i'm having a serializabled object from class called Account. this object must be send from one device to other device using socket programing. the problem is that the Server in written in Python and the Client class written in java , some people say that it is possible to write Server class in a language different from the Client class. is there any way to do that ??
here is my code...
Client class ( Java )
public class CLIENT
{
static Socket s;
static OutputStream outputStream;
static InputStream inputStream;
static ObjectInputStream dis;
static ObjectOutputStream dos;
// Acccunt class
static class Account implements Serializable
{
String account_id = "";
int amount = 0;
}
public static void main(String[] args)
{
int Port = 50007;
try
{
Socket s = new Socket("localhost", Port);
System.out.println("Client trying to connect to port "+Port);
OutputStream outputStream = s.getOutputStream();
ObjectOutputStream dos = new ObjectOutputStream(outputStream);
InputStream inputStream = s.getInputStream();
ObjectInputStream dis = new ObjectInputStream(inputStream);
System.out.println("Ready to communicate");
while (true)
{
Account obj = new Account();
obj.account_id = "123"; obj.amount = 10000;
dos.writeObject( obj );
dos.flush();
String inn = (String) dis.readObject();
System.out.println("Server: " + inn );
}
}
catch (Exception ex) { ex.printStackTrace(); }
} // END of main
} // End of Class
Server Code ( Python )
import socket, pickle
class Account:
account_id = ""
amount = 0
HOST = 'localhost'
PORT = 50007
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(5)
conn, addr = s.accept()
print ('Connected by', addr)
data = conn.recv(4096)
data_variable = pickle.loads(data)
print( data_variable.account_id )
conn.send('Thank you for connecting'.encode())
conn.close()
Related
I have created a watchOS app that fetches data from the accelerometer and gyroscope and sends it to a socket server. The server just prints the data on the console. The socket server is made in python. My app works fine for a few minutes but then stops working.
I tested by creating an iPhone app and it's working fine. The problem is with the apple watch app.
Can someone help me with this? I don't understand what's going on.
server.py
import socket
localIP = ""
localPort = 20001
bufferSize = 10240
msgFromServer = "Hello UDP Client"
bytesToSend = str.encode(msgFromServer)
# Create a datagram socket
UDPServerSocket = socket.socket(family=socket.AF_INET, type=socket.SOCK_DGRAM)
# Bind to address and ip
UDPServerSocket.bind((localIP, localPort))
print("UDP server up and listening")
# Listen for incoming datagrams
while(True):
bytesAddressPair = UDPServerSocket.recvfrom(bufferSize)
message = bytesAddressPair[0]
address = bytesAddressPair[1]
clientMsg = "Message from Client:{}".format(message)
clientIP = "Client IP Address:{}".format(address)
print(clientMsg)
print(clientIP)
# Sending a reply to client
UDPServerSocket.sendto(bytesToSend, address)
InterfaceController.swift
#IBOutlet weak var stopButton: WKInterfaceButton!
#IBOutlet weak var startButton: WKInterfaceButton!
var session = WKExtendedRuntimeSession()
private var host: NWEndpoint.Host = "172.16.105.162"
private var port: NWEndpoint.Port = 20001
private var updateTimeInterval: Double = 1/60
override func awake(withContext context: Any?) {
// Configure interface objects here.
// startButton.setHidden(false)
startButton.setEnabled(true) // // stopButton.setHidden(true)
stopButton.setEnabled(false)
setUPSession()
}
override func willActivate() {
// This method is called when watch view controller is about to be visible to user
print("ACTIVATE")
}
override func didDeactivate() {
// This method is called when watch view controller is no longer visible
print("DEACTIVATE")
}
#IBAction func actionStop() { // startButton.setHidden(false)
startButton.setEnabled(true) // // stopButton.setHidden(true)
stopButton.setEnabled(false)
self.stopSession()
// MotionDatafetcher.shared.startSession() //stopWorkoutSEssion() //stopFetch()
}
#IBAction func actionStart() { // startButton.setHidden(true)
startButton.setEnabled(false) // // stopButton.setHidden(false)
stopButton.setEnabled(true)
self.startSession()
// MotionDatafetcher.shared.startFetch()
//MotionDatafetcher.shared.stopSession() //startWorkoutSession() //startDeviceMotionFetch()
}
}
extension InterfaceController : WKExtendedRuntimeSessionDelegate{
func setUPSession() {
// Create the session object.
