Develop Reference

Sending bluetooth data between Android and Hololens

I have created an application to Android and Microsoft Hololens, where it is possible to send some GPS-data with bluetooth from an Android-phone to a Hololens (with Bluetooth LE Advertiser) and that works allright. But when I am trying to send other data from Hololens to Android, I have a problem that Android-phone can't discover Hololens, although these devices are paired. Is it even possible to send data from Hololens with bluetooth, or is there only something wrong in my code? Does Bluetooth LE Advertising support two-way data transfering?

I am guessing you have a BluetoothConnected thread in your android app with an InputStream (mine is mmInStream). Try using this as your 'run' function in the thread:
public void run() {
System.out.println("BT THREAD RUNNING");
mmBuffer = new byte[1024];
int numBytes; // bytes returned from read()
InputStreamReader mmInStreamReader = new InputStreamReader(mmInStream);
BufferedReader mmReader = new BufferedReader(mmInStreamReader);
// Keep listening to the InputStream until an exception occurs.
while (true) {
try {
// Read from the InputStream.
Thread.sleep(100);
String s = mmReader.readLine();
Thread.sleep(100);
//Static class that handles the response
BluetoothCommunications.responseHandler(s);
} catch (IOException e) {
System.out.println("Input stream was disconnected" + e);
main.disconnected();
break;
} catch (Exception e) {
System.out.println(e.getMessage());
}
}
}

Android Bluetooth SPP - How to stop transmitting the internal send buffer ?

I am trying to control/operate a motor from an android phone in "as close as possible" realtime using the Android SPP Bluetooth socket interface. The motor ought to run in a so called 'dead man' operation mode. So the motor will only turn if a button on the android APP is touched and ought to stop immediately if the touch is released.
I implemented this by continuously sending 'keep turning' telegrams of 20 Bytes about every 20ms to keep the motor turning and to have the motor stop immediately as soon as no more telegrams are received or if a STOP telegram is received.
This seem to work acceptable well on some phone but others continue sending 'keep turning' telegrams even after the MotionEvent.ACTION_UP event has been processed and no more data are being send.
I assume that this is caused by some internal buffers that cache the transmit data and continue sending until the buffer is empty.
Simple questions:
Is there a way to purge the BT stream transmit buffer to stop all data transfer immediately?
Or can I get the fill level of the transmit buffer in which case I would not put anything more than about 2 telegrams into it?
Or is there a way to specify the buffer size when opening the stream?
Searching the net, I was not able to find anything that talks about BT stream buffer size of buffer management.
And Yes, I have implemented read and write functions as threads and I do not have any problems in reading all telegrams, and I do not need to deliver telegrams in real time but I should be able to stop sending 'keep turning' telegrams within about 50 to 100ms.
Any hints are very welcome.

