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Create simple HTTP proxy server which replies fake contents, Java

I am trying to create a simple proxy server(very simple, doesn't even cache everything) that swaps contents(words, Images, and href) from the reply of origin and forward back to the client. (A proxy server that sends "Fake News" to the client).
I can change every occurrence of "Cat" into "Dog" and every occurrence of "Moon" to "Sun", but I don't know how to swaps the images and hrefs.
Thank you!
public class GetHttp {
public static String extractHost(String request) {
String[] tokens = request.split("\n");
String url = tokens[1].split(" ")[1];
return url;
}
public static byte[] replaceContext(byte[] message) {
String toReturn = new String(message);
// Here is the problem: I don't know how to swap href and images.
//toReturn = toReturn.replaceAll("<img src=\"This is a place holder\"","<img src=\"This is a place holder\" width");
//toReturn = toReturn.replaceAll("<a href=\"This is a place Holder\">", "<a href=\"This is a place Holder\">");
toReturn = toReturn.replaceAll("Cat", "Dog");
toReturn = toReturn.replaceAll("Moon", "Sun");
System.out.println(toReturn);
);
return toReturn.getBytes();
}
public static void main(String[] args) throws Exception {
ServerSocket server = new ServerSocket(8888);
while (true) {
Socket connectionSocket = server.accept();
BufferedInputStream inFromClient = new BufferedInputStream(connectionSocket.getInputStream());
// Server reads the HTTP request
byte[] buffer = new byte[8192];
inFromClient.read(buffer);
String clientRequest = new String(buffer);
String originName = extractHost(clientRequest);
// Create the http request from server to the origin
Socket origin = new Socket(InetAddress.getByName(originName.trim()), 80);
BufferedOutputStream outToOrigin = new BufferedOutputStream(origin.getOutputStream());
outToOrigin.write(clientRequest.getBytes());
outToOrigin.flush();
// receive the content from origin
// return back to the client
BufferedInputStream inFromOrigin = new BufferedInputStream(origin.getInputStream());
buffer = new byte[8192];
int buffersize = 0;
BufferedOutputStream outToClient = new BufferedOutputStream(connectionSocket.getOutputStream());
while ((buffersize=inFromOrigin.read(buffer)) != -1) {
byte[] temp = new byte[buffersize];
for(int i=0;i<buffersize;i++){
temp[i] = buffer[i];
}
// swap the context
outToClient.write(replaceContext(temp));// ,0,buffsize);
}
outToClient.flush();
outToOrigin.close();
inFromOrigin.close();
inFromClient.close();
outToClient.close();
origin.close();
connectionSocket.close();
}
}
}

Connect to MD110 pbx using c# Socket Programming

I am trying to login Ericsson MD110 alex through the c# application. The md110 returned values that asking the username for login the application, but once I pass the username and password through the following code:
public static void Main(string[] args)
{
try
{
byte[] data = new byte[1024];
string stringData;
//TcpClient tcpclnt = new TcpClient();
//Console.WriteLine("Connecting.....");
string ipaddress = "192.168.1.30";
int port=23;
IPAddress ipadd = IPAddress.Parse(ipaddress);
IPEndPoint ipend = new IPEndPoint(ipadd, port);
Socket sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
sock.NoDelay = false;
sock.Connect(ipend);
//recive data
int recv = sock.Receive(data);
stringData = Encoding.ASCII.GetString(data, 0, recv);
//textBox4.AppendText(stringData + "\r\n");
Console.Write(stringData);
//while (true)
//{
Byte[] bBuf;
string buf;
//Application.DoEvents();
//buf = String.Format("{0}\r\n{1}\r\n", "MDUSER", "HELP");
buf = String.Format("ALREI;");
//buf = string.Format("ENTER USER NAME<.MDUSER;MDUSER;ENTER PASSWORD<.HELP;");
bBuf = Encoding.ASCII.GetBytes(buf);
sock.Send(bBuf);
data = new byte[1024];
recv = sock.Receive(data);
stringData = Encoding.ASCII.GetString(data, 0, recv);
//textBox4.AppendText(stringData + "\r\n");
string df = "";
Console.Write(stringData);
Console.ReadLine();
//}
}
catch (Exception e)
{
Console.WriteLine("Error..... " + e.StackTrace);
Console.ReadKey();
}
}
Further, I checked with wireshark, but md110 doesn't return any value.
only acknowledge data packet will receive.
I need some advice.

