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the buffer in server doesn't read the value that client sent

The client sends data (string) to the server, and the server must read it, but in my case the server didn't read the data (value) that the client sent, and I didn't know where is the problem exactly, because normally the steps to read data are all correct in the server side
Client side:
Socket socket = new Socket(address, authenticationServerPort);
username = username + "\n"; // to send username through socket without
String h=getUserInput();
// waiting
// Send the message to the server
// send public key
OutputStream os = socket.getOutputStream();
OutputStreamWriter osw = new OutputStreamWriter(os);
BufferedWriter bw = new BufferedWriter(osw);
System.out.println(h);
bw.write(h);
bw.flush();
System.out.println("Message sent to the Authentication server : "+ h);
Server side:
Socket clientSocket = null;
try {
System.out.println("Server Running");
int serverPort = 8029; // the server port we are using
ServerSocket listenSocket = new ServerSocket(serverPort);
List<BlockChain> resultList = new ArrayList<BlockChain>();
while (true) {
clientSocket = listenSocket.accept();
InputStream is = clientSocket.getInputStream();
System.out.println(is);
InputStreamReader isr = new InputStreamReader(is);
System.out.println(isr);
BufferedReader br = new BufferedReader(isr);
String request = br.readLine();
System.out.println("the msg receving from client is : "+request);
PrintWriter out;
out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream())));
if (clientSocket != null) {
clientSocket.close();
}
}
catch (Exception e) {
e.printStackTrace();// TODO: handle exception
}
}
Someone tell me where is the problem exactly.

Java Client C# Server sending issue

I am trying to set up Client-Server communication where C# is the
server side and Java is the client side. The connection is successful
and I am able to send a string from C# to Java. However, I am having
issues sending a string from Java to C#. The Server does not get any
input.
My code is the following: Server Side C#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.IO;
namespace ServerToJava
{
class Program
{
static void Main(string[] args)
{
TcpListener serverSocket = new TcpListener(5678);
int requestCount = 0;
TcpClient clientSocket = default(TcpClient);
serverSocket.Start();
Console.WriteLine(" >> Server Started");
clientSocket = serverSocket.AcceptTcpClient();
Console.WriteLine(" >> Accept connection from client");
requestCount = 0;
NetworkStream networkStream = clientSocket.GetStream();
try
{
requestCount = requestCount + 1;
string serverResponse = "Last Message from client server This is a test";
Byte[] sendBytes = Encoding.ASCII.GetBytes(serverResponse);
networkStream.Write(sendBytes, 0, sendBytes.Length);
Console.Write ("ReadClient Thread started");
int length = networkStream.ReadByte ();
byte[] buffer = new byte[length];
int size = networkStream.ReadByte ();
byte[] buff = new byte[size];
using (var memoryStream = new MemoryStream(buff,false)) {
using (var streamReader = new StreamReader(memoryStream, Encoding.UTF8)) {
var message = streamReader.ReadLine();
buff = Encoding.UTF8.GetBytes(message);
networkStream.Read(buffer, 0 ,buffer.Length);
Console.Write (message);
networkStream.Flush();
}
}
}
catch (Exception ex)
{
}
clientSocket.Close();
serverSocket.Stop();
Console.WriteLine(" >> exit");
Console.ReadLine();
}
}
}
Client Side Java
OutputStream out;
Socket s = new Socket("127.0.0.1", 5678);
BufferedReader input =
new BufferedReader(new InputStreamReader(s.getInputStream()));
String answer = input.readLine();
JOptionPane.showMessageDialog(null, answer);
out= s.getOutputStream();
out.write('a');
System.exit(0);

You shouldn't use new TcpListener(5678) it is Obsolete, instead use the following:
// Set the TcpListener on port 5678.
Int32 port = 5678;
IPAddress localAddr = IPAddress.Parse("127.0.0.1");
TcpListener server = new TcpListener(localAddr, port);
Source` MSDN

