timeout for testing
//ds.setSoTimeout(100000);
while (!ds.isClosed()) {
ds.receive(dp);
lText += new String(dp.getData());
Log.i("UDP packet received", new String(dp.getData());
runOnUiThread(new Runnable() {
public void run() {
data.setText(lText);
}
});
}
} catch (SocketException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (ds != null) {
ds.close();
}
}
UPDATE: since the packet data is received in non-UI thread. Direct access to data.setText(lText) in worker thread is invalid.

Send data and get Answer example:
new Thread(()->{
String message = "Hello Madam Coco";
byte[] msgbyte = message.getBytes(StandardCharsets.UTF_8);
int port = 12345;
String ip = "123,123,123,123";
try {
byte[] receviebyte = new byte[1024];
DatagramSocket socket = new DatagramSocket();
InetAddress address = InetAddress.getByName(ip);
DatagramPacket sendPack = new DatagramPacket(msgbyte, msgbyte.length, address, port);
socket.send(sendPack);
DatagramPacket receviePack = new DatagramPacket(receviebyte, receviebyte.length);
while (true) {
socket.receive(receviePack);
String receivestr = new String(receviebyte, receviePack.getOffset(), receviePack.getLength());
System.out.println("GETTEXT " + receivestr);
}
} catch (IOException e) {
e.printStackTrace();
}
}).start();

try {
DatagramSocket clientsocket=new DatagramSocket(9876);
byte[] receivedata = new byte[1024];
while(true)
{
DatagramPacket recv_packet = new DatagramPacket(receivedata, receivedata.length);
Log.d("UDP", "S: Receiving...");
clientsocket.receive(recv_packet);
String rec_str = new String(recv_packet.getData());
tv.setText(rec_str);
Log.d(" Received String ",rec_str);
InetAddress ipaddress = recv_packet.getAddress();
int port = recv_packet.getPort();
Log.d("IPAddress : ",ipaddress.toString());
Log.d(" Port : ",Integer.toString(port));
}
} catch (Exception e) {
Log.e("UDP", "S: Error", e);
}

is.readUTF() not recieving message

For the chat program in android side I am sending message via DataInput stream as
Socket sck = new Socket();
sck.connect(new InetAddress("192.168.1.91",1500),2000);
if(sck.isConnected())
{
DataOutputStream os = new DataOutputStream(sck.getOutputStream());
os.writeUTf(msg);
System.out.println("Message sent");
}
and on the Server side My code is
ServerSocket serv = new ServerSocket(1500);
Socket sock = serv.accept();
DataInputStream is = new DataInputStream(sock.getInputStream);
String ans = is.readUTF();
System.out.println("Got"+ans);
But on server side it seems it does not received anything and still waiting for the message. But on client side It shows message sent.
Here is my full code.
package in.prasilabs.eagleeye;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.UnknownHostException;
public class EagleClient extends Thread
{
public int ret = 0;
private String ip;
private int port;
private Socket sck;
private boolean estb = false;
private DataInputStream is;
private DataOutputStream os;
private String rmsg = null;
private String msg;
private String username;
private String password;
public String reply;
Data dt = new Data();
public EagleClient()
{
}
public EagleClient(String ip, int port, String username, String password)
{
this.ip = ip;
this.port = port;
this.username = username;
this.password = password;
}
public void run()
{
establish();
if(estb == true)
{
sendInfo(username,password);
}
}
public void establish()
{
int time_out = 2000;
try
{
System.out.println("trying to connect");
sck = new Socket();
sck.connect(new InetSocketAddress(dt.getIp(),dt.getServerPort()),time_out);
estb = true;
System.out.println("Established");
}
catch (UnknownHostException e)
{
ret =0;
e.printStackTrace();
}
catch (IOException e)
{
ret = 0;
// TODO Auto-generated catch block
e.printStackTrace();
}
if(estb == true)
{
try {
is = new DataInputStream(sck.getInputStream());
os = new DataOutputStream(sck.getOutputStream());
dt.setOS(os);
dt.setIS(is);
System.out.println("Messages are ready to send");
} catch (IOException e)
{
ret = 0;
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void sendInfo(String user,String password)
{
Data dt = new Data();
is = dt.getIS();
os = dt.getOS();
String drport = Integer.toString(dt.getdrPort());
try {
os.writeUTF("logn");
System.out.println("Sending user info");
os.writeUTF(dt.getUsername());
os.writeUTF(dt.getPassword());
os.writeUTF(drport);
reply = is.readUTF();
if(reply.equals("success"))
dt.setLoginStatus(true);
else
dt.setLoginStatus(false);
System.out.println("ACk recieved");
} catch (IOException e) {
ret = 0;
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public int sendMessage(String msg)
{
Data dt = new Data();
os = dt.getOS();
is = dt.getIS();
this.msg = msg;
try {
os.writeUTF(msg);
System.out.println("Client :" +msg);
recieveMessage();
} catch (IOException e) {
ret = 0;
// TODO Auto-generated catch block
e.printStackTrace();
}
return ret;
}
public void recieveMessage()
{
try {
System.out.println("Trying to get acknowledgement");
sck.setSoTimeout(2000);
rmsg = is.readUTF();
if(rmsg.equals(msg))
{
System.out.println("Ack recvd" +rmsg);
ret = 1;
}
else if(!msg.equalsIgnoreCase(rmsg))
{
//sendMessage();
Thread.sleep(100);
System.out.println("Retrying");
rmsg = is.readUTF();
System.out.println("Ack recvd" +rmsg);
ret = 1;
}
else
{
System.out.println("Message not recieved");
ret = 0;
}
} catch (IOException e) {
ret = 0;
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InterruptedException e){
e.printStackTrace();
}
}
}

Try to use something like this:
String message = "";
while (!"end".equals(message)) {
if (is.available() != 0) {
message = dis.readUTF();
System.out.println(message);
}
}
I checked this - working. Server must be up before client will send message.

