Develop Reference

The server is sending data through the socket, but the client is not receving it (Java)

I am writing a file storage and transfer system using Java. Here's the code on the client side to receive a file:
public static void receiveFile(Socket socket) throws IOException{
String fileLocation="/home/limafoxtrottango/Downloads/receivedFile";
int bytesRead=0;
int current = 0;
FileOutputStream fileOutputStream = null;
BufferedOutputStream bufferedOutputStream = null;
try {
// receive file
byte [] byteArray = new byte [60022386];
System.out.println("Waiting to receive a file...");
//reading file from socket
InputStream inputStream = socket.getInputStream();
fileOutputStream = new FileOutputStream(fileLocation);
bufferedOutputStream = new BufferedOutputStream(fileOutputStream);
bytesRead = inputStream.read(byteArray,0,byteArray.length); //copying file from socket to byteArray
current = bytesRead;
do {
bytesRead =inputStream.read(byteArray, current, (byteArray.length-current));
if(bytesRead >= 0) current += bytesRead;
} while(bytesRead > -1);
bufferedOutputStream.write(byteArray, 0 , current); //writing byteArray to file
bufferedOutputStream.flush(); //flushing buffers
System.out.println("File " + fileLocation + " downloaded ( size: " + current + " bytes read)");
} catch(SocketException e){
System.out.println("Some error occured");
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally {
if (fileOutputStream != null) fileOutputStream.close();
if (bufferedOutputStream != null) bufferedOutputStream.close();
if (socket != null) socket.close();
}
}
While receiving a file, I get the following error:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException
at java.lang.System.arraycopy(Native Method)
at java.io.BufferedOutputStream.write(BufferedOutputStream.java:128)
at Test.receiveFile(Test.java:211)
at Test.main(Test.java:70)
Note: The error is in the following line of the code:
bufferedOutputStream.write(byteArray, 0 , current);
After debugging, I found-out that the client does not have any data in it's input stream, and hence, the read() method always returns -1 (eof). But the server is sending the file successfully.
Here is the code for the server:
public static void sendFile(Socket socket, String fileLocation)
{
FileInputStream fileInputStream = null;
BufferedInputStream bufferedInputStream = null;
OutputStream outputStream = null;
File file = new File (fileLocation);
byte [] byteArray = new byte [(int)file.length()];
try {
socket=new Socket(socket.getInetAddress(),port_no);
fileInputStream = new FileInputStream(file);
bufferedInputStream = new BufferedInputStream(fileInputStream);
bufferedInputStream.read(byteArray,0,byteArray.length); // copied file into byteArray
//sending file through socket
outputStream = socket.getOutputStream();
System.out.println("Sending " + fileLocation + "( size: " + byteArray.length + " bytes)");
outputStream.write(byteArray,0,byteArray.length); //copying byteArray to socket
outputStream.flush(); //flushing socket
System.out.println("Done sending!");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
And here is my call to the above method:
sendFile(clientSocket, "/home/limafoxtrottango/Downloads/serverDownloads/"+sender);
The thing is that the server is successfully writing the byte into the stream, but the client doesn't seem to have any data in it's input stream.

https://docs.oracle.com/javase/7/docs/api/java/io/InputStream.html#read(byte[],%20int,%20int)
inputStream.read(byteArray,0,byteArray.length); may return -1 in some cases as given in documentation above. Please cater for such situations.
In addition, I would suggest to use solution given here for both client and server: Efficient way to write InputStream to a File in Java (Version 6)
Client code:
final Path destination = Paths.get(fileLocation);
try (
final InputStream in = socket.getInputStream();
) {
Files.copy(in, destination);
}
Server code:
try (
final InputStream in = new FileInputStream(fileLocation);
) {
Files.copy(in, socket.getOutputStream());
}
Kind regards,
Bala

The server isn't sending anything, contrary to your title. It is closing the connection immediately, so bytesRead is initially -1 and never changes, and you aren't defending against that, so you get the ArrayIndexOutOfBoundsException.
However in the code you posted, the server is sending something but never closing the socket, which is another bug you need to fix. It is also ignoring the count returned by FileInputStream.read() and assuming it filled the buffer, which isn't part of the specification.
So either this is not the real server code or you are connecting to something else, or the server got an IOException that you haven't mentioned.
It's curious that you use two different pieces of code for copying. The standard way to copy a stream in Java is this:
char buffer = new char[8192]; // or whatever size you prefer > 0
int count;
while ((count = in.read(buffer)) > 0)
{
out.write(buffer, 0, count);
}
Use this at both ends. There is no need for heroically sized buffers, or buffers the size of the file, or assuming that the file size fits into an int.