How to use BufferedReader to read content in DataInputStream

I wrote a simple socket tutorial about sending/receive messages between client and server. I used DataOutputStream to write the string in stream but server couldn't read it if I used BufferedReader
If I use PrintWriter to write(client side), it works.
What's wrong here? Tks so much.
1. Client:
client = new Socket("localhost", 1982);
DataOutputStream opStr = new DataOutputStream(client.getOutputStream());
//pw = new PrintWriter(client.getOutputStream(), true);
//pw.println("Hello, is there anybody out there?");// Can be read by BufferedReader
opStr.writeUTF("Hello, anyone there?");
opStr.flush();// BufferedReader can't read it
2. Server:
openServer();// port 1982
while(true) {
Socket clientSocket = null;
// listen to connection.
clientSocket = echoServer.accept();
DataInputStream inStr = new DataInputStream(
clientSocket.getInputStream());
//System.out.println("M1: Got msg " + inStr.readUTF());// It showed the content
BufferedReader bfReader = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
System.out.println("got Messages: ");
String strLine = "";
// Don't show anything
while ((strLine = bfReader.readLine()) != null) {
System.out.println(strLine);
}
}

You can't. If you use writeUTF() at one end, you have to use readUTF() at the other end.
You just have to decide which API you're going to use, instead of trying to mix and match them.

You want to read the files as either text e.g. BufferedReader OR binary e.g. DataInputStream. So you can't use both.
Server.java
public class Server
{
public static void main(String[] args)
{
DataInputStream inStr = null;
String str;
openServer();// port 1982
while(true)
{
Socket clientSocket = null;
// listen to connection.
clientSocket = echoServer.accept();
try
{
inStr = new DataInputStream(clientSocket.getInputStream());
str = inStr.readUTF();
System.out.print((String) str);
System.out.flush();
}
catch (IOException io)
{
System.err.println("I/O error occurred: " + io);
}
catch (Throwable anything)
{
System.err.println("Exception caught !: " + anything);
}
finally
{
if (inStr != null)
{
try
{
inStr.close();
}
catch (IOException io)
{
System.err.println("I/O error occurred: " + io);
}
}
}
}
}
}

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

Reading Http Get request from a inputstream and sending it to the host. using sockets

i have this assignment where i am supposed to write a proxy server that uses java sockets to handle get requests from a client. I am now stuck and have been looking all over google to find the answer but without success.
Christoffers solution helped my with my first problem. Now that i have updated the code this is what i am using.
The problem is that it only downloads parts of most webpages before it gets stuck on sending the packets back to the client loop. At the moment I cant explain why it is behaving the way it is.
public class MyProxyServer {
//Set the portnumber to open socket on
public static final int portNumber = 5555;
public static void main(String[] args){
//create and start the proxy
MyProxyServer myProxyServer = new MyProxyServer();
myProxyServer.start();
}
public void start(){
System.out.println("Starting MyProxyServer ...");
try {
//create the socket
ServerSocket serverSocket = new ServerSocket(MyProxyServer.portNumber);
while(true)
{
//wait for a client to connect
Socket clientSocket = serverSocket.accept();
//create a reader to read the instream
BufferedReader inreader = new BufferedReader( new InputStreamReader(clientSocket.getInputStream(), "ISO-8859-1"));
//string builder for preformance when we loop over the inputstream and read lines
StringBuilder builder = new StringBuilder();
String host = "";
for (String buffer; (buffer = inreader.readLine()) != null;) {
if (buffer.isEmpty()) break;
builder.append(buffer.replaceAll("keep-alive", "close"));
if(buffer.contains("Host"))
{
//parse the host
host = buffer.replaceAll("Host: ", "");
}
System.out.println(buffer);
}
String req = builder.toString();
System.out.println("finshed reading \n" + req);
System.out.println("host: " + host);
//new socket to send the information over
Socket s = new Socket(InetAddress.getByName(host), 80);
//printwriter to send text over the output stream
PrintWriter pw = new PrintWriter(s.getOutputStream());
//send the request from the client
pw.println(req+"\r\n");
pw.flush();
//create inputstream to receive the web page from the host
BufferedInputStream in = new BufferedInputStream(s.getInputStream());
//create outputstream to send the web page to the client
BufferedOutputStream outbuffer = new BufferedOutputStream(clientSocket.getOutputStream());
byte[] bytebuffer = new byte[1024];
int bytesread;
//send the response back to the client
while((bytesread = in.read(bytebuffer)) != -1) {
System.out.println(bytesread);
outbuffer.write(bytebuffer,0, bytesread);
outbuffer.flush();
}
System.out.println("done sending");
//close the streams
inreader.close();
s.close();
pw.close();
outbuffer.close();
in.close();
}
} catch (IOException e) {
e.printStackTrace();
} catch(RuntimeException e){
e.printStackTrace();
}
}
}
If anyone could explain to me why i cant get it working correctly and how to solve it I would be very grateful!
Thanks in advance.