I am trying to read data continuously using the following code:
public class MyClientTask extends AsyncTask<Void, Void, Void> {
String dstAddress;
int dstPort;
String response = "";
MyClientTask(String addr, int port){
dstAddress = addr;
dstPort = port;
}
#Override
protected Void doInBackground(Void... arg0) {
Socket socket = null;
try {
socket = new Socket(dstAddress, dstPort);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(1024);
byte[] buffer = new byte[1024];
int bytesRead;
InputStream inputStream = socket.getInputStream();
while ((bytesRead = inputStream.read(buffer)) != -1){
readInpt = inputStream.toString();
byteArrayOutputStream.write(buffer, 0, bytesRead);
response = byteArrayOutputStream.toString("UTF-8");
}
textResponse.setText(readInpt);
} 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(socket != null){
try {
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return null;
}
#Override
protected void onPostExecute(Void result) {
textResponse.setText(response);
super.onPostExecute(result);
}
}
But for some reason, it doesn't show me any output in the textbox. any help would be appreciated.
There are at least two issues in your code.
Frist, I'm not sure the method toString() on the inputStream is going to work, because the documentation says it returns a description of the object (which would be different than the string recieved). You might be confusing this with the contents of buffer which might be what you really want.
readInpt = inputStream.toString(); // Probably wrong
Second. You're updating the User Interface from a background thread, inside doInBackground() , which is always forbidden.
textResponse.setText(readInpt); // Forbidden, move somewhere else, e.g. onPostExecute()
try {
socket = new Socket(dstAddress, dstPort);
BufferedReader stdIn = new BufferedReader(new InputStreamReader(socket.getInputStream()));
while (true) {
response = stdIn.readLine();
publishProgress(response);
Log.i("response", response);
}
} 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();
}
catch (Exception e) {
e.printStackTrace();
}
You cannot print it on text field because the socket will listen to the server socket.If server socket does not send any response it will listen to the socket continuously until the response is received.
Related
I am developing one Android Application in which I have to send location data on server and getting job data as a response in this way all communication is build but i am stuck of my mind on one thing when i trying to read the response from server the no any output and no any response is coming so please help me out of this stuck. Below is my code. Thanks in advance.
public static class MyClientTask extends AsyncTask<Void, Void, Void> {
String dstAddress;
int dstPort;
String response = "";
String s;
String red;
String loc;
String msg;
Socket socket = null;
DataOutputStream dataOutputStream = null;
DataInputStream dataInputStream = null;
InputStream is=null;
BufferedReader br=null;
public MyClientTask(String addr, int port,String msg){
dstAddress = addr;
dstPort = port;
loc=msg;
}
#Override
protected Void doInBackground(Void... arg0) {
try {
socket = new Socket(dstAddress, dstPort);
socket.setKeepAlive(true);
dataOutputStream = new DataOutputStream(socket.getOutputStream());
is=socket.getInputStream();
socket.setSoTimeout(60*1000);
dataInputStream = new DataInputStream(is);
Log.i("socket connect","socket OK");
dataOutputStream.writeUTF(loc);
while (dataInputStream == null)
{
////this part is not working
Log.i("DEV", "sleep "+is.available());
android.os.SystemClock.sleep(100);
}
br=new BufferedReader(new InputStreamReader(dataInputStream));
String st = null;
while(socket.isConnected()){
st = br.readLine();
}
Log.w("server response", "says Server = " + st);
Dbase db2=new Dbase(mcontext);
db2.addresponse(new info(st));
Log.w("second time server response", "says 2ndTime Server = " + st);
} catch (UnknownHostException e) {
Log.e("at exception", "at thread unknownHost " + e.getMessage());
e.printStackTrace();
} catch (IOException e) {
Log.e("io exception", "at thread IO " + e.getMessage());
e.printStackTrace();
}
finally{
Log.i("on finally block", "finally");
if (dataOutputStream != null){
try {
dataOutputStream.close();
} catch (IOException e) {
Log.e("io eception", "at thread dataoutput IO " + e.getMessage());
e.printStackTrace();
}
}
if (dataInputStream != null){
try {
dataInputStream.close();
} catch (IOException e) {
Log.e("data input exception", "at thread datainput IO " + e.getMessage());
e.printStackTrace();
}
}
if (socket != null){
try {
Log.i("socket", "socket closed");
socket.close();
} catch (IOException e) {
Log.e("socket exception", "at thread finally IO " + e.getMessage());
e.printStackTrace();
}
}
}
return null;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
//displayProgressBar("Downloading...");
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
}
}
You use InputStream.available method incorrectly. This method will not try to retrieve data. Actually most implementations of this method always return 0. See Inputstream available reference.
