try {
input = new BufferedReader(new InputStreamReader(
mSocket.getInputStream()));
while (!Thread.currentThread().isInterrupted()) {
String messageStr = null;
messageStr = input.readLine();
if (messageStr != null) {
updateMessages(messageStr, false);
} else {
break;
}
}
input.close();
} catch (IOException e) {
Log.e(CLIENT_TAG, "Server loop error: ", e);
}
I am using the above code in a thread for receiving responses from socket connection.
In Android it works correctly as I used out.println() for sending data, but when the device is connected to ios and starts to receive data it cannot identify the end and is only received when the connection is closed. Is there any alternative methods other than readLine() and how to use in the above code.
This would work better.
try
{
input = new BufferedReader(new InputStreamReader(mSocket.getInputStream()));
String messageStr = "";
while (!Thread.currentThread().isInterrupted() && (messageStr = input.readLine()) != null)
{
updateMessages(messageStr, false);
}
input.close();
} catch (Exception e) {
Log.e(CLIENT_TAG, "Server loop error: ", e);
}
Related
I am implementing a simple http server using Java ServerSocket, on Android 6.1 platform. By calling ServerSocket.accept(), the thread is blocking until request comes in.
The problem is, I always saw duplicate acceptances of the same http request, and eventually only one of them could get contents of the request. Any idea?
A simple http server using Java ServerSocket, on Android 6.1 platform
while (mServerSocket != null && !mServerSocket.isClosed()) {
try {
Log.i(TAG, "{\"msgid\":\"RunningServer\",\"msg\":\"LogHttpServer starts to listen at " + mServerSocket.getInetAddress().getHostAddress() + ":" + mServerSocket.getLocalPort() + "\"}");
Socket clientSocket = mServerSocket.accept();
Thread clientRequest = new WorkThread(clientSocket, appContext);
clientRequest.start();
} catch (Exception e) {
...
}
}
class WorkThread extends Thread {
#Override
public void run() {
Log.i(TAG, "{\"msgid\":\"ReceivingData\",\"msg\":\"LogHttpServer accepted connection from "+socket.getInetAddress().getHostAddress()+"\"}");
processHttpRequest(this.socket);
private void processHttpRequest(Socket socket) {
BufferedReader in = null;
OutputStream out = null;
if (this.socket.isConnected()) {
try {
in = new BufferedReader(new InputStreamReader(socket.getInputStream(), StandardCharsets.UTF_8));
} catch (IOException e) {
Log.e(TAG, "{\"msgid\":\"IOException\",\"msg\":\"fail to get Input Stream, " + e.toString() + "\"}");
}
try {
out = socket.getOutputStream();
} catch (IOException e) {
Log.e(TAG, "{\"msgid\":\"IOException\",\"msg\":\"fail to get Input Stream, " + e.toString() + "\"}");
}
int lineNum = 0;
String method = null;
String request = null;
while (true) {
String line;
try {
if ( in == null || (line = in.readLine()) == null || line.length() == 0) break;
lineNum++;
Log.i(TAG, "{\"msgid\":\"HttpRequest\",\"msg\":\"" + line + "\"}");
line = line.trim();
if (lineNum == 1) {
StringTokenizer tokenized = new StringTokenizer(line);
method = tokenized.hasMoreTokens() ? tokenized.nextToken().toUpperCase() : null;
request = tokenized.hasMoreTokens() ? tokenized.nextToken().toLowerCase() : null;
}
} catch (IOException e) {
Log.e(TAG, "{\"msgid\":\"IOException\",\"msg\":\"fail to read in Stream\"}");
} catch (Exception e) {
Log.e(TAG, "{\"msgid\":\"Exception\",\"msg\":\"" + e.toString() + "\"}");
return;
}
}
...
}
}
The resulting logs show as below:
2019-06-14T10:34:52.635Z 3149 3209 I LogHttpServer: {"msgid":"RunningServer","msg":"LogHttpServer starts to listen at :::33284"}
2019-06-14T10:34:52.636Z 3149 3209 I LogHttpServer: {"msgid":"RunningServer","msg":"LogHttpServer starts to listen at :::33284"}
2019-06-14T10:34:52.636Z 3149 4409 I LogHttpServer: {"msgid":"ReceivingData","msg":"LogHttpServer accepted connection from 192.168.43.254"}
--> this is where I don't expect: duplicate acceptance with separate thread created.