I am sorry that I did not add the code, I thought it may not be necessary as it is straight forward as:
#Override
public boolean onTouch(final View v,MotionEvent event) {
int eventAction = event.getAction();
switch (eventAction) {
case MotionEvent.ACTION_DOWN:
if (v == btnUp || v == btnDown) {
// Start a thread that sends the goUP or DOWN command every 10 ms until
// btnUp released
tvCounter.setText("----");
action_touched = true;
new Thread(new Runnable() {
#Override
public void run() {
int counter = 1;
// Disable heart beat
ServiceRequest.send(EnRequest.REQ_SET_HEARTBEAT,0);
// Send GoUp command plus a wrapping counter byte every nn ms
// until the button is released
while (action_touched) {
try {
setDeadmanMove(v==btnUp,counter);
Thread.sleep(20);
++counter;
}
catch (InterruptedException ex) {
action_touched = false;
}
catch (Exception ex) {
action_touched = false;
}
}
// Send a STOP command
setDeadmanStop();
// Enable heart beat again
ServiceRequest.send(EnRequest.REQ_SET_HEARTBEAT,1);
// We are done
}
}).start();
}
break;
case MotionEvent.ACTION_UP:
// Stop Thread
action_touched = false;
break;
}
return true;
}
The snipped below is part of the communication class that manages the Bluetooth serial communication.
public void btWrite(DeviceRecord message) {
if (runBTreceiver) {
if (message.isValidRecord()) {
try {
lock.lock();
++lockCounter;
mmBufferedOut.write(message.getFullRecord());
mmBufferedOut.flush();
}
catch (IOException e) {
if (GlobalData.isDebugger) Log.i(TAG, "Failed sending " + message + " " + e.getMessage());
ServiceResponse.send(EnEvent.EVT_BT_RECEIVER_ERROR, "Error data send: " + e.getMessage());
resetConnection();
runBTreceiver=false;
}
finally {
--lockCounter;
lock.unlock();
}
}
}
}
The code snipped that allocates and opens the Bluetooth connection
try {
// Set up a pointer to the remote node using it's address.
BluetoothDevice device = myBluetoothAdapter.getRemoteDevice(myBluetoothMacId);
if (device != null)
{
// Two things are needed to make a connection:
// A MAC address, which we got above.
// A Service ID or UUID. In this case we are using the
// UUID for SPP.
try {
myBluetoothSocket = device.createRfcommSocketToServiceRecord(GlobalData.MY_UUID);
}
catch (IOException e) {
sendEventStatus(EnEvent.EVT_BTADAPTER_FAIL,
String.format(GlobalData.rString(R.string.srv_failcrt),BTERROR_CREATE,e.getMessage()));
}
// Establish the connection. This will block until it connects or
// timeout?
try {
if (! myBluetoothSocket.isConnected()) {
myBluetoothSocket.connect();
}
}
catch (IOException e) {
try {
Log.e("","trying fallback...");
myBluetoothSocket =(BluetoothSocket) device.getClass().getMethod("createRfcommSocket", new Class[] {int.class}).invoke(device,1);
myBluetoothSocket.connect();
}
catch (IOException e2) {
sendEventStatus(EnEvent.EVT_BTADAPTER_FAIL,e2.getMessage());
}
}
}
else {
sendEventStatus(EnEvent.EVT_BTADAPTER_FAIL,
String.format(GlobalData.rString(R.string.srv_failcrt),BTERROR_DEVICE,"getRemoteDevice failed"));
}
}
catch (Exception e) {
sendEventStatus(EnEvent.EVT_BTADAPTER_FAIL, e.getMessage());
return;
}
InputStream tmpIn = null;
OutputStream tmpOut = null;
mmSocket = socket;
// Get the input and output streams, using temp objects because
// member streams are final
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
}
catch (IOException e) {
ServiceResponse.send(EnEvent.EVT_ERROR, GlobalData.rString(R.string.srv_failcst) + e.getMessage());
resetConnection();
runBTreceiver=false;
}
mmInStream = tmpIn;
// mmOutStream = tmpOut;
mmBufferedOut = new BufferedOutputStream(tmpOut,80);
// Initial request
btWrite(new DeviceRecord(0, 4));
I have never discovered any problems sending and receiving data via this code. All records are sent and received properly. Only problem was that I am unable to purge the transmit buffer at the moment the operate button was released.
To overcome this problem, I have changed the protocol in such a way, that only a single 'keep turning' telegram is send at a time, the next telegram will be send after a response from the other end (sort of handshaking), the program then continue to run this ping/pong until the button is released.
This method works quite well as the transmit buffer will never hold more than one telegram at a time.
the mentioned problem is solved though but I still have no clue of whether it would be possible to purge a transmit buffer

Android Serversocket does not seem to accept connections on emulators

I've been trying to implement a simple socket communication between two Android emulators but just can't seem to get it.
My server:
public void run() {
if (SERVERIP != null) {
try {
serverStatus.setText("My IP: " + SERVERIP);
serverSocket = new ServerSocket(6798);
serverStatus.setText("ServerSocket Created");
}
catch(Exception e) {
e.printStackTrace();
}
try {
while (true) {
serverStatus.setText("waiting for client");
Socket client = serverSocket.accept();
serverStatus.setText("Connected.");
BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
String line = in.readLine();
serverStatus.setText(line);
in.close();
client.close();
}
}
catch(Exception e) {
e.printStackTrace();
}
}
else
serverStatus.setText("Couldn't detect internet connection.");
}
My Client:
try {
InetAddress ina = InetAddress.getByName("10.0.2.2");
socket = new Socket(ina, 6789);
}
catch (Exception e) {
e.printStackTrace();
}
try {
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
out.println("Hey Server!");
dispText.setText("sent");
}
catch (Exception e) {
e.printStackTrace();
}
The Client side goes on to display the message "sent" however the Server does not move beyond "waiting for client" (stuck on the blocking accept()).
I've used telnet on my Windows machine to redirect port 6789 to 6798 on the server emulator's console. I've also tried turning off my firewall and the other suggestions posted on the similar questions asked here. Please help as just can't seem to get it and feel like I'm making a very stupid mistake.
Also, can anyone please tell me how it is possible for the Client to move beyond the Socket creation code line if the Server is still stuck on accept(). Or, does it not matter to the client that the Server isn't responding as long as it is listening on the port??