exchange both string and binary data using socket without closing it

i'm working on an instant messaging project which it's client side is android and server is java
i need to use socket with streams
here is my protocol (something like HTTP) :
Method : attachment \n
Content-Length : {some-int-value} \n
\r\n
binary data bla bla bla...
lets assume i want to send this message from client to server
by doing so exchanging header section goes pretty well
but reading binary data at the server side never complete and server goes into hang for good
Client side code :
Socket socket = new Socket();
SocketAddress address = new InetSocketAddress(SERVER_ADDRESS, SERVER_PORT);
try {
socket.connect(address);
InputStream in = socket.getInputStream();
OutputStream out = socket.getOutputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in, "UTF-8"));
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(out, "UTF-8"));
byte[] data = getSomeBinaryData();
writer.write("Method : attachment" + "\n");
writer.write("Content-Length : " + data.length + "\n");
writer.write("\r\n");
writer.flush();
out.write(data); // write binary data
// do more exchange later
} catch (IOException ex) {
// handle exception
}
Server starter code :
public static void main(String[] args){
ExecutorService pool = Executors.newFixedThreadPool(50);
try (ServerSocket server = new ServerSocket(PORT_NUMBER)) {
while (true) {
try {
Socket connection = server.accept();
Callable<Void> task = new ClientTask(connection);
pool.submit(task);
} catch (IOException ex) {}
}
} catch (IOException ex) {
System.err.println("Couldn't start server");
}
}
Server Task thread for each client :
class ClientTask implements Callable<Void> {
private Socket connection;
private HashMap<String, String> header = new HashMap<>();
private byte[] content;
ClientTask(Socket c) {
this.connection = c;
}
#Override
public Void call() throws Exception {
InputStream in = connection.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in, "UTF-8"));
readHeader(reader);
System.out.println("incoming message : " + header.get("Method"));
int contentLength = Integer.parseInt(header.get("Content-Length"));
content = new byte[contentLength];
int bytesRead = in.read(content, 0, contentLength);
System.out.print(bytesRead);
return null;
}
private void readHeader(BufferedReader reader){
try {
char c;
StringBuilder builder = new StringBuilder();
while ((c = (char) reader.read()) != '\r'){
if(c == '\n'){
String line = builder.toString();
line = line.replaceAll(" ", "");
String[] sections = line.split(":");
header.put(sections[0], sections[1]);
builder = new StringBuilder(); // clear builder
}else {
builder.append(c);
}
}
reader.read(); // skip the last \n character after header
} catch (IOException e) {
e.printStackTrace();
}
}

As James said a clue I wanted to share the solution
maybe it help someone with similar issue
in the call method of ClientTask class i should use this code :
#Override
public Void call() throws Exception {
InputStream in = connection.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in, "UTF-8"));
readHeader(reader);
System.out.println("incoming message : " + header.get("Method"));
// read binary Content
int bytesRead = 0;
int bytesToRead = Integer.parseInt(header.get("Content-Length"));
content = new byte[bytesToRead];
while (bytesRead < bytesToRead) {
int result = in.read(content, bytesRead, bytesToRead - bytesRead);
if (result == -1)
break; // end of stream
bytesRead += result;
}
return null;
}

not able to send byte array from server to client,able to send from client to server

I have a task to do this.
Create a client and server socket interaction which accepts byte data and converts the byte data data received at server in the String and send back the response with the confirmation of the data conversation with success/unsuccess as the data passed will be with fix data length format so the validation should be done at server end.
As for e.g.
there are fields which ur sending to server like,
field 1 - number
field 2 - String
field 3 as Floating number i.e. 108.50
After conversion from byte to String :
152|any msg|108.50
In Byte it will be something like this,
10101|1001010010000000011000000000|1110111011
I have tried the following programs to do this
Server.java
public class Server extends Thread
{
private ServerSocket serverSocket;
public Server(int port) throws IOException
{
serverSocket = new ServerSocket(port);
//serverSocket.setSoTimeout(100000);
}
public void run()
{
while(true)
{
try
{
Socket server = serverSocket.accept();
byte Message[]=null;
DataInputStream in =
new DataInputStream(server.getInputStream());
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
int nRead;
byte[] data = new byte[16384];
while ((nRead = in.read(data, 0, data.length)) != -1) {
buffer.write(data, 0, nRead);
}
System.out.println("On this line"); //This doesnt get printed
buffer.flush();
data= buffer.toByteArray();
System.out.println(data);
String convertmsg = new String(data);
System.out.println("Msg converted "+convertmsg);
DataOutputStream out =
new DataOutputStream(server.getOutputStream());
System.out.println("below dataoutputstream");
out.write("Success".getBytes());
server.close();
}catch(SocketTimeoutException s)
{
System.out.println("Socket timed out!");
break;
}catch(IOException e)
{
e.printStackTrace();
break;
}
}
}
public static void main(String [] args)
{
int port = 4003;
try
{
Thread t = new Server(port);
t.start();
}catch(IOException e)
{
e.printStackTrace();
}
}
}
client
public class Client {
public static void main(String args[]) throws IOException
{
int userinput =1;
while(userinput==1)
{
String serverName = "192.168.0.8";
int port = 4003;
try
{
System.out.println("Connecting to " + serverName
+ " on port " + port);
Socket client = new Socket(serverName, port);
System.out.println("Just connected to "
+ client.getRemoteSocketAddress());
OutputStream outToServer = client.getOutputStream();
DataOutputStream out =
new DataOutputStream(outToServer);
System.out.println("above out.wirte()");
out.write("any msg".getBytes());
InputStream inFromServer = client.getInputStream();
DataInputStream in =
new DataInputStream(inFromServer);
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
int nRead;
System.out.println("converting array "+in);
byte[] data = IOUtils.toByteArray(in);
System.out.println(data);//This line doesnt get printed
//System.out.println("Server says " + in.readUTF());
client.close();
}catch(IOException e)
{
e.printStackTrace();
}
System.out.println("Enter userinput ");
DataInputStream dis = new DataInputStream(System.in);
String s = dis.readLine();
userinput = Integer.parseInt(s);
}
}
}
If i send data from client to server in bytes,it reads it and prints it.Also then the line "Enter userinput " gets printed and if the user enters '1' the program continues.
But the problem is this program given above. If i try to send data from server stating "success"(meaning the data has been converted from bytes to String successfully) then the program stucks and the cursor doesnt go below the line which are in comments "This line doesnt get printed".There is no error printed and none of the program terminates.I am new to socket programming and dont understand much about networking.
Any help will be truly appreciated.

