I'm trying to create a proxy in Android and I have to use sockets . I've read many tutorials and came up with following code. Unfortunately browser doesn't seem to get any data and after some time it displays standard web page saying that web page is not available. What might be the cause? Thanks for your help.
ServerSocket serverSocket = null;
try {
serverSocket = new ServerSocket(9902, 0, InetAddress.getByName("localhost"));
} catch (Exception e) {
e.printStackTrace();
}
if (serverSocket != null) {
while (!Thread.currentThread().isInterrupted()) {
try {
Socket socket = serverSocket.accept();
new Thread(new RunnableToReadSocketData(socket)).start();
} catch (Exception e) {
e.printStackTrace();
}
}
}
private class RunnableToReadSocketData implements Runnable {
private final Socket clientSocket;
public RunnableToReadSocketData(Socket socket) {
this.clientSocket = socket;
}
#Override
public void run() {
Socket serverSocket = null;
try {
InputStream streamFromClient = clientSocket.getInputStream();
PrintWriter streamToClient = new PrintWriter(clientSocket.getOutputStream());
StringWriter writer = new StringWriter();
IOUtils.copy(streamFromClient, writer);
String requestString = writer.toString();
int firstSpace = requestString.indexOf(" ");
int secondSpace = requestString.indexOf(" ", ++firstSpace);
String url = requestString.substring(firstSpace, secondSpace);
Uri uri = Uri.parse(url);
String urlWithoutProtocol = uri.getHost();
System.out.println("==============Reading Socket==============\n" + clientSocket.toString() + "\n" + requestString);
serverSocket = new Socket(urlWithoutProtocol, 80);
PrintWriter streamToServer = new PrintWriter(serverSocket.getOutputStream(), true);
streamToServer.write(requestString);
streamToServer.flush();
InputStream streamFromServer = serverSocket.getInputStream();
StringWriter writerResponse = new StringWriter();
IOUtils.copy(streamFromServer, writerResponse);
String responseString = writerResponse.toString();
System.out.println("==============RECEIVED==============\n" + serverSocket.toString() + "\n" + responseString);
streamToClient.write(responseString);
streamToClient.flush();
streamToClient.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (serverSocket != null) {
serverSocket.close();
}
if (clientSocket != null) {
clientSocket.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
You're doing this wrong. After you process the CONNECT command you need to start two threads to copy bytes over the connection, one in each direction. Don't attempt to read the entire request before you send anything; ditto the response. Just copy bytes as you receive them.
When you read EOS on one socket, shutdown the other socket for output and exit that thread. If you've already shutdown the socket you read the EOS from, close both and exit the thread. You need this in case either end does a shutdown, to propagate it properly.
I agree with previous.
The general principle is:
Client connects
Start reading thread
Receive request
Parse destination
Open socket to destination
Forward request
For every Read on the destination socket, do a write on the client socket
For every Read on client socket, do a write on destination socket
If either socket closes (errors), close the other
So, two InputStream's, two OutputStreams, and just ferry data across them.
Related
I wrote a class in which I can send and receive data via socket. In this class, first of all, I connect to socket with a specific port and IP then, I initialize outputstrem and inputstram.
I can easily send and receive data, but I can only receive data when there is a request from my side. Sometimes I have to receive new information without sending data.
How can I receive data (listen to socket) without sending data?