Android emulators are placed behind a virtual firewall/router by design, and cannot see each other, even when they are on the same network. The "Using Network Redirection", as well as "Interconnecting Emulator Instances" part of Google's doc on the emulator explains how to communicate with an emulator instance.
As for your last question. Use the empty constructor for socket, and then use the connect call with a specified timeout.

Android TCP app hanging on inStream.readline()

This is a continuation of this question because it my orginal question was answered, but it did not solve the bug.
Question:
How do I fix the code hanging on this line inStream.readline()
My Intent:
This is in a thread that will loop through checking if there is an outMessage, if there is, it will send the message.
Next it will check it if there is anything in the in-stream, if there is, it will send it to the handler in my main activity.
Lastly, it will sleep for 1 second, then check again.
This should allow me to read/write multiple times without needing to close and open the socket.
Problem:
It is reading and writing better, but still not working properly
What is happening now:
If outMessage is initialized with a value, upon connection with the server, the socket:
writes and flushes the value (server receives & responds)
updates value of outMessage (to null or to "x" depending on how i have it hard-coded)
reads and shows the response message from the server
re-enters for the next loop
IF i set outMessage to null, it skips over that if statements correctly then hangs; otherwise, if i set outMessage to a string (lets say "x"), it goes through the whole if statement, then hangs.
The code it hangs on is either of the inStream.readline() calls (I currently have one commented out).
Additional info:
- once connected, I can type in the "send" box, submit (updates the outMessage value), then disconnect. Upon re-connecting, it will read the value and do the sequence again until it get stuck on that same line.
Changes since the referenced question:
- Made outMessage and connectionStatus both 'volatile'
- added end-of-line delimiters in neccesary places.
Code:
public void run() {
while (connectionStatus != TCP_SOCKET_STATUS_CONNECTED) {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
while (connectionStatus == TCP_SOCKET_STATUS_CONNECTED) {
try {
if (outMessage != null){
OutStream.writeBytes(outMessage + "\n");
OutStream.flush();
sendMessageToAllUI(0, MAINACTIVITY_SET_TEXT_STATE, "appendText" , "OUT TO SERVER: " + outMessage);
outMessage = "x";
}
Thread.sleep(100);
// if (InStream.readLine().length() > 0) {
String modifiedSentence = InStream.readLine();
sendMessageToAllUI(0, MAINACTIVITY_SET_TEXT_STATE, "appendText" , "IN FROM SERVER: " + modifiedSentence);
// }
Thread.sleep(1000);
} catch (IOException e) {
connectionLost();
break;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
The thread that makes the socket:
public void run() {
setName("AttemptConnectionThread");
connectionStatus = TCP_SOCKET_STATUS_CONNECTING;
try {
SocketAddress sockaddr = new InetSocketAddress(serverIP, port);
tempSocketClient = new Socket(); // Create an unbound socket
// This method will block no more than timeoutMs. If the timeout occurs, SocketTimeoutException is thrown.
tempSocketClient.connect(sockaddr, timeoutMs);
OutStream = new DataOutputStream(tempSocketClient.getOutputStream());
InStream = new BufferedReader(new InputStreamReader(tempSocketClient.getInputStream()));
socketClient = tempSocketClient;
socketClient.setTcpNoDelay(true);
connected();
} catch (UnknownHostException e) {
connectionFailed();
} catch (SocketTimeoutException e) {
connectionFailed();
} catch (IOException e) {
// Close the socket
try {
tempSocketClient.close();
} catch (IOException e2) {
}
connectionFailed();
return;
}
}
Server:
public static void main(String[] args) throws IOException {
String clientSentence;
String capitalizedSentence;
try {
ServerSocket welcomeSocket = new ServerSocket(8888);
SERVERIP = getLocalIpAddress();
System.out.println("Connected and waiting for client input!\n Listening on IP: " + SERVERIP +"\n\n");
Socket connectionSocket = welcomeSocket.accept();
BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());
while(true)
{
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
clientSentence = inFromClient.readLine();
System.out.println("clientSentance == " + clientSentence);
String ip = connectionSocket.getInetAddress().toString().substring(1);
if(clientSentence != null)
{
System.out.println("In from client ("+ip+")("+ System.currentTimeMillis() +"): "+clientSentence);
capitalizedSentence = clientSentence.toUpperCase() + '\n';
outToClient.writeBytes(capitalizedSentence + '\n');
System.out.println("Out to client ("+ip+"): "+capitalizedSentence);
}
}
} catch (IOException e) {
//if server is already running, it will not open new port but instead re-print the open ports information
SERVERIP = getLocalIpAddress();
System.out.println("Connected and waiting for client input!\n");
System.out.println("Listening on IP: " + SERVERIP +"\n\n");
}
}
Thanks in advance!
Edits:
added the server code after updating
I tried messing around with setting the SoTimout for the socket but took that back out

