Good day.Im trying to connect to server with socket.Here is my code on how i do it.
private class SocketConnection extends AsyncTask<String, String, String> {
PrintWriter out;
BufferedReader in;
#Override
protected String doInBackground(String... params) {
connect();
try {
out = new PrintWriter(clientSocket.getOutputStream());
in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
} catch (IOException ex) {
System.out.append("error").append("socketcoonection").println();
}
String msg = null;
try {
msg = in.readLine();
} catch (IOException e) {
e.printStackTrace();
}
while (run) {
System.out.append(msg).append("socketcoonection").println();
out.println();
out.flush();
/*try {
msg = in.readLine();
} catch (IOException ex) {
Logger.getLogger(MainActivity.class.getName()).log(Level.SEVERE, null, ex);
}*/
}
return null;
}
}
and here is the connect() method
public void connect() {
try {
clientSocket = new Socket("vaenterprises.org/test.php", 8080);
} catch (UnknownHostException ex) {
} catch (IOException ex) {
}
if (clientSocket != null) {
run = true;
}
}
and this is the server side php code of test.php
echo json_encode("socket working");
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
and the address link is vaenterprises.org/test/php so im trying to connect to it and read the input or output stream or the echo.Whatever i do,i get nullPointerException at System.out.append(msg).append("socketcoonection").println(); and during debug i figured out that its socket which is null...Please tell me what am i doing wrong?
Related
I have writing some driven tests to a flutter project and there are a barcode scanner functionality which I can test successfully using the virtual scene tool provided by android emulator.
However there are many cases to test regarding to different barcodes. I want to set a specific barcode image on virtual scene to each case. Is it possible?
I found that the value of this image is putted on ~/.android/avd/[emulatorName]/AVD.conf file at virtualscene\posters variable.
virtualscene\posters=#Variant(\0\0\0\b\0\0\0\x2\0\0\0\b\0w\0\x61\0l\0l\0\0\0\n\xff\xff\xff\xff\0\0\0\n\0t\0\x61\0\x62\0l\0\x65\0\0\0\n\xff\xff\xff\xff)
virtualscene\posters=#Variant(\0\0\0\b\0\0\0\x2\0\0\0\b\0w\0\x61\0l\0l\0\0\0\n\ 0\0\0\\\0/\0U\0s\0\x65\0r\0s\0/\0l\0\x65\0o\0n\0\x61\0r\0\x64\0o\0.\0\x61\0r\0m\0\x65\0r\0o\0/\0\x44\0\x65\0s\0k\0t\0o\0p\0/\0J\0\x61\0m\0\x65\0s\0W\0i\0l\0s\0o\0n\0.\0p\0n\0g\0\0\0\n\0t\0\x61\0\x62\0l\0\x65\0\0\0\n\xff\xff\xff\xff)
You can replace the default (global) image located at $ANDROID_SDK_HOME/emulator/resources/poster.png with your poster.png image,
nor change the default pointer by editing the file $ANDROID_SDK_HOME/emulator/resources/Toren1BD.posters.
You can set the virtual scene image to a specified path. And manipulate the target image while testing.
As the Instrumented tests are running on your (virtual) device, it cannot manipulate the host machine files directly. What can be done, (which is an ugly hack) is to start a server on the host, which can be reached from the virtual device with the hosts loop-back "10.0.2.2" address.
This server can manipulate the target files.
If anybody has better solution, please share it!
An example server and client is here.
Server:
import java.io.*;
import java.net.*;
import java.nio.channels.FileChannel;
public class FileManipulatorServer {
public static void main(String args[]) {
int port = 6789;
FileManipulatorServer server = new FileManipulatorServer( port );
server.startServer();
}
// declare a server socket and a client socket for the server
private ServerSocket fileManipulatorServer = null;
private Socket clientSocket = null;
private int port;
public FileManipulatorServer(int port ) {
this.port = port;
}
public void stopServer() {
System.out.println( "Server cleaning up." );
System.exit(0);
}
public void startServer() {
// Try to open a server socket on the given port
// Note that we can't choose a port less than 1024 if we are not
// privileged users (root)
try {
fileManipulatorServer = new ServerSocket(port);
}
catch (IOException e) {
System.out.println(e);
}
System.out.println( "Waiting for connections. Only one connection is allowed." );
// Create a socket object from the ServerSocket to listen and accept connections.