public class INetConnection{
private DataOutputStream outputStream;
private DataInputStream inputStream;
private Callback mCallback;
private Socket socket;
private byte[] rec_buffer;
public Socket getSocket() {
return socket;
}
public void setSocket(Socket socket) {
this.socket = socket;
}
public void connectToNetwork() {
if (socketConnect()) {
try {
outputStream = new DataOutputStream(getSocket()
.getOutputStream());
inputStream = new DataInputStream(getSocket().getInputStream());
Log.i("Log", "Streams Created!");
receiveData();
} catch (IOException e) {
e.printStackTrace();
}
}
}
private boolean socketConnect() {
try {
socket = new Socket(SERVER_IP, SERVER_PORT);
Log.i("Socket", "Connection stablished");
return true;
} catch (UnknownHostException e) {
Log.d("Exception mode", "UnknownHostException");
e.printStackTrace();
} catch (IOException e) {
Log.d("Exception mode", "IOException");
e.printStackTrace();
}
return false;
}
public void sendData(final byte[] data) {
outputStream.write(data, 0, data.length);
}
private void receiveData(){
// Again, probably better to store these objects references in the support class
if(getSocket() != null && getSocket().isConnected()){
try {
Log.i("Log", "Ready to receive!");
byte[] buffer = new byte[265536];
int size = 0;
while ((size = inputStream.read(buffer)) != -1){
Log.i("Log", "Data's been read fully from server");
rec_buffer = new byte[size];
rec_buffer = Arrays.copyOfRange(buffer, 0 , size);
for (int i = 0; i< size; i++)
Log.i("Log", "Data i: " + rec_buffer[i]);
}
} catch (IOException e) {
Log.e("Log", "Error occured during receiving data");
e.printStackTrace();
}
}
}
}
Is the server you are connecting to via the socket your own server with your own implementation or somebody else's server?
Usually the server would behave in a way that it will send data only upon request (at least REST APIs are behaving that way). However, if that is your own server, you can set it up in a way that once socket is connected, it will start sending data to the client. In that way, the InputStream on your client should be able to receive the data without sending anything.
If the server is not yours to modify and is expecting the client to send a request first, then I guess there's nothing much you can do other than to send data from your client first.
I attempting to build a remote controller for my laptop using my phone.
I written a server application that running on my laptop, the remote app used as a client to the server application.
I want to implement a mouse pad, the problem is when I am moving my finger over the "touch pad" too fast, I am receiving read time out on server side after few iterations.
Server code
final ExecutorService clientProcessingPool = Executors.newFixedThreadPool(20);
Runnable serverTask = new Runnable()
{
#Override
public void run()
{
ServerSocket serverSocket = null;
try
{
serverSocket = new ServerSocket(DEFAULT_PORT);
serverSocket.setReuseAddress(true);
_working = true;
while (_working)
{
Socket clientSocket = serverSocket.accept();
clientSocket.setSoTimeout(10000);
clientProcessingPool.submit(new ClientTask(clientSocket));
}
}
catch (IOException e)
{
System.err.println("Unable to process client request");
e.printStackTrace();
}
finally
{
try
{
if (serverSocket != null)
{
serverSocket.close();
}
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
};
Thread serverThread = new Thread(serverTask);
serverThread.start();
private class ClientTask implements Runnable
{
private final Socket clientSocket;
private ClientTask(Socket clientSocket)
{
this.clientSocket = clientSocket;
}
#Override
public void run()
{
System.out.println("Got a client !");
try
{
System.out.println("Connected!");
DataOutputStream dOut = new DataOutputStream(clientSocket.getOutputStream());
DataInputStream dIn = new DataInputStream(clientSocket.getInputStream());
String request = dIn.readUTF();
parseRequest(request);
System.out.println("request=" + request);
dOut.writeUTF("Got the command");
dOut.flush(); // Send off the data
dIn.close();
dOut.close();
clientSocket.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
I thought maybe I will send the requests only if the distance from the starting position to end position is bigger than STEPS(a constant) and only then send the request. But I think the mouse won`t move fluidly.
Thanks.
RXAndroid and RXJava are perfect for asynchronously handling these request and will allow you to add a debounce to the frequent requests. Check out Reactive.io
I'd like write an app to transfer data between 2 android devices on the same wifi network, like as there is a share folder.
How can i do this?