session = WKExtendedRuntimeSession()
// Assign the delegate.
session.delegate = self
MySocketManager.shared.setUpConn()
}
func startSession() {
session.start()
MySocketManager.shared.connectToUDP(host, port)
MotionDatafetcher.shared.startDeviceMotionFetch(updateTimeInterval)
}
func stopSession() {
session.invalidate()
MotionDatafetcher.shared.stopFetch()
MySocketManager.shared.cancelConnToUDP()
}
func extendedRuntimeSession(_ extendedRuntimeSession: WKExtendedRuntimeSession, didInvalidateWith reason: WKExtendedRuntimeSessionInvalidationReason, error: Error?) {
}
func extendedRuntimeSessionDidStart(_ extendedRuntimeSession: WKExtendedRuntimeSession) {
}
func extendedRuntimeSessionWillExpire(_ extendedRuntimeSession: WKExtendedRuntimeSession) {
self.stopSession()
}
}
I am currently trying to send ble data from the app to my PC using sockets. As of now, I am able to send data to the server, but the server only receives one data and then stops receiving. I am suspecting that there is something wrong with my client side code. Any help would be appreciated
My SocketClass code:
inner class SocketClass{
fun doInBackground(message: String): String {
try {
socket = Socket(SERVER_IP, SERVERPORT)
val outputStream = OutputStreamWriter(socket?.getOutputStream())
val printwriter = BufferedWriter(outputStream)
printwriter.write(message)
printwriter.flush()
printwriter.close()
socket?.close()
} catch (e: Exception) {
e.printStackTrace()
}catch (e: UnknownHostException){
}
return ""
}
}
and in the blereadcharacteristic I call the class in a thread like this:
private fun readDeviceCharacteristic(characteristic: BluetoothGattCharacteristic) {
var hashval:MutableMap<String, String> = mutableMapOf()
var mainThreadList :MutableList<String> = mutableListOf()
var currentTime: String = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS").withZone(
ZoneId.of("Asia/Seoul")).format(Instant.now()) // Get current Timestamp
if(idlist.size != 0) {
readval = characteristic.getStringValue(0)
valdata = readval.subSequence(3, readval.length).toString()
idNo = readval.subSequence(0, 2).toString()
parseList.add(readval)
mainThreadList = parseList.toMutableList().distinctBy{it.subSequence(0, 2)} as MutableList<String>
if(mainThreadList.size == maxConnLimit) {
bleDataList = mainThreadList
bleDataList.forEach{
hashval[it.subSequence(0, 2).toString()] = it.subSequence(3, it.length).toString()
}
loghash = hashval.toSortedMap()
txtRead = bleDataList.toString()
parseList.clear()
if(isChecked) {
savehash["Time"]?.add("$sec.$millis")
bleDataList.forEach {
savehash[it.subSequence(0, 2).toString()]?.add(
it.subSequence(
3,
it.length
).toString()
)
}
}else{
time = 0
sec = 0
millis = ""
}
if(isInsert){
Thread{
SocketClass().doInBackground("$loghash\r\n\r\n")
}.start()
}
}
}
isTxtRead = true
bleDataList.clear()
}
My server socket python code:
import socket
import sys
host = '19.201.12.12'
port = 30001
address = (host, port)
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.bind(address)
server_socket.listen(5)
print("Listening for client . . .")
conn, address = server_socket.accept()
print("Connected to client at ", address)
while True:
output = conn.recv(2048);
if output.strip() == "disconnect":
conn.close()
sys.exit("Received disconnect message. Shutting down.")
elif output:
print("Message received from client:")
print(output)
I am able to get the first data sent, but do not receive anything after. Any help would be greatly appreciated thankyou!