// Use FileManipulatorTask to process the connection.
while ( true ) {
try {
clientSocket = fileManipulatorServer.accept();
FileManipulatorTask task = new FileManipulatorTask(clientSocket, this);
task.run();
}
catch (IOException e) {
System.out.println(e);
}
}
}
}
class FileManipulatorTask {
private BufferedReader is;
private PrintStream os;
private Socket clientSocket;
private FileManipulatorServer server;
public FileManipulatorTask(Socket clientSocket, FileManipulatorServer server) {
this.clientSocket = clientSocket;
this.server = server;
System.out.println( "Connection established with: " + clientSocket );
try {
is = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
os = new PrintStream(clientSocket.getOutputStream());
} catch (IOException e) {
System.out.println(e);
}
}
public void run() {
String line;
try {
boolean serverStop = false;
line = is.readLine();
System.out.println( "Received " + line );
saveImageToPoster(line.trim());
os.println("OK");
os.flush();
System.out.println( "Connection closed." );
is.close();
os.close();
clientSocket.close();
if ( serverStop ) server.stopServer();
} catch (IOException e) {
System.out.println(e);
}
}
private void saveImageToPoster(String filename) {
try {
FileChannel src = new FileInputStream("C:\\fullpathtopostercandidates\\"+filename).getChannel();
FileChannel dest = new FileOutputStream("C:\\fullpathtoconfiguredposter\\poster.jpg").getChannel();
dest.transferFrom(src, 0, src.size());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Client:
import java.io.*;
import java.net.*;
public class FileNameSenderClient {
private String hostname = "10.0.2.2";
private int port = 6789;
public void sendFileName(String filename) {
Socket clientSocket = null;
DataOutputStream os = null;
BufferedReader is = null;
try {
clientSocket = new Socket(hostname, port);
os = new DataOutputStream(clientSocket.getOutputStream());
is = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
} catch (UnknownHostException e) {
System.err.println("Don't know about host: " + hostname);
} catch (IOException e) {
System.err.println("Couldn't get I/O for the connection to: " + hostname);
}
if (clientSocket == null || os == null || is == null) {
System.err.println( "Something is wrong. One variable is null." );
return;
}
try {
System.out.println("Write to output stream");
os.writeBytes( filename +"\n");
os.flush();
String responseLine = is.readLine();
System.out.println("Server returns: " + responseLine);
os.close();
is.close();
clientSocket.close();
} catch (UnknownHostException e) {
System.err.println("Trying to connect to unknown host: " + e);
} catch (IOException e) {
System.err.println("IOException: " + e);
}
}
}
Use the FileNameSenderClient from your instrumented test like this.
#Test
public void testQRcodeReadingOK()
{
FileNameSenderClient c = new FileNameSenderClient();
c.sendFileName("QRCode.jpg");
//your code that wants to use the image, like the this:
onView(withId(R.id.load_qr_code)).perform(click());
}
I tested many ways and finally asked this question. as many of articles mentioned in wifi-direct all clients know group owner's IP and can use this ip to send a message and group owner will save clients ip address. but I can't send a message from group owner to client like that client sent first time. I faced with this error's:
first:
failed to connect to /192.168.49.24 (port 8988) after 5000ms: isConnected failed:
EHOSTUNREACH (No route to host).
after change code:
first error + bind failed: EADDRINUSE (Address already in use).
My AsyncTask to retrieve :
#Override
protected String doInBackground(Void... params) {
ServerSocket serverSocket = null;
Socket client = null;
DataInputStream inputstream = null;
try {
serverSocket = new ServerSocket(8988);
client = serverSocket.accept();
inputstream = new DataInputStream(client.getInputStream());
String str = inputstream.readUTF();
String IP = client.getInetAddress().toString();
serverSocket.close();
return IP+"+"+str;
} catch (IOException e) {
Log.e(WiFiDirectActivity.TAG, e.getMessage());
return null;
}finally{
if(inputstream != null){
try{
inputstream.close();
} catch (IOException e) {
Log.e(WiFiDirectActivity.TAG, e.getMessage());
}
}
if(client != null){
try{
client.close();
} catch (IOException e) {
Log.e(WiFiDirectActivity.TAG, e.getMessage());
}
}
if(serverSocket != null){
try{
serverSocket.close();
} catch (IOException e) {
Log.e(WiFiDirectActivity.TAG, e.getMessage());
}
}
}
}
and my IntentService to send messages:
#Override
protected void onHandleIntent(Intent intent) {
Context context = getApplicationContext();
if (intent.getAction().equals(ACTION_SEND_IP)) {
String host = intent.getExtras().getString(EXTRAS_GROUP_OWNER_ADDRESS);
Log.e("DAVUD","Host:"+ host);
Socket socket = new Socket();
int port = intent.getExtras().getInt(EXTRAS_GROUP_OWNER_PORT);
Log.e("DAVUD","Port:"+ port);
DataOutputStream stream = null;
try {
socket.connect((new InetSocketAddress(host, port)), SOCKET_TIMEOUT);
stream = new DataOutputStream(socket.getOutputStream());
String str = intent.getStringExtra("message");
stream.writeUTF(str);
} catch (IOException e) {
Log.e(WiFiDirectActivity.TAG, e.getMessage());
} finally {
if (stream != null) {
try {
stream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (socket != null) {
if (socket.isConnected()) {
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
}
and some other codes I tested... There is another question asked same this but not answered(android-wifi-direct-how-to-send-data-from-group-owner-to-the-clients) this project based on wifiDirectDemo Simple. Please help I really need it.