2019-06-14T10:34:52.636Z 3149 4410 I LogHttpServer: {"msgid":"ReceivingData","msg":"LogHttpServer accepted connection from 192.168.43.254"}
2019-06-14T10:34:52.642Z 3149 4409 I LogHttpServer: {"msgid":"HttpRequest","Method":"GET", "Request":"/cgi-bin/logs.sh"}
--> later, it actually not able to parse the contents
2019-06-14T10:35:03.216Z 3149 4410 E LogHttpServer: {"msgid":"InvalidHttpRequest","msg":"null Method or Request. Return."}
I made a client-server application where the server has to send a list of emails to the client, which after load that into a ListView gives the possibility, through a menuBar, to delete them. In the client all these operations are made in the Data Model (I followed the MVC pattern). This is the server:
class ThreadedEchoHandler implements Runnable {
private Socket incoming;
private String nomeAccount = "";
public void run() {
try {
incoming = s.accept();
} catch (IOException ex) {
System.out.println("Unable to accept requests");
}
contenutoTextArea.append("Connected from: " + incoming.getLocalAddress() + "\n");
textarea.setText(contenutoTextArea.toString());
try {
//PHASE 1: The server receives the email
try {
BufferedReader in = new BufferedReader(new InputStreamReader(incoming.getInputStream()));
nomeAccount = in.readLine();
} catch (IOException ex) {
System.out.println("Not works");
}
//PHASE 2: I'm getting all the emails from the files
File dir = new File("src/server/" + nomeAccount);
String[] tmp = new String[100];
int i = 0;
for (File file : dir.listFiles()) {
if (file.isFile() && !(file.getName().equals(".DS_Store"))) {
try (BufferedReader br = new BufferedReader(new FileReader(file))) {
String line;
while ((line = br.readLine()) != null) {
tmp[i++] = line;
}
} catch (IOException ex) {
System.out.println("Cannot read from file");
}
}
}
//PHASE 3: The server sends the ArrayList to the client
PrintWriter out = new PrintWriter(incoming.getOutputStream(), true);
for (int j = 0; j < i; j++) {
out.println(tmp[j]); // send the strings to the client
}
} catch (IOException ex) {
System.out.println("Cannot send the strings to the client");
}
//PHASE 4: Here I loop and wait for the client choise
BufferedReader in;
String op;
try {
in = new BufferedReader(new InputStreamReader(incoming.getInputStream()));
while ((op = in.readLine()) != null) {
if (op.equals("Elimina")) {
String tmp = in.readLine();
File file = new File("src/server/" + nomeAccount + "/" + tmp + ".txt");
file.delete();
} else if (op.equals("Invia")) {
//...
} else {
//...
}
}
} catch (IOException ex) {
System.out.println("Non so");
} finally {
try {
incoming.close();
} catch (IOException ex) {
System.out.println("Cannot closing the socket");
}
}
}
}
These are the methods of the client:
public void loadData() throws IOException, ClassNotFoundException, ParseException {
try {
s = new Socket("127.0.0.1", 5000);
ArrayList<Email> email = new ArrayList<Email>();
DateFormat format = new SimpleDateFormat("dd/MM/yyyy");
Date data;
/* PHASE 1: The client sends a string to the server */
//try {
PrintWriter out = new PrintWriter(s.getOutputStream(), true);
out.println(account); // send the account name to server
/* PHASE 2: The client receives the ArrayList with the emails */
BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
String line;
String message[] = new String[5];
for (int j=0; (line = in.readLine()) != null;) {
message[j++] = line;
if (j==5) {
data = format.parse(message[3]);
email.add(new Email((Integer.parseInt(message[0])), message[1], account, message[2], message[4], data));
j=0;
}
}
//Casting the arrayList
emailList = FXCollections.observableArrayList(email);
//Sorting the emails
Collections.sort(emailList, (Email o1, Email o2) -> {
if (o1.getData() == null || o2.getData() == null) {
return 0;
}
return o1.getData().compareTo(o2.getData());
});
/*} finally {
s.close();*/
//}
} catch (SocketException se) {
emailList.setAll(null, null);
}
}
public void deleteMail(Email da_elim) throws IOException {
int id_del = da_elim.getID();
emailList.remove(da_elim);
PrintWriter out = new PrintWriter(s.getOutputStream(), true);
out.println("Elimina");
out.println(id_del);
}
The PHASE 1, 2, 3 of the Server are for the upload of the emails, and work with the loadData() method. Without the PHASE 4 the program works. Now, if I write that loop, the GUI of the client doesn't load and I cannot press on the DELETE button (which should make the input to innescate something (in this the elimination of the file) into that loop. Why the client doesn't load even if they are two different threads? And why without that loop it works?