Your server is specifically designed to receive exactly one line from a client and send exactly one line back. Look at the code:
while (true) {
Socket connectionSocket = welcomeSocket.accept();
BufferedReader inFromClient = new BufferedReader(
new InputStreamReader(connectionSocket.getInputStream()));
DataOutputStream outToClient = new DataOutputStream(
connectionSocket.getOutputStream());
clientSentence = inFromClient.readLine();
String ip = connectionSocket.getInetAddress().toString()
.substring(1);
System.out.println("In from client (" + ip + "): "
+ clientSentence);
if (clientSentence != null) {
capitalizedSentence = clientSentence.toUpperCase() + '\n';
System.out.println("Out to client (" + ip + "): "
+ capitalizedSentence);
outToClient.writeBytes(capitalizedSentence + "\n");
}
Notice that inside the loop it accepts a new connection, reads exactly one line, and then writes exactly one line. It doesn't close the connection. It doesn't sanely end the conversation. It just stops reading.
A client that worked with this server would have to connect, send exactly one line, read exactly one line back, and then the client would have to close the connection. Your client doesn't do that. Why? Because you had no idea that's what you had to do. Why? Because you had no design ... no plan.
So that's your specific issue. But please, let me urge you to take a huge step back and totally change your approach. Before you write a single line of code, please actually design and specify a protocol at the byte level. The protocol should say what data is sent, how messages are delimited, who sends when, who closes the connection, and so on.
Otherwise, it's impossible to debug your code. Looking at the server code above, is it correct? Well, who knows. Because it's unclear what it's supposed to do. When you wrote the client, you assumed the server behaved one way. Was that assumption valid? Is the server broken? Who knows, because there's no specification of what the server is supposed to do.

You need to check if there is data available:
if (InStream.available > 0) {
String modifiedSentence = InStream.readLine();
sendMessageToAllUI(0, MAINACTIVITY_SET_TEXT_STATE, "appendText" , "IN FROM SERVER: " + modifiedSentence);
}
But to be honest, even that is not ideal because you have no gurantee that the eond-of-line will have been received. If the server sends a few bytes but never sends the end-of-line then you will still be blocking forever. Production socket code should never rely on readLine but instead read into a buffer and check that buffer for end-of-line (or whatever criteria your protocol needs).
Didn't read closely enough, I thought InStream was an InputStream instance. InputStream has available. InputStreamReader has ready (which in turn calls InputStream.available. As long as you keep a refernce to either of these then you can see if data is available to be read.