Thanks
EDIT (My solution):
My Server wait for request
private boolean startServer() {
try {
server = new ServerSocket(port);
} catch (IOException ex) {
ex.printStackTrace();
return false;
}
return true;
}
public void runServer() {
while (this.go) {
try {
Log.d("BurgerClub", "Server in attesa di richieste");
Socket s1 = server.accept();
OutputStream s1out = s1.getOutputStream();
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(
s1out));
BufferedReader br = new BufferedReader(new FileReader(this.path));
String counter = br.readLine();
counter = counter != null ? counter : "000";
br.close();
bw.write(counter);
bw.close();
s1.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
My Client (Runnable object)
public void run() {
try {
this.openConnection();
// Se il socket รจ connesso
if( !this.s1.isClosed() ) {
InputStream is = this.s1.getInputStream();
BufferedReader dis = new BufferedReader(new InputStreamReader(is));
line = dis.readLine();
if( !this.previousCounter.equals(line.trim()) ) {
((BurgerClub_MonitorActivity) counterContext).runOnUiThread(new Runnable() {
#Override
public void run() {
TextView edit = (TextView)(((BurgerClub_MonitorActivity) counterContext).findViewById(R.id.textActionCounter));
edit.setText(line);
}
});
this.previousCounter = line.trim();
}
dis.close();
}
} catch (ConnectException connExc) {
connExc.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
} catch (Throwable ex) {
ex.printStackTrace();
}
One device needs to serve as a server and the other one will be the client.
The basic flow needs to be something of this sort:
Server device opens a socket and listens on it.
Server device broadcasts the local IP and port it's listening on.
Client device receives broadcast and initiates a connection.
Perform data transfer.
Read about NFC (Near field communication)
http://developer.android.com/guide/topics/connectivity/nfc/index.html
Hey community I have the following ServerSocket which should listen to port 53000 and log any received data. However, I cannot seem to get past the server.accept() blocking call.
public void run() {
SocketServer server = new ServerSocket(53000);
//---buffer store for the stream---
byte[] buffer = new byte[1024];
//---bytes returned from read()---
int bytes;
//---keep listening to the InputStream until an
// exception occurs---
while (true) {
try {
socket = server.accept();
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String str = in.readLine();
Log.i("received response from server", str);
in.close();
socket.close();
} catch (IOException e) {
Log.e(TAG, e.getMessage());
} catch (Exception e){
server.close();
Log.e(TAG, e.getMessage());
}
}
}
I have also given the application the INTERNET permission in the Manifest file.
()
To add to the mystery, I have also verified client responses get sent to that port.
Is there something in particular I need to do to make this work?
Thanks.
Your code is very messy and won't even compile. I made some adjustments so that i could test your code, and it's working fine. Here is the test application I used:
package com.test.stackoverflow
import java.io.BufferedReader;
public class ServerSocketTestActivity extends Activity {
/** Called when the activity is first created. */
private static String TAG = "ServerSocketTest";
private ServerSocket server;
Runnable conn = new Runnable() {
public void run() {
try {
server = new ServerSocket(53000);
while (true) {
Socket socket = server.accept();
BufferedReader in = new BufferedReader(
new InputStreamReader(socket.getInputStream()));
String str = in.readLine();
Log.i("received response from server", str);
in.close();
socket.close();
}
} catch (IOException e) {
Log.e(TAG, e.getMessage());
} catch (Exception e) {
Log.e(TAG, e.getMessage());
}
}
};
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new Thread(conn).start();
}
#Override
protected void onPause() {
super.onPause();
if (server != null) {
try {
server.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Using this code and netcat running via adb shell I was able to connect and communicate with the application.
When working with The Client Declare these methods
To access Streams
// gets the input stream // ObjectInputStream input;
// gets the output stream // ObjectOutputStream output;
// ServerSocket server;
// Socket connection;
maybe you have a another class to access the socket;
server = new ServerSocket(5001, 100);
// step 1 create socket connection
server = new ServerSocket(5001, 100);
while(the condition is true)
// step 2 wait for connection
// step 3 get streams
// step 4 : process the connection
// step 5 : close connection
I am a beginner in developing the java applications. I'm making a chat application on android. I use a thread to serve the client who comes in, but when the client has connected to the server I can not retrieve the data contained in the socket, but when a client connection is lost, data can be displayed. I use the ReadLine method to read data from the socket.