java file transfer socket write error

I'm working on a client-server file transfer project, I've almost completed my tests on localhost but today got an error below, here are the source codes of client and server:
Client side
public class Client {
public static void main(String args[]) {
String receiverIP = null;
int serverPort = 0;
receiverIP = args[0];
serverPort = Integer.parseInt(args[1]);
String fileToSend = args[2];
byte[] aByte = new byte[1];
int bytesR;
Socket clientSocket = null;
BufferedOutputStream bos = null;
InputStream is = null;
try {
clientSocket = new Socket(receiverIP, serverPort);
bos = new BufferedOutputStream(clientSocket.getOutputStream());
is = clientSocket.getInputStream();
} catch (IOException ex) {
ex.printStackTrace();
}
if (is != null) {
FileOutputStream fos = null;
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try {
File myFile = new File( fileToSend );
System.out.println("The file chosen is being sent...");
byte[] mybytearray = new byte[(int) myFile.length()];
FileInputStream fis = null;
try {
fis = new FileInputStream( myFile );
} catch (FileNotFoundException ex) {
ex.printStackTrace();
}
try {
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(mybytearray, 0, mybytearray.length);
bos.write(mybytearray, 0, mybytearray.length);
bis.close();
return;
}catch (IOException ex) {
ex.printStackTrace();
}
File file = new File("C:\\copy.jpg");
fos = new FileOutputStream( file );
bos = new BufferedOutputStream(fos);
bytesR = is.read(aByte, 0, aByte.length);
do {
baos.write(aByte);
bytesR = is.read(aByte);
} while (bytesR != -1);
System.out.println("File transfer successful");
bos.write(baos.toByteArray());
bos.flush();
bos.close();
clientSocket.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}
Server side
public class Server {
public static void main(String args[]) {
while (true) {
ServerSocket welcomeSocket = null;
BufferedOutputStream ToClient = null;
try {
welcomeSocket = new ServerSocket(3249);
System.out.println("The port " + welcomeSocket.getLocalPort() + " is opened and ready for use.");
Socket connectionSocket = welcomeSocket.accept();
ToClient = new BufferedOutputStream(connectionSocket.getOutputStream());
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}
here is the error I get
The file chosen is being sent...
java.net.SocketException: Connection reset by peer: socket write error
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(Unknown Source)
at java.net.SocketOutputStream.write(Unknown Source)
at java.io.BufferedOutputStream.write(Unknown Source)
at Client.main(Client.java:44)
java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at Client.main(Client.java:55)
I'm nearly sure this error is not about closing the server socket before all data is transmitted, and about the reading and writing process on the bytearray but all my fix attempts were in vain, maybe I've misplaced the streams so they do not work as intended, (the copy.jpg file is created but not getting any streams) any help would be appreciated
edit: I forgot to mention, currently I'm using a wireless internet connection and I've read a little about socket porgramming that mentions wireless networks are unreliable to test on

Your server side does not wait for data to be received. It accepts the connection and then continues with the next loop cycle immediately. This causes your initial server socket and socket to client to be garbage-collected and thus closed.
You can verify this behaviour by using telnet, which is very handy when it comes to checking servers in general. Open a command prompt on the server machine (cmd or a console) and run this command to connect to your server:
telnet localhost 3249
You will see that it connects and then gets disconnected almost immediately, just like your own client application.
The solution is that additionally to the code for accepting the connection on the server side, you need to write code there for receiving the data.
Moreover, you should put the creation of the server socket in front of the loop instead of inside the loop. You need to create the server socket only once and you can then accept arbitrarily many connections through it. Opening the server socket more than once will fail, because the port is still occupied (freeing the port often takes a few seconds in some operating systems, even when the previous server socket has been closed).

java tcp server to android device

i am trying to make a java server that will send images stored in a database to android device.
for now am trying with simple image that stored on the hard disk for the server to send.
my question is can i send an image from java server as a byte array to android via TCP sockets.

Yes, you can, using TCP sockets.
Read the file as bytes and send it as bytes, don't try to load it as a BufferedImage.
Then, on the receiving end, use a function that allows you to load an image from an array of bytes.