Data being lost between Android device and python server using TCP

I'm somewhat new to network programming and am having some trouble. I am creating a JSON object on an Android device, connecting to a python server via TCP, and sending the JSON string. The connection gets accepted, but I keep losing the end of the string, so
json.loads(json_string)
is failing.
Here is the relevant Android code:
private class Worker implements Runnable
{
#Override
public void run()
{
//create the network socket
try
{
socket = new Socket(address, 4242);
Log.i(TAG, "timeout: " + socket.getSoTimeout());
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
packets = new ArrayList<JSONObject>();
for (jobs.moveToFirst(); jobs.isAfterLast() == false; jobs.moveToNext())
{
String jobName = jobs.getString(jobs.getColumnIndex(JobMetaData.JobTableMetaData.JOB));
Uri.Builder updated = new Uri.Builder();
updated.scheme("content");
updated.authority(JobMetaData.AUTHORITY);
updated.appendPath(jobName);
updated.appendPath("member");
updated.appendPath(JobMetaData.MemberTableMetaData.CHANGED);
updated.appendPath("true");
Cursor changed = getContentResolver().query(updated.build(), null, null, null, null);
Log.d(TAG, "number of members " + changed.getCount());
//create a JSON object out of the editable properties
for (changed.moveToFirst(); changed.isAfterLast() == false; changed.moveToNext())
{
JSONObject json = new JSONObject();
for (String att : changed.getColumnNames())
{
if (ListMetaData.validAtts.contains(att))
{
try
{
json.put(att, changed.getString(changed.getColumnIndex(att)));
}
catch (JSONException e)
{
// TODO Auto-generated catch block
Log.d(TAG, "JSON exception in DatagramService");
e.printStackTrace();
}
}
}
//include the GUID and job name
//for identification
try
{
json.put(JobMetaData.MemberTableMetaData.GUID,
changed.getString(changed.getColumnIndex(JobMetaData.MemberTableMetaData.GUID)));
json.put(JobMetaData.JobTableMetaData.JOB, jobName);
}
catch (JSONException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
packets.add(json);
}
changed.close();
}
Log.d(TAG, "entering send loop");
try
{
out = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
out.flush();
}
catch (IOException e1)
{
// TODO Auto-generated catch block
e1.printStackTrace();
}
for (JSONObject packet : packets)
{
Log.d(TAG, "supposedly sending");
try
{
//now write the data
Log.d(TAG, "packet string: " + packet.toString());
out.write(packet.toString());
out.flush();
}
catch (IOException e)
{
}
}
try
{
out.write("Done");
out.flush();
out.close();
} catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
stopSelf();
}
And the test server that I am using (written in python):
#!/usr/bin/env python
import SocketServer
import json
class MemberUpdateHandler(SocketServer.BaseRequestHandler):
def setup(self):
print self.client_address, "connected"
def handle(self):
while True:
self.JSONString = self.request.recv(8192).strip()
if self.JSONString == "Done":
return
self.handleJSON()
self.update()
def handleJSON(self):
JSONMember = json.loads(self.JSONString)
print "GUID:", JSONMember['ManufacturingGUID']
print "Weight:", JSONMember['Weight']
def update(self):
print "do something here"
if __name__ == "__main__":
ADDRESS = ''
PORT = 4242
HOST = (ADDRESS, PORT)
s = SocketServer.ThreadingTCPServer(HOST, MemberUpdateHandler)
s.serve_forever()
Here is the string that is being sent (it is long):