After one year I sew my question again. the problem was not about wifi or connection. it's about string parsing. where a line in doInBackground is:
return IP+"+"+str
and in onPostExecute I parsed and get ip from returned string; but parse code was not correct. so returns:
192.168.49.24
instead of:
192.168.49.241
where two of them is valid ips I am not thought parse logic had problem. I changed code and used String[] instead of String.
I am trying to implement a simple socket that sends and receives strings from a server.
The following code is freezing the application, not sure if I have done something obviously wrong?
public String internetRoutesRetrieve(String userName) {
String command = null;
String response = null;
Socket socket = null;
DataOutputStream dataOutputStream = null;
DataInputStream dataInputStream = null;
try {
socket = new Socket("Hidden IP", HiddenPort);
dataOutputStream = new DataOutputStream(socket.getOutputStream());
dataInputStream = new DataInputStream(socket.getInputStream());
command = "SEARCH <" + userName + ">";
dataOutputStream.writeUTF(command);
response = dataInputStream.readUTF();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
finally {
if (socket != null) {
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (dataOutputStream != null) {
try {
dataOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (dataInputStream != null) {
try {
dataInputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return response;
}
Thanks
Edit: It seems the program is freezing when I am trying to save the response from the server
see AsyncTask for proper client server communication on Android application.
you'd usualy get android.os.NetworkOnMainThreadException if you don't but I'd give it a try.
I'm making an app that sends a string to a server over a socket and then reads the output after the server has processed that data. It worked perfectly when it was my foreground task, but I have since used AsyncTask to show a process dialog while the socket communication runs in the background, and things start breaking after I read the output from the server and then try to close the socket.
private class Progressor extends AsyncTask<String, Void, Void> {
ProgressDialog dialog;
protected void onPreExecute() {
dialog = ProgressDialog.show(ClearTalkInputActivity.this, "Loading..", "Analyzing Text", true, false);
}
protected Void doInBackground(String... strings) {
String language = strings[0].toLowerCase();
String the_text = strings[1];
Socket socket = null;
DataOutputStream dos = null;
DataInputStream dis = null;
try {
socket = new Socket(my_ip, port);
dos = new DataOutputStream(socket.getOutputStream());
dis = new DataInputStream(socket.getInputStream());
dos.writeUTF(language+"****"+the_text);
String in = "";
while (in.indexOf("</content>") < 0) {
in += dis.readUTF();
}
socket.close();
save_str(OUTPUT_KEY, in);
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
finally {
if (socket != null) {
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
if (dos != null) {
try {
dos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (dis != null) {
try {
dis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
protected void onPostExecute() {
if (dialog.isShowing())
dialog.dismiss();
startActivity(new Intent (output_intent));
}
}
The recommended way in Android is to use one of the two included HttpClients:
Apache HTTP Client
HttpURLConnection
There is no need to use sockets directly. These clients do a lot to improve your experience.
Here is a blog article by the Android developers, that explain the basics: http://android-developers.blogspot.de/2011/09/androids-http-clients.html
I have a BufferedReader, when I try to read it, it just hangs and doesn't do anything, am I doing this right? I am using this in an AsyncTask.
Edit: I have a tablet connected to the Wi-Fi, this connects to my computer which is broadcasting on 172.20.104.203 on port 5334, I can see when the thread starts, but nothing after that.
Here my code:
try {
final BufferedReader in = new BufferedReader(
new InputStreamReader(socket.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
final String msg;
msg = (line);
Log.d("DeviceActivity", msg);
}
} catch (Exception e) {
e.printStackTrace();
Log.e("ClientAcivtity: Exception",
String.valueOf(e));
}
EDIT
I have all the right permissions or anything, I was doing this outside a AsyncTask and it worked perfectly, moved it because I didn't want it in the main thread.