Your server code only accepts one client connection. So, here's the timelime.
Python waits at accept.
Kotlin connects
Python moves into while True loop.
Kotlin writes, then closes the socket.
At that point, nothing further will be received by the Python code, but because you never call accept again, you can't accept another connection.
You need to have the accept in a loop. You handle that connection until it closes, then you loop to another accept.
You might consider using the socketserver module, which automates some of this.
I have an android app that sends an image from gallery to a Python server via sockets using DataOutputStream to write to the socket in the client app. The image is loaded from external storage directory and buffered before being sent. The image is received by the server and written to disk memory. When I try to open the image it gives me: "Fatal Error reading the image file. Not a PNG". However the image occupies an actual image size of 430 KiB. When I print the data being received it gives me something that looks like a raw image:
b'\x97\xa7p\xc0\x04\xfbv\xf6\\\xed\x8a\xe9^\xbf\xa4p9\xae\x8eu:N\xb5\x8e\xcc\x06\xa6\xf1\tyL\xf3.^W\xb5RR\xd3)\x7fS\xf3\x8f\x1b\xc6\xf8\xa7\x9b\xf5\xb8\xc3f\xa9\xdf\xa1\xbd\xaa\xbeS\xbc\x84zt\xedT\xbfn|I\xfb\x0e\xfb\xae6\x18sS\x9b\x9e\xd8\xff\xc4>\xaf\xeb\xba\xbe>{\xe2\x87~\xe8\x87~\xe8\x87~\xe8\x87~\xe8\x87~\xe8\x87~\xe8\x87~\xe8\x87~\xe8\x87~\xe8\x87~\xe8\x87\xfe\xbf\xa4\xff\x07\xe5\x9f\xdc\xd5\xe2d\xc5\xcb\x00\x00\x00\x00IEND\xaeB`\x82'
b''
The text is longer but I cut it down..
The client code that loads the image from directory and writes to socket:
class send extends AsyncTask<Void, Void, Void> {
Socket s; //Socket Variable
#Override
protected Void doInBackground(Void... params) {
try {
s = new Socket("192.168.0.14", 9999);
String image = getLatestFilefromDir("/storage/emulated/0/DCIM");
File file = new File(image);
try (InputStream is = new BufferedInputStream(new FileInputStream(file));
DataOutputStream dos = new DataOutputStream(s.getOutputStream())) {
dos.writeLong(file.length());
int val;
while ((val = is.read()) != -1) {
dos.write(val);
}
dos.flush();
} catch (IOException e) {
e.printStackTrace();
}
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
private String getLatestFilefromDir(String dirPath){
File dir = new File(dirPath);
File[] files = dir.listFiles();
if (files == null || files.length == 0) {
return null;
}
File lastModifiedFile = files[0];
for (int i = 1; i < files.length; i++) {
if (lastModifiedFile.lastModified() < files[i].lastModified()) {
lastModifiedFile = files[i];
}
}
return lastModifiedFile.toString();
}
Python server:
#Imports modules
import socket
import datetime
date_string = datetime.datetime.now().strftime("%Y-%m-%d-%H:%M")
listensocket = socket.socket()
listenPort = 9999
numberOfConnections=1
thisIp = socket.gethostname()
listensocket.bind(('', listenPort))
listensocket.listen(numberOfConnections)
print("Started Listening")
(clientsocket, address) = listensocket.accept()
print("Connected")
fname = "/home/pi/Desktop/Images/"+date_string+".PNG"
f = open(fname, 'wb')
datain = 1
while datain:
datain = clientsocket.recv(100000000)
print(datain)
bytearray(f.write(datain))
f.close()
listensocket.close()
This answer may not be robust but does demonstrate a mechanism for efficiently transferring files from a Java application to a Python server. Certain paths are hard-coded for demonstration purposes. Also note that this may not be appropriate if the file being transferred is very large due to the fact that the entire file contents will be held in memory on the server side before writing to the target file. Obviously that can be accounted for with more elaborate code.