{"DetailCheckedBy":"","SketchRight":"","DetailLength":"142.75","DetailedDate":"**NOT SET**","EngineerVerifiedBothConns":"False","HoldStatus":"Not held","RevisionLevel":"No Revision","MemberNumber":"28","RequestVerifySectionSize":"False","TieForcesRight":"False","InputBy":"","IFCFinishDate_4":"**NOT SET**","IFCFinishDate_5":"**NOT SET**","Weight":"438.408","IFCTaskUID_1":"","IFCFinishDate_1":"**NOT SET**","ErectorOrder":"","IFCFinishDate_2":"**NOT SET**","IFCFinishDate_3":"**NOT SET**","IFCTaskUID_4":"","IFCTaskUID_5":"","IFCTaskUID_2":"","SketchLeft":"","IFCTaskUID_3":"","ErectorSequences":"","ReasonRejected":"","MemberCategory":"","EngineerVerifiedLeftConn":"False","BarcodeId":"","ManufacturingGUID":"42bbf9cc-52da-4712-a5fc-e37c5a544c14","aess":"False","FabricationComplete":"**NOT SET**","UserComment2":"","UserComment3":"","LoadNumber":"","UserComment1":"","ErectionBolted":"**NOT SET**","RequestVerifyLength":"False","RequestVerifyGrade":"False","Painted":"False","HeatCertNumber":"","Route1Description":"","IsExisting":"No","ReceivedFromApproval":"**NOT SET**","BackCheckedBy":"","BatchNumber":"","CostCodeReference":"","PONumber":"","Piecemark":"B_25","ReleasedForFabrication":"**NOT SET**","MemberDescription":"BEAM","EngineerVerifiedMemberReady":"False","IFCTaskName_2":"","IFCTaskName_1":"","IFCTaskName_4":"","RequestVerifyMemberPosition":"False","IFCTaskName_3":"","Erected":"**NOT SET**","RevisionCheckedBy_3":"","IFCTaskName_5":"","RevisionCheckedBy_2":"","RevisionCheckedBy_1":"","EngineerVerifiedLeftComments":"","RequestVerifyLeftConnMaterial":"False","RequestEngineerVerify":"False","RevisionCheckedDate_3":"**NOT SET**","RevisionCheckedDate_2":"**NOT SET**","RevisionCheckedDate_1":"**NOT SET**","EngineerVerifiedLength":"False","BackCheckedDate":"**NOT SET**","SubmittedForApproval":"**NOT SET**","EngineerVerifiedSpecial":"False","CostCodeDescription":"","IFCStartDate_5":"**NOT SET**","TieForcesLeft":"False","Fireproofed":"False","ErectorAvailable":"False","RequestVerifyRightConnMaterial":"False","DetailCheckedDate":"**NOT SET**","ErectorNonSteelSupported":"False","BeamPent":"False","StockStatus":"","Sequence":"1","RequestVerifyLeftLoad":"False","DetailFinalCheckDate":"**NOT SET**","ErectorMemberPlaced":"**NOT SET**","InstanceStatus":"","EngineerVerifiedRightConn":"False","DateReceived":"**NOT SET**","MemberType":"Beam","ModelCheckDate":"**NOT SET**","ReasonForHold":"","EngineerVerifiedRightComments":"","ReceivedOnJobSite":"**NOT SET**","RequestVerifyRightLoad":"False","CostCodePrice":"0.0","NestStatus":"","DateDue":"**NOT SET**","ShopSequence":"","EngineerVerifiedSectionSize":"False","ActualLength":"144","InputDate":"**NOT SET**","ErectorCity":"Unknown","EngineerVerifiedSpecial_comments":"","Route4Description":"","EngineerVerifiedGrade":"False","RightLocation":"0.0xx144.0xx156.0xx","IFCFinishTime_2":"","IFCFinishTime_1":"","IFCFinishTime_4":"","Route3Description":"","IFCFinishTime_3":"","LoadStatus":"","ErectorLongitude":"","DateModelCompleted":"61299957600000","Grade":"##SEKRIT KODE!!##","IFCFinishTime_5":"","Route2Description":"","RequestVerifyCamber":"False","ProjectedFabricationComplete":"**NOT SET**","DetailedBy":"","DetailFinalCheckBy":"","Description":"W8x35","ProjectedShippedDate":"**NOT SET**","NestName":"","IFCStartDate_2":"**NOT SET**","IFCStartTime_1":"","IFCStartDate_1":"**NOT SET**","IFCStartDate_4":"**NOT SET**","IFCStartDate_3":"**NOT SET**","IFCStartTime_5":"","IFCStartTime_4":"","IFCStartTime_3":"","DateHeld":"**NOT SET**","IFCStartTime_2":"","LeftLocation":"0.0xx0.0xx156.0xx","Job":"Mobile_x_x_x_x_Demo_x_x_x_x_IN_x_x_x_x_2011","SpecialCutWeld":"False","RejectedBy":"","ErectionWelded":"**NOT SET**","RequestVerifyRightConnConfig":"False","Vendor":"","PackageNumber":"","RejectedByErector":"**NOT SET**","ModelCheckedBy":"","ApprovalStatus":"Not reviewed","RequestVerifyLeftConnConfig":"False","ErectorLatitude":"","LotName":"","ActualShipDate":"**NOT SET**","NestId":""}