You're reading the input until end of stream, but the peer isn't closing the connection, so end of stream never arrives.
I suggest you read and write lines, or use writeUTF() and readUTF().

Why do I get two connections from WebSocket client? One is "empty"

When I open a websocket connection to my websocket server application from Java, the server sees two connections. The first one never sends any data and the second one sends all the proper headers, etc. Anyone know what the reason for this is?
Client side connection is:
var websocket = new WebSocket( "ws://192.168.1.19:3333/websession" );
On the server side, in a while loop I call "serverSocket.accept()" and this gets called twice. But one of them never sends any data (the in.read() simply times out eventually without returning anything).
JAVA SERVER CODE
import java.net.*;
import java.io.*;
import java.security.*;
public class WebListener {
public static void main(String[] args) throws Exception {
ServerSocket serverSocket = null;
boolean listening = true;
try {
serverSocket = new ServerSocket(4444);
} catch (IOException e) {
System.err.println("Could not listen on port: 4444.");
System.exit(-1);
}
while (listening) new ServerThread(serverSocket.accept()).start();
serverSocket.close();
}
}
class ServerThread extends Thread {
private Socket socket = null;
public ServerThread(Socket socket) {
super("ServerThread");
this.socket = socket;
}
public void run() {
try {
OutputStream outStream = null;
PrintWriter out = new PrintWriter( outStream = socket.getOutputStream(), true);
BufferedReader in = new BufferedReader( new InputStreamReader( socket.getInputStream()));
String inputLine, outputLine;
//Handle the headers first
doHeaders( out, in );
// ..elided..
out.close();
in.close();
socket.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public void doHeaders(PrintWriter out, BufferedReader in) throws Exception {
String inputLine = null;
String key = null;
//Read the headers
while ( ( inputLine = in.readLine() ) != null ) {
//Get the key
if ( inputLine.startsWith( "Sec-WebSocket-Key" ) )
key = inputLine.substring( "Sec-WebSocket-Key: ".length() );
//They're done
if ( inputLine.equals( "" ) ) break;
}
//We need a key to continue
if ( key == null ) throw new Exception( "No Sec-WebSocket-Key was passed!" );
//Send our headers
out.println( "HTTP/1.1 101 Web Socket Protocol Handshake\r" );
out.println( "Upgrade: websocket\r" );
out.println( "Connection: Upgrade\r" );
out.println( "Sec-WebSocket-Accept: " + createOK( key ) + "\r" );
out.println( "\r" );
}
public String createOK(String key) throws NoSuchAlgorithmException, UnsupportedEncodingException, Exception {
String uid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
String text = key + uid;
MessageDigest md = MessageDigest.getInstance( "SHA-1" );
byte[] sha1hash = new byte[40];
md.update( text.getBytes("iso-8859-1"), 0, text.length());
sha1hash = md.digest();
return new String( base64( sha1hash ) );
}
public byte[] base64(byte[] bytes) throws Exception {
ByteArrayOutputStream out_bytes = new ByteArrayOutputStream();
OutputStream out = new Base64.OutputStream(out_bytes); //Using http://iharder.net/base64
out.write(bytes);
out.close();
return out_bytes.toByteArray();
}
private String convertToHex(byte[] data) {
StringBuffer buf = new StringBuffer();
for (int i = 0; i < data.length; i++) {
int halfbyte = (data[i] >>> 4) & 0x0F;
int two_halfs = 0;
do {
if ((0 <= halfbyte) && (halfbyte <= 9))
buf.append((char) ('0' + halfbyte));
else
buf.append((char) ('a' + (halfbyte - 10)));
halfbyte = data[i] & 0x0F;
} while(two_halfs++ < 1);
}
return buf.toString();
}
}

This looks to be a bug with Firefox. In Chrome it only opens one connection, while the same page in Firefox 15 opens two connections.