-Edit , here is the full code.
public class NetworkTask extends AsyncTask<Void, byte[], Boolean> {
Socket nsocket; // Network Socket
InputStream nis; // Network Input Stream
OutputStream nos; // Network Output Stream
private Handler handler = new Handler();
Boolean connected = false;
public static final int PORT = 5334;
public String SERVERIP = "172.20.104.203";
Socket socket;
#Override
protected void onPreExecute() {
Log.i("AsyncTask", "onPreExecute");
InetAddress serverAddr;
try {
serverAddr = InetAddress.getByName(SERVERIP);
socket = new Socket(serverAddr, PORT);
connected = true;
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("ClientAcivtity: Exception", String.valueOf(e));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("ClientAcivtity: Exception", String.valueOf(e));
}
}
#Override
protected Boolean doInBackground(Void... params) { // This runs on a
// different thread
boolean result = false;
try {
Log.d("ClientActivity", "C: Connecting...");
if (socket != null) {
int cont = 1;
while (cont == 1) {
try {
Log.d("ClientActivity", "C: Sending command.");
PrintWriter out = new PrintWriter(
new BufferedWriter(new OutputStreamWriter(
socket.getOutputStream())), true);
// where you issue the commands
out.println("getPos");
Log.d("ClientActivity", "C: Sent " + "getPos");
} catch (Exception e) {
Log.e("ClientAcivtity: Exception",
String.valueOf(e));
}
try {
final BufferedReader in = new BufferedReader(
new InputStreamReader(
socket.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
final String msg;
msg = (line);
Log.d("DeviceActivity", msg);
}
} catch (Exception e) {
e.printStackTrace();
Log.e("ClientAcivtity: Exception",
String.valueOf(e));
}
cont--;
}
Log.d("ClientActivity", "C: Closed.");
}
} catch (Exception e) {
Log.e("ClientAcivtity: Exception", String.valueOf(e));
}
return result;
}
#Override
protected void onProgressUpdate(byte[]... values) {
if (values.length > 0) {
Log.i("AsyncTask", "onProgressUpdate: " + values[0].length
+ " bytes received.");
}
}
#Override
protected void onCancelled() {
Log.i("AsyncTask", "Cancelled.");
}
#Override
protected void onPostExecute(Boolean result) {
if (socket != null) {
if (connected) {
if (result) {
Log.i("AsyncTask",
"onPostExecute: Completed with an Error.");
try {
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} else {
Log.i("AsyncTask", "onPostExecute: Completed.");
try {
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
}
}
My guess is that when you write out the command "getPos" the underlying BufferedWriter is not actually sending the data out on the line (you should verify this with tcpdump/wireshark). If this is the case, the server doesn't responsed to the readLine(), since it never got a command. To verify this claim, add out.flush(); after out.println("getPos");
Really, tcpdump will probably give you a better answer then anyone on the forums.
Also see http://developer.android.com/reference/java/io/BufferedWriter.html
Try doing it like this:
final BufferedReader in = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
StringBuffer buf = new StringBuffer();
int i;
while((i = in.read()) != -1){
buf.append((char) i);
}
String data = buf.toString();
Reading from sockets is a quite difficult issue depending where the socket is actually connected to and how the other side responds.
If the other side is extremely fast than it can provide the socket with enough data so that the read routines actually work fine. However if there is a delay in the other side of any kind (just needs to be slower than your read routine incl the small default timeout) then your read fails even though there might be data on the other side - just arriving a little too slow at the socket.
Depending on your needs you may wrap your own minimum and maximum timer around the read routine.
Please provide more information and we can better understand the issue.
In many cases it is necessary to have a minimum timeout large enough for the other side to push data to the socket - but you might also need a maximum time for how long you actually want to wait for data to arrive.
UPDATE:
first the runnable to start the monitoring thread. You may use monitoringCanRun in your loop to interrupt the thread if required. And monitoringThreadIsAlive can be used to know if the thread is still running.
monitoringCanRun = true;
new Thread(new Runnable() {
public void run() {
monitoringThreadIsAlive = true;
performMonitoring();
monitoringThreadIsAlive = false;
}
}).start();
}
and performMonitoring looks like:
public void performMonitoring() {
while (monitoringCanRun) {
... do your read in the while loop
...you might like to insert some delay before trying again...
try { //we delay every partial read so we are not too fast for the other side
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}