Here's the Java client:
package com.aprk;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.Socket;
import java.util.logging.Level;
import java.util.logging.Logger;
public class GetImage {
public static void main(String[] args) {
try {
Socket s = new Socket("localhost", 7070);
File image = new File("/Volumes/G-DRIVE Thunderbolt 3/Pictures/rgb_colour_wheel.png");
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(image));
BufferedOutputStream bos = new BufferedOutputStream(s.getOutputStream());
bos.write(nio(image.length()));
byte[] buff = new byte[4096];
int n;
while ((n = bis.read(buff, 0, buff.length)) > 0) {
bos.write(buff, 0, n);
}
bos.flush();
} catch (IOException ex) {
Logger.getLogger(GetImage.class.getName()).log(Level.SEVERE, null, ex);
}
}
private static byte[] nio(long n) {
byte[] v = new byte[8];
int shift = 56;
for (int i = 0; i < 8; i++) {
v[i] = (byte)(n>>shift);
shift -= 8;
}
return v;
}
}
Here's the Python server:
import socket
from struct import unpack
HOST = '0.0.0.0'
PORT = 7070
def main():
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind((HOST, PORT))
s.listen()
conn, _ = s.accept()
with conn:
p = conn.recv(8, socket.MSG_WAITALL)
n = unpack('!Q', p)[0]
with open('/tmp/image.png', 'wb') as image:
while n > 0:
data = conn.recv(n)
image.write(data)
n -= len(data)
if __name__ == '__main__':
main()
I need to stream video from a Raspberry Pi's camera (Python server), to a C# script client (Unity, in fact).
I have successfully done this, using a Python to Python workflow, but I can't manage to make It work on C# client side.
This is my python server, where I'm sending the Stream over sockets:
Server.py:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(('0.0.0.0', 24000))
s.listen(1)
connection = s.accept()[0].makefile('wb')
print ('Client connected')
while True:
stream = io.BytesIO()
for foo in camera.capture_continuous(stream, 'jpeg'):
connection.write(struct.pack('<L', stream.tell()))
connection.flush()
stream.seek(0)
connection.write(stream.read())
stream.seek(0)
stream.truncate()
And this is my Python client side, which is actually working:
Client.py:
def threadLoop(self):
self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.socket.connect((self.ip, self.port))
connection = self.socket.makefile('rb')
print('Recibiendo fotos')
while not self.haltSignal():
image_len, image_width, image_height = struct.unpack('<LLL', connection.read(struct.calcsize('<LLL')))
print ("L: " + str(image_len) + " W: " + str(image_width) + " H: " + str(image_height))
if not image_len:
break
image_stream = io.BytesIO()
image_stream.write(connection.read(image_len))
image_stream.seek(0)
self.callback(image_stream.getvalue(), image_width, image_height)
self.socket.close()
self.socket = None
self.thread = None
So, the question is... having this Server.py, how can I make a C# client that receives the stream and show the pictures?
I've tried to capture the received data in C#, over the socket, store It in a Byte array and convert It to a readable image, which sometimes, when It's a (very)small sized picture, works fine. I guess there must be a better way to achieve this.
Thanks!
Edit: This is what I've been trying in C#. Thanks again!
public int Connect()
{
if (_clientSocket.Connected == false)
{
_clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
mutexToSend = new Mutex();
mutexReceived = new Mutex();
ThreadStart ts = new ThreadStart(SendReceiveData);
threadSend = new Thread(ts);
threadSend.Start();
return 1;
}
else
return 0; //There is a socket already connected.