EDIT: with the Listener class implemented but still doesn't works
//PHASE 4: Here I loop and wait for the client choise
BufferedReader in;
String op;
try {
in = new BufferedReader(new InputStreamReader(incoming.getInputStream()));
/*while ((op = in.readLine()) != null) {
System.out.println("OP: " + op);
if (op.equals("Elimina")) {
String tmp = in.readLine();
contenutoTextArea.append("Ho eliminato la mail ").append(tmp).append(" \n");
textarea.setText(contenutoTextArea.toString());
File file = new File("src/server/" + nomeAccount + "/" + tmp + ".txt");
file.delete();
}
}*/
Listener lis = new Listener(in, new LinkedBlockingQueue<String>());
lis.run();
System.out.println("bbbbb");
} catch (IOException ex) {
System.out.println("Unable to read messages");
} finally {
try {
incoming.close();
} catch (IOException ex) {
System.out.println("Cannot close the socket");
}
}
I think you should run jvisualvm (it's a tool installed with jdk in /bin/ location of your jdk) and look for that Thread lifecycle you create on server. Also check if your Thread don't go through the code and just ends his life skipping waiting for client.
Is this Thread somehow connected with client? Because you cannot run client App. Are they separated? Another think that came to my mind is using
Platform.runLater(()->{
});
if your client GUI is in JavaFX. Use it if you are creating GUI, changing values in fields and anything you do on your GUI. Maybe your server is waiting for user response and after that GUI is built? Which causes that you can't press DELETE button.
I'm not currently able to comment, so I can't ask for clarification, but I think I'm correctly interpreting what's wrong. "The program hangs when it enters a loop that waits for input from two controllers". Assuming I got that part right, the most likely culprit would be that buffered reader is hanging indefinitely because its not receiving input. When I first ran into this issue, I threw it inside its own "receiver" class and used a Queue to bus over anything it received to a loop in my main class. my code looked something like this:
import java.io.BufferedReader;
import java.io.IOException;
import java.util.concurrent.BlockingQueue;
public class Listener implements Runnable
{
private BufferedReader br;
private BlockingQueue<String> q;
private boolean shouldClose = false;
public Listener(BufferedReader br, BlockingQueue<String> q)
{
this.q = q;
this.br = br;
}
public void run()
{
loop();
System.out.println("listener has stopped");
}
public void loop()
{
String line = "";
try
{
while((line = br.readLine()) != null && !shouldClose)
{
q.put(line);
}
}
catch (IOException | InterruptedException e)
{
e.printStackTrace();
}
}
public void shutdown()
{
shouldClose = true;
}
}
apologies if I've misunderstood in any way, or missed something in your code.
I'm trying to make a basic client <-> server connection in Java. When trying to write to the server, the client sends the details correctly, and the server stalls on reading it until the client output stream is closed. Though, once the output stream is closed it apparently closes the socket, and due to that the server can't reply to the client. Here's the main snippet of code that handles this interaction.
Client:
private void sendCmd(String cmd) {
String infoToSend = cmd;
try {
socket = new Socket(hostname, port);
System.out.println("Trying to send: " + com.sun.org.apache.xml.internal.security.utils.Base64.encode(infoToSend.getBytes()));
out = new DataOutputStream(socket.getOutputStream());
out.writeBytes(com.sun.org.apache.xml.internal.security.utils.Base64.encode(infoToSend.getBytes()));
out.flush();
System.out.println("Socket is flushed");
System.out.println("Waiting for Data");
InputStream is = socket.getInputStream();
System.out.println("Trying to get data");
BufferedReader input = new BufferedReader(
new InputStreamReader(is)
);
String line;
while((line = input.readLine()) != null) {
System.out.println(line);
}
socket.close();
} catch (IOException e) { e.printStackTrace(); }
}
Server:
public void run() {
System.out.println("Got Connection");
try {
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
out = new DataOutputStream(socket.getOutputStream());
String response;
System.out.println("Response:");
String decode = "";
while ((response = in.readLine()) != null) {
try {
decode = new String(Base64.decode(response));
} catch (Base64DecodingException e) {
e.printStackTrace();
}
}
System.out.println("Decoded: " + decode);
out.writeBytes("We got your message!");
out.flush();
out.close();
} catch (IOException e) { System.out.println("Fail"); e.printStackTrace(); }
Would anyone be able to guide me on how to fix this error. Sorry if it's super easy and I'm just unable to see it.
Sending
socket.shutdownOutput();
solved the issue.
I coded a server application that constantly listens to data being sent to it. I took multi-threading into consideration by the way. I have the main thread, writer thread, and reader thread. When I launch the program, everything works perfectly. After about 15 minutes of up-time though, my CPU usage just randomly skyrockets. I believe it reaches about 40% just for the server application if I remember correctly. I think I'm doing something wrong with networking since this is my first time working with sockets.
