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Trouble with sending / receiving data

So I am attempting to send data to myself and receive the data then print it, now I have been testing for a while and I have noticed its not sending anything, in fact, maybe it is and I am not receiving it properly, I need assistance with this please.
This is what I am using to send data
String host = "127.0.0.1";
int port = Options.port;
Socket socket = new Socket(host, port);
OutputStream os = socket.getOutputStream();
OutputStreamWriter osw = new OutputStreamWriter(os);
BufferedWriter bw = new BufferedWriter(osw);
bw.write(msg + "\n");
bw.flush();
This is what I am using to receive, I always use this method and it never works so I would not be surprised if this was the root cause.
ServerSocket serverSocket = new ServerSocket(Options.port);
System.out.println("[Listening on port] " + Options.port);
while(true){
Socket socket = serverSocket.accept();
socket = serverSocket.accept();
InputStream is = socket.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String message = br.readLine();
System.out.println(message);
}

1) replace:
Socket socket = serverSocket.accept();
socket = serverSocket.accept();
with:
Socket socket = serverSocket.accept();
2) If this does not solve the problem, set ports as int values, without Options.port

Java Socket Client not Recieving Data

I have created my first test application implementing a socket server. I am having some issues getting the client to receive data, but the server gets data just fine. Here is the server:
ServerSocket socket = new ServerSocket(11111);
System.out.println("CREATING SERVER...");
while (true) {
Socket SERVER_WORK = socket.accept();
BufferedReader clientIN = new BufferedReader(new InputStreamReader(SERVER_WORK.getInputStream()));
PrintWriter outSend = new PrintWriter(SERVER_WORK.getOutputStream());
String ClientSTR = clientIN.readLine();
System.out.println("Client 1: " + ClientSTR);
String toClient = "Hello";
outSend.write(toClient + '\n');
}
And here is the client:
System.out.println("CONNECTING TO SERVER...");
while (true) {
Socket clientSocket = new Socket(server, 11111);
BufferedReader fromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
DataOutputStream toServere = new DataOutputStream(clientSocket.getOutputStream());
Scanner in = new Scanner(System.in);
toServere.write(in.nextLine().getBytes());
if (fromServer.ready())
System.out.println(fromServer.readLine());
clientSocket.close();
}
Everything works properly except for the client receiving data.

I found the solution: I needed a '\n' at the end of the line for the DataOutputStream/PrintWriter for the BufferedReader to work properly.

Send string to client upon command JAVA

So I am trying to have a sever sit and listen waiting for a connection from a client. The client sends over some string and the sever does some action based on whats received. Now what I would like to happen is the client sends over some command asking for data back and have the server get what it needs to and send the string back.
Not a big deal right? Well for some reason I can't get it working, my best guess is that its not closing the socket properly. I can't figure out why it wouldn't or what I am doing wrong.
Client
String data = "";
DataOutputStream outToServer = null;
BufferedReader input;
try {
outToServer = new DataOutputStream(clientSocket.getOutputStream());
outToServer.writeBytes("GETDATA");
outToServer.flush();
input = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
data = input.readLine();
Log.d("ANSWER: ", data);
input.close();
} catch (IOException e) {
Log.d("Error: ", e.toString());
}
Server
ServerSocket listeningSocket = new ServerSocket(9008);
BufferedReader fromClient ;
PrintStream os;
while(true) {
Socket clientSocket = listeningSocket.accept();
ServerConnection clientConnection = new ServerConnection(clientSocket);
os = new PrintStream(clientSocket.getOutputStream());
fromClient= new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
if(fromClient.readLine().equals("GETDATA")){
os.println("DATA");
os.flush();
clientSocket.wait();
clientSocket.close();
}
else{
clientConnection.run();
}
}
Any ideas?

here is your error
outToServer.writeBytes("GETDATA");
the right code is
outToServer.writeBytes("GETDATA\n");
as your using readline you should send a full line with line break

How can I read in data from a socket and write it to a file?

What I am trying to do is to read in data from a socket connection then write all of that to a file. My reader and all the related statements are below. Any ideas why it is not working? If you can see a more efficient way to do this that would also be useful.
(My full code does successfully connect to the socket)
EDIT: Added more of my code.
public static void main(String args[]) throws IOException
{
Date d = new Date();
int port = 5195;
String filename = "";
//set up the port the server will listen on
ServerSocketChannel ssc = ServerSocketChannel.open();
ssc.socket().bind(new InetSocketAddress(port));
while(true)
{
System.out.println("Waiting for connection");
SocketChannel sc = ssc.accept();
try
{
Socket skt = new Socket("localhost", port);
BufferedReader in = new BufferedReader(new InputStreamReader(skt.getInputStream()));
FileWriter logfile = new FileWriter(filename);
BufferedWriter out = new BufferedWriter(logfile);
BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
while ((inputLine = stdIn.readLine()) != null)
{
System.out.println("reading in data");
System.out.println(inputLine);
out.write(inputLine);
System.out.println("echo: " + in.readLine());
}
sc.close();
System.out.println("Connection closed");
}

You program requires you to type in a line for every line you read from the socket. Are you typing enough lines?
The lines you read from the console are written to the file, did you expect the lines from the socket to be written to the file?
Where are you closing the file (and the socket)
Another approach is to use a utility like Apache IOUtils
Socket skt = new Socket("localhost", port);
IOUtils.copy(skt.getInputStream(), new FileOutputStream(filename));
skt.close();