}
//----------------------------------------------------------
private void SendReceiveData()
{
try
{
_clientSocket.SendTimeout = 1000;
_clientSocket.ReceiveTimeout = 1000;
System.Net.IPAddress ipaddress = this.serverIP;
_clientSocket.Connect(new IPEndPoint(ipaddress, this.serverPort));
}
catch (SocketException ex)
{
//turn ex.Message;
}
_clientSocket.BeginReceive(_recieveBuffer, 0, _recieveBuffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallback), null);
}
//----------------------------------------------------------
private void ReceiveCallback(IAsyncResult AR)
{
//Check how much bytes are recieved and call EndRecieve to finalize handshake
int recieved = _clientSocket.EndReceive(AR);
if (recieved <= 0)
{
GestorCamaraSala.imgReceived = _recieveBuffer; //I copy the received data to the image texture
return;
}
//Start receiving again
_clientSocket.BeginReceive(_recieveBuffer, 0, _recieveBuffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallback), null);
}// end ReceivedCallback
First of all I want to mention that I've gone through a lot of socket threading tutorials before attempting to integrate it into my own GUI, but I still consider myself fairly new to the subject.
I have a server written in python that opens a socket and starts a thread over localhost, and listens over the port for a client:
def StartThread():
tcpsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
tcpsock.bind((TCP_IP, TCP_PORT))
threads = []
tcpsock.listen(5)
print "Waiting for incoming connections from client..."
(conn, (ip,port)) = tcpsock.accept()
print 'Got connection from ', (ip,port)
newthread = ClientThread(ip,port,conn, 1)
newthread.start()
return newthread
Here is the ClientThread class:
class ClientThread(Thread):
def __init__(self,ip,port,sock, status):
Thread.__init__(self)
self.ip = ip
self.port = port
self.sock = sock
self.status = 1
print " New thread started for "+ip+":"+str(port)
After I run the server code, I click a button on my C++ GUI which runs the client code StartConnection() based off the Microsoft Winsock client template.
void CPSR_CRSDlg::OnBnClickedInit2()
{
if(!checkTimerStarted())
// Set mmtimer to aquire the data
{
m_ntimerID = timeSetEvent( TIMERINTRRVAL,
1,
timerHandler,
0,
TIME_PERIODIC);
SetTimer(1,TIMERINTRRVAL_2,NULL);
m_bTimer_started = true;
}
StartConnection();
}
The connection does start successfully and the python code prints the address of the connection and the thread, but then my GUI freezes, so that I can't click any of the other buttons to actually send data over the connection.
Why does my application freeze? Am I not instantiating the thread correctly?
The StartConnection() code is off the msdn website but here is my slightly modified version if needed:
void StartConnection(){
//printf("Connection Starting... \n");
WSADATA wsaData;
ConnectSocket = INVALID_SOCKET;
struct addrinfo *result = NULL,
*ptr = NULL,
hints;
int argc = 2;
// Validate the parameters
if (argc != 2) {
printf("usage: %s server-name\n", "client");
return;
}
// Initialize Winsock
iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
if (iResult != 0) {
printf("WSAStartup failed with error: %d\n", iResult);
return;
}
ZeroMemory( &hints, sizeof(hints) );
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
// Resolve the server address and port
//iResult = getaddrinfo(argv[1], DEFAULT_PORT, &hints, &result);
iResult = getaddrinfo("localhost", DEFAULT_PORT, &hints, &result);
if ( iResult != 0 ) {
printf("getaddrinfo failed with error: %d\n", iResult);
WSACleanup();
return;
}
// Attempt to connect to an address until one succeeds
for(ptr=result; ptr != NULL ;ptr=ptr->ai_next) {
// Create a SOCKET for connecting to server
ConnectSocket = socket(ptr->ai_family, ptr->ai_socktype,
ptr->ai_protocol);
if (ConnectSocket == INVALID_SOCKET) {
printf("socket failed with error: %ld\n", WSAGetLastError());
WSACleanup();
return;
}
// Connect to server.