Sure, you can, but you will need to invent your own protocol for that. You may find using HTTP more, either setting up a web-server like Tomcat with your application deployed there, or use something embedded like Jetty

The fastest and easiest approach for sending image is as follows...
Try this
// Server Side code for image sending
ServerSocket servsock = new ServerSocket(13250);
System.out.println("Main Waiting...");
Socket sock = servsock.accept();
System.out.println("Accepted connection : " + sock);
File myFile = new File ("\sdcard\ab.jpg");
byte [] mybytearray = new byte [(int)myFile.length()];
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(mybytearray,0,mybytearray.length);*/
byte [] mybytearray =new byte[count];
System.arraycopy(Copy, 0, mybytearray, 0, count);
OutputStream os = sock.getOutputStream();
System.out.println("Sending...");
os.write(mybytearray,0,mybytearray.length);
os.flush();
os.close();
sock.close();
servsock.close();
//Client side code for image reception
try
{
int filesize=6022386; // filesize temporary hardcoded
long start = System.currentTimeMillis();
int bytesRead;
int current = 0;
// localhost for testing
ServerSocket servsocket = new ServerSocket(13267);
System.out.println("Thread Waiting...");
Socket socket = servsocket.accept();
System.out.println("Accepted connection : " + socket);
System.out.println("Connecting...");
File f=new File("\sdcard\ab.jpg");
f.createNewFile();
// receive file
byte [] mybytearray = new byte [filesize];
InputStream is = socket.getInputStream();
FileOutputStream fos = new FileOutputStream(f);
BufferedOutputStream bos = new BufferedOutputStream(fos);
bytesRead = is.read(mybytearray,0,mybytearray.length);
current = bytesRead;
do {
bytesRead =
is.read(mybytearray, current, (mybytearray.length-current));
if(bytesRead >= 0) current += bytesRead;
} while(bytesRead > -1);
count=current;
Copy=mybytearray.clone();
bos.write(mybytearray, 0 , current);
bos.flush();
long end = System.currentTimeMillis();
System.out.println(end-start);
bos.close();
fos.close();
socket.close();
servsocket.close();
}
} catch(IOException e)
{
System.out.println("errorr");
}