I recommend you just remove available checks and let readLine block as needed. The same goes for BufferedReader.ready - generally this does not show that you will get any data when attempting to read so this call is also not useful.
Android send data to pc - client side (work with success):
Button send = (Button) findViewById(R.id.sendSocket);
send.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try{
Socket socket = new Socket("IP",8000);
DataOutputStream DOS = new DataOutputStream(socket.getOutputStream());
DOS.writeUTF("Hello");
socket.close();
}catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
Now How can i keep listening to receive data from pc (server side) ???
that's what i am tryng (not working) :
try {
Boolean end = false;
ServerSocket ss = new ServerSocket(8000);
while(!end){
//Server is waiting for client here, if needed
Socket s = ss.accept();
BufferedReader input = new BufferedReader(new InputStreamReader(s.getInputStream()));
PrintWriter output = new PrintWriter(s.getOutputStream(),true); //Autoflush
String st = input.readLine();
recive.setText(st);
s.close();
//if ( STOPPING conditions){ end = true; }
}
ss.close();
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
recive.setText(e.toString());
}
try something like this :
ServerSocket ss = new ServerSocket(8000);
Socket s = ss.accept();
BufferedReader input = new BufferedReader (new InputStreamReader (s.getInputStream ()));
while (true)
{
String st = "";
try
{
st = input.readLine ();
System.out.println (st);
}
catch (IOException e)
{
//error ("System: " + "Connection to server lost!");
System.exit (1);
break;
}
}
ss.close();
I'm having a weird problem. I'm creating a socket and giving it the IP 192.168.43.255. When I use InetAddress.getByName(IP) it adds / to the ip as shown in the log below. Why this is happening ??
here is my code
public class ServerCom extends AsyncTask<String, Void , String>{
private int port=9999;
private String IP="192.168.43.255";
private BufferedReader input;
private Socket socket;
private DataOutputStream toSer;
private InetAddress serverAddr;
private String LocationID;
File file;FileWriter writer;
#Override
protected String doInBackground(String... RSS) {
// TODO Auto-generated method stub
Log.d("s","async");
SandboxView.Locate=false;
try {
serverAddr = InetAddress.getByName(IP);
socket = new Socket(serverAddr, port);
toSer = new DataOutputStream(socket.getOutputStream());
input = new BufferedReader(new InputStreamReader(socket.getInputStream()));
} catch (UnknownHostException e2) {
// TODO Auto-generated catch block
e2.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// send result to server
try {
toSer.writeBytes(RSS[0]+"\n");
//get the response from server
LocationID=input.readLine();
toSer.close();
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return LocationID;
}
protected void onPostExecute(String result)
{
super.onPostExecute(result);
//dismiss progressdialog.
//update ui
MainActivity.LocationID=LocationID;
SandboxView.Localization=MainActivity.CH2.getLocation(LocationID);
try {
writer = new FileWriter(file, true);
writer.append("room :"+LocationID+"\n");
writer.append(SandboxView.Localization.x+" "+SandboxView.Localization.y+"\n");
writer.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
MainActivity.view.invalidate();
SandboxView.Locate=true;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
}
05-16 17:53:16.331: W/System.err(3495): java.net.ConnectException: /192.168.43.255:9999 - Network is unreachable
This isn't really adding a / to the IP address, but the format of the address output by InetAddress.toString() uses a / to separate the hostname from the host address. See here. So, the / isn't really being added to the address, it is just shown in the logging.