Android sends UDP packets to a Java client over WiFi

I'm creating 2 programs which one of them sends UDP packets from an Adnroid device and a second one (Java) receives them. So it works good if I use WiFi-router. But if I use a direct connection the Java application doesn't receive these packets. Under the direct connection I mean creating HOTSPOT on computer and connecting to it by the Android device. I used code snippet bellow:
Server's code:
public class UDPServer {
InetAddress groupAddress;
DatagramPacket packet;
byte[] buffer;
DatagramSocket socket;
static String ip = "227.0.25.57";
static int port = 6789;
private boolean isRun = false;
private String message = "";
private int broadcastInterval;
public void StopBroadcasting(){
isRun = false;
}
public void StartBroadcasting(String message, int broadcastInterval){
isRun = true;
this.message = message;
this.broadcastInterval = broadcastInterval;
new Thread(runner).start();
}
Runnable runner = new Runnable() {
#Override
public void run() {
while(isRun){
try {
SendBroadcastMessage(message);
System.out.println("msg sended...");
Thread.sleep(broadcastInterval);
} catch (InterruptedException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
System.out.println("Stopping UDPServer...");
}
};
public UDPServer() {
buffer = new byte[4096];
try {
groupAddress = InetAddress.getByName(ip);
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
socket = new DatagramSocket();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void SendBroadcastMessage(String msg) throws IOException{
if(msg==null) return;
buffer = msg.getBytes();
packet = new //DatagramPacket(buffer, buffer.length);
DatagramPacket(buffer, buffer.length, groupAddress, port);
socket.send(packet);
}
public static void Send(String msg){
try {
InetAddress group = InetAddress.getByName(ip);
MulticastSocket s = new MulticastSocket(port);
s.joinGroup(group);
DatagramPacket hi = new DatagramPacket(msg.getBytes(), msg.length(),
group, port);
s.send(hi);
System.out.println("send...");
} catch (SocketException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}}
Client's code:
public class UDPClient {}
MulticastSocket socket;
InetAddress groupAddress;
DatagramPacket packet;
byte[] buffer;
static String ip = "227.0.25.57";
static int port = 6789;
public interface OnReceiveDataListener{
public abstract void onReceiveData(String data);
}
private OnReceiveDataListener ReceiveDataListener = null;
public void setReceiveDataListener(OnReceiveDataListener ReceiveDataListener) {
this.ReceiveDataListener = ReceiveDataListener;
}
public OnReceiveDataListener getReceiveDataListener() {
return ReceiveDataListener;
}
private boolean isRun = false;
private Thread broadcastReceiver;
public void StopBroadcasting(){
isRun = false;
if(broadcastReceiver!=null)
broadcastReceiver.interrupt();
}
public void StartBroadcasting(){
isRun = true;
broadcastReceiver = new Thread(runner);
broadcastReceiver.start();
}
Runnable runner = new Runnable() {
#Override
public void run() {
while(isRun){
try {
String msg = ReceiveBroadcastMessage();
if(ReceiveDataListener!=null)
ReceiveDataListener.onReceiveData(msg);
} catch (IOException e) {
e.printStackTrace();
}
}
}
};
public UDPClient(){
buffer = new byte[4096];
try {
groupAddress = InetAddress.getByName(ip);
socket = new MulticastSocket(port);
socket.joinGroup(groupAddress);
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public String ReceiveBroadcastMessage() throws IOException{
packet = new DatagramPacket(buffer, buffer.length);
System.out.println("before receive");
socket.receive(packet);
System.out.println(packet.getData());
return new String(packet.getData());
}
public void DeInit(){
try {
socket.leaveGroup(groupAddress);
} catch (IOException e) {
e.printStackTrace();
}
socket.close();
}
MulticastSocket msocket;
public static void Receive(){
MulticastSocket msocket;
try {
msocket = new MulticastSocket(port);
InetAddress group = InetAddress.getByName(ip);
msocket.joinGroup(group);
byte[] inbuf = new byte[1024];
DatagramPacket packet = new DatagramPacket(inbuf, inbuf.length);
System.out.println("before receive");
msocket.receive(packet);
System.out.println("after receive");
int numBytesReceived = packet.getLength();
System.out.println(new String(packet.getData()));
msocket.leaveGroup(group);
msocket.close();
System.out.println(numBytesReceived);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}}
If you could see I have 2 methods of sending and receiving packets. The both don't work! What do I wrong?
Help me please.

I've found solution:
http://code.google.com/p/boxeeremote/wiki/AndroidUDP