Sending file from one client to another client using socket in java

Hello everyone ,
I am trying to develop the application for transfering/sending the file like SKYPE works.So I am using socket for transfering file from one computer(client) to another computer(client) .I am able to transfer file from one client to server using this. code.But when I try to send the same file from server to second client.It is transfering with 0 byte also give socket close exception so I try to create new socket object at client side.So Now the Exception not coming but file not transfering to client.After debugging I found that the file is successfully sent to client by server but at client side socket is not able to read the data and waiting for data.I can’t find any better solution.If anyone knows anything about this Please tell me.If you have any other solution for file transfer than also tell me.Thanks in advance
Below is my code
Server code:
public class ChatServer
{
serversocket = new ServerSocket(1436);
thread = new Thread(this);
thread.start();
/*************Thread Implementation***************/
public void run()
{
/*********Accepting all the client connections and create a seperate thread******/
while(thread != null)
{
try
{
/********Accepting the Server Connections***********/
socket = serversocket.accept();
/******* Create a Seperate Thread for that each client**************/
chatcommunication = new ChatCommunication(this,socket);
thread.sleep(THREAD_SLEEP_TIME);
}
catch(InterruptedException _INExc) { ExitServer(); }
catch(IOException _IOExc) { ExitServer(); }
}
}
protected void SendGroupFile(Socket ClientSocket, String FileName,String GroupName,String UserName) throws IOException
{
try
{
// receive file from Client
byte [] mybytearray = new byte [filesize];
InputStream is = socket.getInputStream();
FileOutputStream fos = new FileOutputStream(Filepath);
BufferedOutputStream bos = new BufferedOutputStream(fos);
int bytesRead = is.read(mybytearray,0,mybytearray.length);
current = bytesRead;
do {
bytesRead =is.read(mybytearray, current, (mybytearray.length-current));
System.out.println("Reading Bytes server"+bytesRead);
if(bytesRead >= 0)
current += bytesRead;
} while(bytesRead > -1);
bos.write(mybytearray,0,current);
bos.flush();
bos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/***** Function To Send a File to Client **********/
protected void SendGroupFileClient(Socket ClientSocket, String FileName,String GroupName,String UserName)
{
try {
int m_userListSize = userarraylist.size();
clientobject = GetClientObject(GroupName);
if(clientobject != null)
for(G_ILoop = 0; G_ILoop < m_userListSize; G_ILoop++)
{
clientobject = (ClientObject) userarraylist.get(G_ILoop);
if((clientobject.getGroupName().equals(GroupName)) && (!(clientobject.getUserName().equals(UserName))))
{
{
File myFile = new File (Filepath);
byte [] mybytearray = new byte [(int)myFile.length()];
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(mybytearray,0,mybytearray.length);
os = socket.getOutputStream();
System.out.println("Sending...");
os.write(mybytearray,0,mybytearray.length);
os.flush();
os.close();
}
}catch(IOException _IOExc)
{
_IOExc.printStackTrace();
}
}
}
ChatCommunication .java
public class ChatCommunication implements Runnable,CommonSettings
{
Thread thread;
Socket socket;
DataInputStream inputstream;
String RFC;
ChatServer Parent;
/********Initialize the Socket to the Client***********/
ChatCommunication(ChatServer chatserver,Socket clientsocket)
{
Parent = chatserver;
socket = clientsocket;
try
{
inputstream = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
}catch(IOException _IOExc) { }
thread = new Thread(this);
thread.start();
}
public void run()
{
while(thread != null)
{
try {
RFC = inputstream.readLine();
if(RFC.startsWith("FILEGRUP"))
{
Parent.SendGroupFile(socket,RFC.substring(9,RFC.indexOf("!")),RFC.substring(RFC.indexOf("!")+1,RFC.indexOf("*")),RFC.substring(RFC.indexOf("*")+1));
}
if(RFC.startsWith("FILEGET"))
{
Parent.SendGroupFileClient(socket,RFC.substring(8,RFC.indexOf("!")),RFC.substring(RFC.indexOf("!")+1,RFC.indexOf("*")),RFC.substring(RFC.indexOf("*")+1));
}
}catch(Exception _Exc)
{
Parent.RemoveUserWhenException(socket);QuitConnection();
}
}
}
Client code
class Client extends JFrame
{
ServerName="192.168.1.103";
ServerPort=1436;
Client()
{
socket = new Socket(ServerName,ServerPort);
SendGroupFileToServer(Filepath,SelectedGroup);
}
/*******Function To Send File To Server and receiving the file ***********/
protected void SendGroupFileToServer(String FileName, String ToGroup)
{
try {
dataoutputstream.writeBytes(FileName.concat("!").concat(ToUser)+"\r\n");
//send file to sever
File myFile = new File (FileName.substring(9));
byte [] mybytearray = new byte [(int)myFile.length()];
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(mybytearray,0,mybytearray.length);
OutputStream os = socket.getOutputStream();
System.out.println("Sending...");
os.write(mybytearray,0,mybytearray.length);
os.flush();
os.close();
System.out.println("File successfully Sended to server");
}catch(IOException _IoExc) { QuitConnection(QUIT_TYPE_DEFAULT);}
try {
socket1 = new Socket(ServerName,ServerPort); //Creating new Socket
dataoutputstream = new DataOutputStream(socket1.getOutputStream());
dataoutputstream.writeBytes("FILEGET"+FileName.concat("!").concat(ToGroup+"*"+UserName)+"\r\n"); //sending string to server
} catch (IOException e1) {
e1.printStackTrace();
}
// receive file sended by server
byte [] mybytearray = new byte [filesize];
InputStream is;
try {
is = socket1.getInputStream();
FileOutputStream fos = new FileOutputStream(Filepath);
BufferedOutputStream bos = new BufferedOutputStream(fos);
int bytesRead = is.read(mybytearray,0,mybytearray.length);
current = bytesRead; //up to this working fine
do {
bytesRead =is.read(mybytearray, current, (mybytearray.length-current)); //not reading the file data sent by server just waiting and not go ahead
if(bytesRead >= 0)
current += bytesRead;
} while(bytesRead > -1);
bos.write(mybytearray,0,current);
bos.flush();
bos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