This is the error I get from the python server:
ValueError: Unterminated string starting at: line 1 column 1435 (char 1435)
which means that the string has been truncated to:
{"DetailCheckedBy":"","SketchRight":"","DetailLength":"142.75","DetailedDate":"**NOT SET**","EngineerVerifiedBothConns":"False","HoldStatus":"Not held","RevisionLevel":"No Revision","MemberNumber":"28","RequestVerifySectionSize":"False","TieForcesRight":"False","InputBy":"","IFCFinishDate_4":"**NOT SET**","IFCFinishDate_5":"**NOT SET**","Weight":"438.408","IFCTaskUID_1":"","IFCFinishDate_1":"**NOT SET**","ErectorOrder":"","IFCFinishDate_2":"**NOT SET**","IFCFinishDate_3":"**NOT SET**","IFCTaskUID_4":"","IFCTaskUID_5":"","IFCTaskUID_2":"","SketchLeft":"","IFCTaskUID_3":"","ErectorSequences":"","ReasonRejected":"","MemberCategory":"","EngineerVerifiedLeftConn":"False","BarcodeId":"","ManufacturingGUID":"42bbf9cc-52da-4712-a5fc-e37c5a544c14","aess":"False","FabricationComplete":"**NOT SET**","UserComment2":"","UserComment3":"","LoadNumber":"","UserComment1":"","ErectionBolted":"**NOT SET**","RequestVerifyLength":"False","RequestVerifyGrade":"False","Painted":"False","HeatCertNumber":"","Route1Description":"","IsExisting":"No","ReceivedFromApproval":"**NOT SET**","BackCheckedBy":"","BatchNumber":"","CostCodeReference":"","PONumber":"","Piecemark":"B_25","ReleasedForFabrication":"**NOT SET**","MemberDescription":"BEAM","EngineerVerifiedMemberReady":"False","IFCTaskName_2":"","IFCTaskName_1":"","IFCTaskName_4":"","RequestVerifyMemberPosition":"False","IFCTaskName_3":"","Erected":"**NOT SET**","RevisionCheckedBy_3":"","IFCTaskName_
Any help would be greatly appreciated. Thanks in advance.
UPDATE:
I have updated the code to reflect my tinkering. The string received by the server is now
{"DetailCheckedBy":"","SketchRight":"","DetailLength":"142.75","DetailedDate":"**NOT SET**","EngineerVerifiedBothConns":"False","HoldStatus":"Not held","RevisionLevel":"No Revision","MemberNumber":"28","RequestVerifySectionSize":"False","TieForcesRight":"False","InputBy":"","IFCFinishDate_4":"**NOT SET**","IFCFinishDate_5":"**NOT SET**","Weight":"438.408","IFCTaskUID_1":"","IFCFinishDate_1":"**NOT SET**","ErectorOrder":"","IFCFinishDate_2":"**NOT SET**","IFCFinishDate_3":"**NOT SET**","IFCTaskUID_4":"","IFCTaskUID_5":"","IFCTaskUID_2":"","SketchLeft":"","IFCTaskUID_3":"","ErectorSequences":"","ReasonRejected":"","MemberCategory":"","EngineerVerifiedLeftConn":"False","BarcodeId":"","ManufacturingGUID":"42bbf9cc-52da-4712-a5fc-e37c5a544c14","aess":"False","FabricationComplete":"**NOT SET**","UserComment2":"","UserComment3":"","LoadNumber":"","UserComment1":"","ErectionBolted":"**NOT SET**","RequestVerifyLength":"False","RequestVerifyGrade":"False","Painted":"False","HeatCertNumber":"","Route1Description":"","IsExisting":"No","ReceivedFromApproval":"**NOT SET**","BackCheckedBy":"","BatchNumber":"","CostCodeReference":"","PONumber":"","Piecemark":"B_25","ReleasedForFabrication":"**NOT SET**","MemberDescription":"BEAM","EngineerVerifiedMemberReady":"False","IFCTaskName_2":"","IFCTaskName_1":"","IFCTaskName_4":"","RequestVerifyMemberPosition":"False","IFCTaskName_3":"","Erected":"**NOT SET**","RevisionCheckedBy_3":"","IFCTaskName_5":"","RevisionCheckedBy_2":"","RevisionCheckedBy_1":"","EngineerVerifiedLeftComments":"","RequestVerifyLeftConnMaterial":"False","RequestEngineerVerify":"False","RevisionCheckedDate_3":"**NOT SET**","RevisionCheckedDate_2":"**NOT SET**","RevisionCheckedDate_1":"**NOT SET**","EngineerVerifiedLength":"False","BackCheckedDate":"**NOT SET**","SubmittedForApproval":"**NOT SET**","EngineerVerifiedSpecial":"False","CostCodeDescription":"","IFCStartDate_5":"**NOT