I am trying to save every output data in asynctask for each http call.But I am unable to see any data in a file.I really appreciate any help.Thanks in Advance.
final String[] ar={"1","2","3",.............,"25"}
filename="test_file";
myFile = new File("/sdcard/"+filename);
try {
myFile.createNewFile();
fOut = new FileOutputStream(myFile);
} catch (FileNotFoundException e1) {
e1.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
myOutWriter = new OutputStreamWriter(fOut);
for ( j = 0; j < ar.length; j++) {
u="http://www.example.com/"+ar[j];
JSONParser jParser=new JSONParser();
new MyAsyncTask().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,u);
}
try {
myOutWriter.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
class MyAsyncTask extends AsyncTask<String, String, Void> {
private ProgressDialog progressDialog = new ProgressDialog(MainActivity.this);
InputStream inputStream = null;
String result = "";
protected void onPreExecute() {
progressDialog.setMessage("Downloading your data...");
progressDialog.show();
progressDialog.setOnCancelListener(new OnCancelListener() {
public void onCancel(DialogInterface arg0) {
MyAsyncTask.this.cancel(true);
}
});
}
#Override
protected Void doInBackground(String... params) {
String url_select = params[0];
try {
HttpClient httpclient = new DefaultHttpClient();
HttpResponse httpResponse = httpclient.execute(new HttpGet(url_select));
// receive response as inputStream
inputStream = httpResponse.getEntity().getContent();
//
// // Read content & Log
// inputStream = httpEntity.getContent();
} catch (UnsupportedEncodingException e1) {
Log.e("UnsupportedEncodingException", e1.toString());
e1.printStackTrace();
} catch (ClientProtocolException e2) {
Log.e("ClientProtocolException", e2.toString());
e2.printStackTrace();
} catch (IllegalStateException e3) {
Log.e("IllegalStateException", e3.toString());
e3.printStackTrace();
} catch (IOException e4) {
Log.e("IOException", e4.toString());
e4.printStackTrace();
}
// Convert response to string using String Builder
try {
BufferedReader bReader = new BufferedReader(new InputStreamReader(inputStream, "iso-8859-1"), 8);
StringBuilder sBuilder = new StringBuilder();
String line = null;
while ((line = bReader.readLine()) != null) {
sBuilder.append(line + "\n");
}
inputStream.close();
result = sBuilder.toString();
} catch (Exception e) {
Log.e("StringBuilding & BufferedReader", "Error converting result " + e.toString());
}
return null;
} // protected Void doInBackground(String... params)
protected void onPostExecute(Void v) {
//parse JSON data
try{
JSONObject jArray = new JSONObject(result);
String name = jArray.getString("name");
if (name!=null) {
Log.w("idname", name);
//
myOutWriter.append(name).append("\r\n");
//
Toast.makeText(getBaseContext(), name, 5).show();
}
// End Loop
this.progressDialog.dismiss();
} catch (JSONException e) {
Log.e("JSONException", "Error: " + e.toString());
} // catch (JSONException e)
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} // protected void onPostExecute(Void v)
} //class MyAsyncTask extends AsyncTask<String, String, Void>
for ( j = 0; j < ar.length; j++) {
u="http://www.example.com/"+ar[j];
JSONParser jParser=new JSONParser();
new MyAsyncTask().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,u);
}
try {
myOutWriter.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
You close the myOutWriter after start MyAsyncTask. So when MyAsyncTask try to write data to file, it throw OutputStreamWriter is closed exception.
You need remove the code of close myOutWriter from here. Add add close code at the end of onPostExecute like below:
void onPostExecute(Void v) {
.....
} catch (JSONException e) {
Log.e("JSONException", "Error: " + e.toString());
} // catch (JSONException e)
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int count = taskCount.decrementAndGet()
if(count == 0 ) {
try {
myOutWriter.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
} // protected void onPostExecute(Void v)
the definition of taskCount is like this:
AtomicInteger taskCount = new AtomicInteger(ar.length - 1);
At last, I think Thread and CountDownLatch is better option
check if entity not null then write to db
HttpEntity entity = response.getEntity();
if(entity!=null ){
inputStream = entity.getContent();
}
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();
}
}
}