I think there's a typo in this line:
BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
Change "System.in" to just "in":
BufferedReader stdIn = new BufferedReader(new InputStreamReader(in));
FYI, here is how I like to read sockets. I prefer to avoid the string encoding offered by the readers, and just go straight for raw bytes:
byte[] buf = new byte[4096];
InputStream in = skt.getInputStream()
FileOutputStream out = new FileOutputStream(filename);
int c;
while ((c = in.read(buf)) >= 0) {
if (c > 0) { out.write(buf, 0, c); }
}
out.flush();
out.close();
in.close();
Oh, cute, turns out that code is essentially what IOUtils.copy() does (+1 to Peter Lawrey!):
http://svn.apache.org/viewvc/commons/proper/io/trunk/src/main/java/org/apache/commons/io/CopyUtils.java?view=markup#l193

how to implement TCP server and TCP client in java to transfer files

I have implement the simple TCP server and TCP client classes which can send the message from client to server and the message will be converted to upper case on the server side, but how can I achieve transfer files from server to client and upload files from client to server. the following codes are what I have got.
TCPClient.java:
import java.io.*;
import java.net.*;
class TCPClient {
public static void main(String args[]) throws Exception {
String sentence;
String modifiedSentence;
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
Socket clientSocket = new Socket("127.0.0.1", 6789);
DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
sentence = inFromUser.readLine();
outToServer.writeBytes(sentence + "\n");
modifiedSentence = inFromServer.readLine();
System.out.println("FROM SERVER:" + modifiedSentence);
clientSocket.close();
}
}
TCPServer.java:
import java.io.*;
import java.net.*;
class TCPServer {
public static void main(String args[]) throws Exception {
int firsttime = 1;
while (true) {
String clientSentence;
String capitalizedSentence="";
ServerSocket welcomeSocket = new ServerSocket(3248);
Socket connectionSocket = welcomeSocket.accept();
BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());
clientSentence = inFromClient.readLine();
//System.out.println(clientSentence);
if (clientSentence.equals("set")) {
outToClient.writeBytes("connection is ");
System.out.println("running here");
//welcomeSocket.close();
//outToClient.writeBytes(capitalizedSentence);
}
capitalizedSentence = clientSentence.toUpperCase() + "\n";
//if(!clientSentence.equals("quit"))
outToClient.writeBytes(capitalizedSentence+"enter the message or command: ");
System.out.println("passed");
//outToClient.writeBytes("enter the message or command: ");
welcomeSocket.close();
System.out.println("connection terminated");
}
}
}
So, the TCPServer.java will be executed first, and then execute the TCPClient.java, and I try to use the if clause in the TCPServer.java to test what is user's input,now I really want to implement how to transfer files from both side(download and upload).Thanks.

So lets assume on server side you have received the file name and file path. This code should give you some idea.
SERVER
PrintStream out = new PrintStream(socket.getOutputStream(), true);
FileInputStream requestedfile = new FileInputStream(completeFilePath);
byte[] buffer = new byte[1];
out.println("Content-Length: "+new File(completeFilePath).length()); // for the client to receive file
while((requestedfile.read(buffer)!=-1)){
out.write(buffer);
out.flush();
out.close();
}
requestedfile.close();
CLIENT
DataInputStream in = new DataInputStream(socket.getInputStream());
int size = Integer.parseInt(in.readLine().split(": ")[1]);
byte[] item = new byte[size];
for(int i = 0; i < size; i++)
item[i] = in.readByte();
FileOutputStream requestedfile = new FileOutputStream(new File(fileName));
BufferedOutputStream bos = new BufferedOutputStream(requestedfile);
bos.write(item);
bos.close();
fos.close();

Assuming you want to continue to support sending messages as well as sending files back and forth...
As you have now, you are using writeBytes to send data from client to server.
You can use that to send anything, like the contents of files...
But you will need to define a protocol between your client and server so that they know when a file is being transferred rather than a chat message.
For example you could send the message/string "FILECOMING" before sending a file to the server and it would then know to expecting the bytes for a file. Similarly you'd need a way to mark the end of a file too...
Alternatively, you could send a message type before each message.
A more performant/responsive solution is to do the file transfer on a separate thread/socket - this means that the chat messages are not held up by the transfers. Whenever a file transfer is required, a new thread/socket connection is created just for that.
~chris

import java.io.*;
import java.net.*;
class TCPClient
{
public static void main(String argv[]) throws IOException
{
String sentence;
String modifiedSentence;
Socket clientSocket = new Socket("*localhost*", *portnum*); // new Socket("192.168.1.100", 80);
System.out.println("Enter your ASCII code here");
BufferedReader inFromUser = new BufferedReader( new InputStreamReader(System.in));
sentence = inFromUser.readLine();
// System.out.println(sentence);
while(!(sentence.isEmpty()))
{
DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
outToServer.writeBytes(sentence);
BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
modifiedSentence = inFromServer.readLine();
while(!(modifiedSentence.isEmpty()))
{
System.out.println("FROM SERVER: " + modifiedSentence);
break;
}
System.out.println("Enter your ASCII code here");
inFromUser = new BufferedReader( new InputStreamReader(System.in));
sentence = inFromUser.readLine();
}
System.out.println("socket connection going to be close");
clientSocket.close();
}
}