There are so many problems here that it is difficult to know where to start.
The thread.sleep() in the accept() loop is literally a waste of time. It serves no useful purpose except possibly to throttle the rate at which clients are accepted. If that wasn't your intention, don't do it.
All you are doing when you catch an exception is exiting the server without even printing the exception message. So when something goes wrong, as it is here, you can't possibly know what it was. Don't do that.
readLine() returns null at EOS, on which you must close the socket, stop reading, and exit the thread. You aren't testing that, and you are therefore omitting all three of those required steps. Don't do that.
You are constructing a DataInputStream around a BufferedInputStream for use when reading commands, but you aren't passing it to the methods that process those commands. You are just passing the socket. You are therefore losing data. Don't do that. Every part of the program must use the same input stream or reader for the socket.
You are reading the entire file into memory. This (a) assumes the file size fits into an int; (b) does not scale to large files; (c) wastes space, and (d) adds latency. Don't do that.
You are ignoring the result of the read() into that buffer and assuming it was filled. You can't do that. The correct way to copy streams in Java is shown below. This works with a buffer of any size, e.g. 8192, for an input of any length, and doesn't require you to buffer the entire input into memory. You can use this loop at both the client when sending the file and at the server when receiving it.
while ((count = in.read(buffer)) > 0)
{
out.write(buffer, 0, count);
}
Similarly to (4) above, you are using a DataOutputStream around a BufferedOutputStream for some things and the socket output stream directly for others. Don't do that. All parts of the program must the same output stream or writer for the socket.
You don't need to flush() before close(); it happens automatically.
For some reason after sending the file you are creating a new connection and sending another command. You aren't even closing the connection afterwards. The server will have no easy way of knowing that this connection and this command referred to the file just sent in the code above. It is also redundant, as the receipt of the final EOS tells the server that the file has been sent successfully. Don't do this. If you need to send more information with the file, send it first, before the file, on the same connection.
The reference you cite exhibits many of the above issues. Make an effort to find a reputable starting point.

This is the solution. Please Apply this logic to your code.
I am able to send a file from server to client and client to server.
Check the following code to send the file from Client to Server. It is working great.
If you have any issues let me know.
Server Side Code:
public class ServerRecieveFile {
public static void main(String[] args) throws IOException {// TODO Auto-enerated method stub int filesize=1022386;
int bytesRead; int currentTot= ;
ServerSocket serverSocket=new ServerSocket(15123);
Socket socket=rverSocket.accept();
byte [] bytearray = new byte [filesize];
InputStream is=socket.getInputStream();
File copyFileName=new File("c:/Files Sockets/2.txt");
FileOutputStream fos = new FileOutputStream(copyFileName);
BufferedOutputStream bos = new BufferedOutputStream(fos);
bytesRead = is.read(bytearray,0,bytearray.length);
currentTot = bytesRead;
do {
bytesRead =is.read(bytearray, currentTot, (bytearray.length-currentTot)); if(bytesRead >= 0)
currentTot += bytesRead;
} while(bytesRead > -1);
bos.write(bytearray, 0 , currentTot);
bos.flush();
bos.close();
socket.close();
}
}
Client Side code:
public class ClientSendFile {
public static void main(String[] args) throws UnknownHostException, IOException {// TODO Auto-generated method stub
Client client=new Client();
Socket socket = new Socket(InetAddress.getLocalHost(),15123);
System.out.println("Accepted connection : " + socket);
File transferFile = new File ("c:/Files Sockets/1.txt");
byte [] bytearray = new byte (int)transferFile.length()];
FileInputStream fin = new FileInputStream(transferFile);
BufferedInputStream bin = new BufferedInputStream(fin);
bin.read(bytearray,0,bytearray.length);
OutputStream os = socket.getOutputStream();
System.out.println("Sending Files...");
os.write(bytearray,0,bytearray.length);
os.flush();
socket.close();
System.out.println("File transfer complete");
}
}