iResult = connect( ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen);
if (iResult == SOCKET_ERROR) {
closesocket(ConnectSocket);
ConnectSocket = INVALID_SOCKET;
continue;
}
break;
}
freeaddrinfo(result);
if (ConnectSocket == INVALID_SOCKET) {
printf("Unable to connect to server!\n");
WSACleanup();
return;
}
return;
}
void StopConnection(){
closesocket(ConnectSocket);
WSACleanup();
return;
}
void SendJointValues(double *joints){
iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0);
j = parseJSON(joints[0],joints[1],joints[2],joints[3], \
joints[4],joints[5]);
int x = send(ConnectSocket, j, strlen(j), 0);
//iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0);
}
Edit:
The GUI does respond again after I send data via the server, and the client then successfully sends back one iteration of data. But after this exchange the GUI freezes again until more data is sent.
Here is the send+receive portion of the server:
def receiveData(self):
while (self.status == 1):
joints = [0,0,0,0,0,0]
self.sock.sendall('send')
print "Data Sent!"
data = self.sock.recv(4096)
print "Data received: ", data
self.checkStatus(data)
print "Status is: ", self.status
if (self.status == 1):
data_loaded = json.loads(data)
joints = self.createJointArr(data_loaded['Joints'])
time.sleep(0.5)
print joints
return joints
And the SendJointValues() in the client is called in this Timer function:
void CPSR_CRSDlg::OnTimer(UINT_PTR nIDEvent)
{
CString str;
long Position;
double engPosition;
double dblPosition;
double dblSpeed;
bool ret;
// Arch
USB4_01.Controller_3.getEncoderPosition(Position);
countTodegree(Position,engPosition,ARCH);
str.Format(_T("%10.2f"),engPosition);
m_staPosArch.SetWindowText(str);
// Wrist Pitch
USB4_01.Controller_2.getEncoderPosition(Position);
countTodegree(Position,engPosition,TILT);
str.Format(_T("%10.2f"),engPosition);
m_staPosPitch.SetWindowText(str);
// Linear
USB4_02.Controller_1.getEncoderPosition(Position);
countTodegree(Position,engPosition,LINEAR);
str.Format(_T("%10.2f"),engPosition);
m_staPosLinear.SetWindowText(str);
// Turret
USB4_02.Controller_2.getEncoderPosition(Position);
countTodegree(Position,engPosition,TURRET);
str.Format(_T("%10.2f"),engPosition);
m_staPosTurret.SetWindowText(str);
// Roll
USB4_02.Controller_4.getEncoderPosition(Position);
countTodegree(Position,engPosition,ROLL);
str.Format(_T("%10.2f"),engPosition);
m_staPosRoll.SetWindowText(str);
// Drill/Tool
USB4_02.Controller_3.getEncoderPosition(Position);
countTodegree(-Position,engPosition,DRILL);
str.Format(_T("%10.2f"),engPosition);
m_staPosDrill.SetWindowText(str);
// For Penetrate joint
if(JntPenetration.isInitialized())
{
// Get Position feedback
ret = JntPenetration.getPosition(dblPosition);
if(ret) // get position feedback successfully
{
Position = (long) dblPosition;
countTodegree(Position,engPosition,PENETRATE);
str.Format(_T("%10.2f"),engPosition);
m_staPosPenetrate.SetWindowText(str);
m_dCurentPentrationPosition = engPosition;
}
// Get Speed feedback;
if(m_bDrilling_started)
{
// Penetration position close enough AND At least on cycle reached
if( (abs(engPosition - m_dDrilling_target_position) < 0.1) &&(m_Direction_Changed == true))
m_bPenetrationStopped = true;
else
m_bPenetrationStopped = false;
//JntPenetration.getSpeed(dblSpeed);
//if(dblSpeed < .05 )
// m_bPenetrationStopped = true;
//else
// m_bPenetrationStopped = false;
}
}
SendJointValues(JointArray);
// For drilling motion control
if(m_bDrilling_started)
drilingProcedure();
CDialog::OnTimer(nIDEvent);
}