This is the program code on the server side:
package server;
import java.net.*;
import java.io.*;
import java.util.Vector;
import com.sun.org.apache.bcel.internal.generic.NEW;
public class Server {
public static void main(String[] args)throws IOException, InstantiationException,
IllegalAccessException {
ServerSocket servsocket = null;
Socket sock = null;
byte[] bytebuffer = new byte[512];
try {
System.out.println("SERVER IS RUNNING...");
servsocket = new ServerSocket(28000);
while(true){
sock = servsocket.accept();
System.out.println(servsocket.isBound());
System.out.println("Port "+servsocket+" Ready!!!");
System.out.println("Accept connection requests from " + sock);
System.out.println("From CLIENT "+sock.getInetAddress()+ " and PORT " +
sock.getPort());
ChatThread thread = new ChatThread(sock);
System.out.println("Thread is running");
thread.run();
}
} catch (IOException ioe) {
System.out.println(ioe);
}
finally{
try {
servsocket.close();
} catch (IOException ioe) {
System.out.println(ioe);
}
}
}
}
class ChatThread extends Thread{
static Vector<ChatThread> chatthread = new Vector<ChatThread>(10);
private Socket sock;
private BufferedReader in ;
private PrintWriter out;
public ChatThread (Socket socket) throws IOException {
this.sock = socket;
in = new BufferedReader(
new InputStreamReader(socket.getInputStream()));
out = new PrintWriter(
new OutputStreamWriter(socket.getOutputStream()));
byte[] bytebuffer = new byte[512];
int receivemssg;
}
public void run(){
int recvMsgSize;
byte[] bytebuffer = new byte[512];
String readsocket;
try {
readsocket = in.readLine();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Below the display on the server side when the program starts. I tried to send the word "Hello ...." from the client side. Can be seen that the thread is not running.
Server is running...
true
Port ServerSocket[addr=0.0.0.0/0.0.0.0,port=0,localport=28000] Ready!!!
Accept connection requests fromSocket[addr=/172.17.231.254,port=3567,localport=28000]
From CLIENT /172.17.231.254 and PORT 3567
Thread is Running...
When I replace the readline method on a thread with getInputStream the thread can be run from the client and the message can be displayed. This is the code that I enter the thread to replace the readline method that I used before.
public ChatThread (Socket socket) throws IOException {
this.sock = socket;
in = sock.getInputStream();
out = sock.getOutputStream();
byte[] bytebuffer = new byte[512];
int receivemssg;
}
public void run(){
int recvMsgSize;
byte[] bytebuffer = new byte[512];
System.out.println("Thread is Running...");
String masuk = new String(bytebuffer);
System.out.println(bytebuffer);
System.out.println(in.toString());
System.out.println("thread successfully executed !!!");
synchronized (chatthread) {
chatthread.addElement(this);
}
try {
while ((recvMsgSize = in.read(bytebuffer)) != -1) {
out.write(bytebuffer, 0, recvMsgSize);
System.out.println("The length of a character is received and returned "+bytebuffer.length);
}
} catch (IOException e) {
System.out.println(e);
}
}
}
but the next problem is I can not bring up the contents of a socket in a string / text that appears is as follows:
Port ServerSocket[addr=0.0.0.0/0.0.0.0,port=0,localport=28000] Siap!!!
Accept connection requests fromSocket[addr=/172.17.231.254,port=3577,localport=28000]
From CLIENT /172.17.231.254 and PORT 3577
Thread is Running...
[B#7c6768
java.net.SocketInputStream#1690726
thread successfully executed !!!
The length of a character is received and returned 512
Please Help me, thanks :) GBU guys...
See the developer docmentation
public final String readLine ()
Since: API Level 1
Returns a string containing the next line of text available from this stream.
A line is made of zero or more characters followed by '\n', '\r', "\r\n"
or the end of the stream. The string does not include the newline sequence.
readLine() will block and not return until it either sees an end-of-line condition such as a newline character, or the end of the stream is reached, which is probably what happens when the connection is lost.
If you want to use readLine() you need to send "Hello....\n" or otherwise append a terminating character for readLine() to see.