SET**","TieForcesLeft":"False","Fireproofed":"False","ErectorAvailable":"False","RequestVerifyRightConnMaterial":"False","DetailCheckedDate":"**NOT SET**","ErectorNonSteelSupported":"False","BeamPent":"False","StockStatus":"","Sequence":"1","RequestVerifyLeftLoad":"False","DetailFinalCheckDate":"**NOT SET**","ErectorMemberPlaced":"**NOT SET**","InstanceStatus":"","EngineerVerifiedRightConn":"False","DateReceived":"**NOT SET**","MemberType":"Beam","ModelCheckDate":"**NOT SET**","ReasonForHold":"","EngineerVerifiedRightComments":"","ReceivedOnJobSite":"**NOT SET**","RequestVerifyRightLoad":"False","CostCodePrice":"0.0","NestStatus":"","DateDue":"**NOT SET**","ShopSequence":"","EngineerVerifiedSectionSize":"False","ActualLength":"144","InputDate":"**NOT SET**","ErectorCity":"Unknown","EngineerVerifiedSpecial_comments":"","Route4Description":"","EngineerVerifiedGrade":"False","RightLocation":"0.0xx144.0xx156.0xx","IFCFinishTime_2":"","IFCFinishTime_1":"","IFCFinishTime_4":"","Route3Description":"","IFCFinishTime_3":"","LoadStatus":"","ErectorLongitude":"","DateModelCompleted":"61299957600000","Grade":"##SEKRIT KODE!!##","IFCFinishTime_5":"","Route2Description":"","RequestVerifyCamber":"False","ProjectedFabricationComplete":"**NOT SET**","DetailedBy":"","DetailFinalCheckBy":"","Description":"W8x35","ProjectedShippedDate":"**NOT SET**","NestName":"","IFCStartDate_2":"**NOT SET**","IFCStartTime_1":"","IFCStartDate_1":"**NOT SET**","IFCStartDate_4":"**NOT SET**","IFCStartDate_3":"**NOT SET**","IFCStartTime_5":"","IFCStartTime_4":"","IFCStartTime_3":"","DateHeld":"**NOT SET**","IFCStartTime_2":"","LeftLocation":"0.0xx0.0xx156.0xx","Job":"Mobile_x_x_x_x_Demo_x_x_x_x_IN_x_x_x_x_2011","SpecialCutWeld":"False","RejectedBy":"","ErectionWelded":"**NOT SET**","RequestVerifyRightConnConfig":"False","Vendor":"","PackageNumber":"","RejectedByErector":"**NOT SET**","ModelCheckedBy":"","ApprovalStatus":"Not reviewed","RequestVerifyLeftConnConfig":"False","ErectorLatitude":"","LotName":"","ActualShipDate":"**NOT SET**","NestId":""}Done
followed by a mess of whitespace. Enough that gedit has trouble loading it all. One step forward two steps back. :/

sizeof(int) may not be the same on both devices. So you probably should hardcode something if you want to pass a binary integer.
If you evaluate int('\001\002\003\004\005\006\007\010'), you're unlikely to get what you want, and I believe that's close to what you're doing in your Python code. For one thing, the endianness of the two devices might be different, and for another, int() wants to evaluate ASCII or some other encoding, not raw endian-dependent integers.
On the python side, you might find this useful:
http://stromberg.dnsalias.org/~strombrg/bufsock.html
I'm not sure about the out.write() you're using, but at the lower level of send(), there's no guarantee that your entire buffer will be written in a single send() - it's allowed to stop early and just return how much was sent. Hopefully, java protects you from that detail the way bufsock does for python.

Why are you "assuming" that the string has been truncated? print it and see what it actually is.
Also, the string that is being sent (as you posted it) is not enclosed in {}, which means it is not proper JSON... I tried to copy/paste it in the interpreter, this raises a ValueError:
ValueError: Extra data: line 1 column 17 - line 1 column 3952 (char 17 - 3952)
I enclosed it in {} and it worked. You should try to see what the string you are receiving actually is on the python side, and then you can really see what's happening. I assume also, that since you are seeing the "Done" sent, then the content should have been sent completely.