This is what I use to read data:
public void run(){
Socket s = null;
InputStream in = null;
while (Main.running){
try {
s = network.getServerSocket().accept();
in = s.getInputStream();
} catch (IOException e){
e.printStackTrace();
}
if (in != null){
DataInputStream input = new DataInputStream(in);
try {
while (input.available() != -1) {
byte type = input.readByte();
PacketIn packet = Utils.getPacket(main, type);
packet.readData(input);
if (packet instanceof PacketInLogin) {
PacketInLogin login = (PacketInLogin) packet;
login.setSocket(s);
String server = login.getServer();
Socket socket = login.getSocket();
Main.log("Login request from server: '" + server + "'. Authenticating...");
boolean auth = login.authenticate();
Main.log("Authentication test for server: '" + server + "' = " + (auth ? "PASSED" : "FAILED"));
if (auth) {
main.getServers().put(server, new DataBridgeServer(main, server, socket));
}
main.getTransmitter().sendPacket(new PacketOutAuthResult(main, auth), socket);
} else if (packet instanceof PacketInDisconnect) {
PacketInDisconnect disconnect = (PacketInDisconnect) packet;
main.getServers().remove(disconnect.getServer().getName());
Main.log("'" + disconnect.getServer().getName() + "' has disconnected from network.");
}
}
} catch (IOException e){
if (!(e instanceof EOFException)){
e.printStackTrace();
}
} finally {
if (in != null){
try {
in.close();
} catch (IOException e){
e.printStackTrace();
}
}
}
}
}
try {
if (s != null) s.close();
if (in != null) in.close();
} catch (IOException e){
e.printStackTrace();
}
}
This is what I use to write data (to the client. This code is still part of the server):
public void run(){
while (Main.running){
if (!QUEUED.isEmpty()){
PacketOut packet = (PacketOut) QUEUED.keySet().toArray()[0];
Socket server = QUEUED.get(packet);
DataOutputStream out = null;
try {
out = new DataOutputStream(server.getOutputStream());
packet.send(out);
} catch (IOException e){
e.printStackTrace();
} finally {
if (out != null){
try {
out.close();
} catch (IOException e){
e.printStackTrace();
}
}
}
QUEUED.remove(packet);
}
}
}
My program can run with inputStream.toString(); but as you know thats not a good way to convert inputStream to String. So when I try to convert properly it hangs.
My methods are:
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
if(initialized && connected){
try{
sms.findOperator();
jTextArea2.append(sms.logString);
sms.logString = "";
}
catch(Exception e){
JOptionPane.showMessageDialog(null, "Failed to find operator!", "ERROR", JOptionPane.ERROR_MESSAGE);
}
}
else JOptionPane.showMessageDialog(null, "Cannot connect to the port specified!", "ERROR", JOptionPane.ERROR_MESSAGE);
// TODO add your handling code here:
}
This is the findOperator() method:
public void findOperator(){
send("AT+COPS?\r\n");
}
Here is send() method:
public void send(String cmd) {
try {
//Thread.sleep(200);
outputStream.flush();
outputStream.write(cmd.getBytes());
inputStream = serialPort.getInputStream();
//System.out.println(" Input Stream... " + inputStream.toString());
Thread.sleep(300);
logString += inputStreamtoString(inputStream);
}
catch(Exception e){
e.printStackTrace();
}
finally{
//logString += inputStream.toString()+ '\n';
// if(infoType == "msg") return "Input Stream... " + inputStream.toString()+ '\n';
// else return inputStream.toString();
//return logString;
//logString += inputStreamtoString(inputStream);
}
}
And this is the inputStreamtoString() method:
public String inputStreamtoString(InputStream is) throws IOException{
// try {
// return new java.util.Scanner(is).useDelimiter("\\A").next();
// } catch (java.util.NoSuchElementException e) {
// return "";
// }
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
If I don't use inputStreamtoString() method and use inputStream.toString() my program runs well, but I don't get proper String. Any suggestion?
Thanks in advance...
Update: My modem uses the port COM3 with a GSM SIM card. I get a String containing huge space, like:
+COPS: <...500 spaces...> 0,0,"Banglalink"
So I hate that spaces. I need a string : +COPS: 0,0,"Banglalink"
You are trying to read exhaustively (that is until all data is read) from a stream that is connected to a serial port. This will hang if there is no data available on the port (waiting for data to come). Even if there is data, you will have an infinite loop.
UPDATE:
You could try something like this instead (adapted from code listed here):
byte[] readBuffer = new byte[200];
try {
while (is.available() > 0) {
int numBytes = is.read(readBuffer);
sb.append(new String(readBuffer, "US-ASCII"));
}
} catch (IOException e) {
// handle exception
}
UPDATE: chaged the string creation to use a specified charset (instead of the system default)