Java Android Sockets

I'm currently working on an Android app which sends an string and a file to a java server app running on remote computer. This java server app should find the index on the file and send back the value of this index (The file structure is: index value. Example: 1 blue) The file is properly sent and received on the remote machine and I have a method which finds the value of the received index on the file. But when I'm trying to send the found value back to the phone I get an exception (closed socket), but I'm not closing the socket or any buffer. I'm not sure if the socket which is closed is the mobile app socket or the java server app socket. I'm using the same socket I use to send to receive (which is the way to work on Android). Sending the answer back to the phone is what my project is missing and is what I need help in. Here is my code:
Client app (Android app):
private class HeavyRemProcessing extends AsyncTask<String, Void, String>
{
protected String doInBackground(String... urls)
{
begins = System.currentTimeMillis();
remoteExecution();
ends= System.currentTimeMillis();
procTime=ends-begins;
aux= Long.toString(procTime);
return aux;
} //doInBackground() ends
protected void onPostExecute(String time)
{
textView1.setText("Result: "+result+". Processing Time: "+time+" milisecs");
}// onPostExecute ends
} //HeavyRemProcessing ends
public void executor(View view)
{
key="74FWEJ48DX4ZX8LQ";
HeavyRemProcessing task = new HeavyRemProcessing();
task.execute(new String[] { "????" });
} //executor() ends
public void remoteExecution()
{
// I have fixed IP and port I just deleted
String ip; //SERVER IP
int port; // SERVER PORT
try
{
cliSock = new Socket(ip, port);
file= new File("/mnt/sdcard/download/Test.txt");
long length = file.length();
byte[] bytes = new byte[(int) length];
FileInputStream fis = new FileInputStream(file);
BufferedInputStream bis = new BufferedInputStream(fis);
BufferedOutputStream out = new BufferedOutputStream(cliSock.getOutputStream());
BufferedReader in = new BufferedReader(new InputStreamReader(cliSock.getInputStream()));
int count;
key=key+"\r\n";
out.write(key.getBytes());
while ((count = bis.read(bytes)) > 0)
{
out.write(bytes, 0, count);
} //It works perfectly until here
//// PROBABLY HERE IS THE PROBLEM:
out.flush();
out.close();
fis.close();
bis.close();
result= in.readLine(); //RECEIVE A STRING FROM THE REMOTE PC
}catch(IOException ioe)
{
// Toast.makeText(getApplicationContext(),ioe.toString() + ioe.getMessage(),Toast.LENGTH_SHORT).show();
}
}catch(Exception exp)
{
//Toast.makeText(getApplicationContext(),exp.toString() + exp.getMessage(),Toast.LENGTH_SHORT).show();
}
} //remoteExecution ends
Java Server App (Remote PC)
public void receivingFile()
{
System.out.println("Executing Heavy Processing Thread (Port 8888).");
try
{
serverSocket = new ServerSocket(8888);
InputStream is = null;
OutputStream os= null;
FileOutputStream fos = null;
BufferedOutputStream bos = null;
BufferedOutputStream boSock =null;
DataOutputStream dataOutputStream=null;
int bufferSize = 0;
try
{
socket = serverSocket.accept();
System.out.println("Heavy Processing Task Connection from ip: " + socket.getInetAddress());
} catch (Exception ex)
{
System.out.println("Can't accept client connection: "+ex);
}
try
{
is = socket.getInputStream();
dataOutputStream = new DataOutputStream(socket.getOutputStream());
bufferSize = socket.getReceiveBufferSize();
}
catch (IOException ex)
{
System.out.println("Can't get socket input stream. ");
}
try
{
fos = new FileOutputStream(path);
bos = new BufferedOutputStream(fos);
}
catch (FileNotFoundException ex)
{
System.out.println("File not found. ");
}
byte[] bytes = new byte[bufferSize];
int count;
System.out.println("Receiving Transfer File!.");
while ((count = is.read(bytes)) > 0)
{
bos.write(bytes, 0, count);
}
System.out.println("File Successfully Received!.");
fos.close();
bos.flush();
bos.close();
is.close();
result= obj.searchIndex();
System.out.println("Found: "+result); //This correctly print the found value
dataOutputStream.writeUTF(result);
dataOutputStream.flush();
dataOutputStream.close();
System.out.println("Data sent back to the Android Client. ");
} catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
} // receivingFile() ends
Please if someone can help me I will really appreciate it. I'm thinking is something probably related with the buffers and the socket. My java server app throws an exception: "Closed Socket"... Thanks for your time,
Alberto.

I think your problem is that you closing the outputstream before closing the inputstream. This is a bug in android. Normally in java closing outputstream only flushes the data and closing inputstream causes the connection to be closed. But in android closing the outputstream closes the connection. That is why you are getting closed socket exception,
Put the statements
out.flush();
out.close();
after
result=in.readLine();
or just avoid those statements(out.flush and out.close). I had also faced a similar problem. See my question