I am trying to send an HTML POST request over telnet in Java, I have some XML content which I have to send. But when I try to achieve in java, i am getting "Connection Reset" error. But the same when I do it over putty(unix), I am getting the response xml correctly.
Java Program I used : (Resulting in Connection Reset error)
public class Telnet {public static void main(String[] args) throws Exception {
Socket socket = new Socket("hostname", 10020);
String xmled = "<?xml version=1.0?><methodCall><methodName>GetVoucherDetails</methodName><params><param><value><struct><member><name>serialNumber</name><value><string>1038291567</string></value></member><member><name>networkOperatorId</name><value><string>vno2</string></value></member></struct></value></param></params></methodCall>";
System.out.println("Params: " + xmled);
try {
Writer out = new OutputStreamWriter(socket.getOutputStream(), "UTF-8");
out.write("POST /someContext HTTP/1.1\r\n");
out.write("Accept: text/xml\r\n");
out.write("Connection: close\r\n");
out.write("Content-Length: 489\r\n");
out.write("Content-Type: text/xml\r\n");
out.write("Host: ws2258:10010\r\n");
out.write("User-Agent: ADM/2.4/6.2\r\n");
out.write("Authorization: Basic cHBtc3VzZXI6dnNfJF9wcG11NWVy\r\n");
out.write(xmled);
out.write("\r\n");
out.flush();
InputStream inputstream = socket.getInputStream();
InputStreamReader inputstreamreader = new InputStreamReader(inputstream);
BufferedReader bufferedreader = new BufferedReader(inputstreamreader);
String string = null;
string = bufferedreader.readLine();
System.out.println(string);
while ((string = bufferedreader.readLine()) != null) {
System.out.println("Received " + string);
}
} catch(Exception e) {
e.printStackTrace();
} finally {
socket.close();
}
}
}
Please suggest me something, I am new to socket programming.
In your Socket constructor, did you mean to put port 10020? HTTP implies port 80 unless your web server is listening on port 10020.
I finally have found the solution for this problem. The fix was quiet simple at the end. We had to send the entire XML content in one single line rather then putting into multiple lines.
Related
This is part of the program that is having trouble.
public void run() {
while(!isStopped) {
try {
socket = server.accept();
System.out.println(socket.getRemoteSocketAddress() + " has connected");
//problem starts
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String request;
while((request = in.readLine()) != null) {
System.out.println(request);
} //problem ends
FileReader f = new FileReader("html/index.html");
BufferedReader br = new BufferedReader(f);
String response;
BufferedWriter out = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
out.write("HTTP/1.1 200 OK\r\n");
out.write("Content-type: text/html\r\n");
out.write("\r\n");
while((response = br.readLine()) != null) {
out.write(response);
}
out.close();
socket.close();
} catch(Exception e) {
System.out.println(e);
e.printStackTrace();
}
}
I created a java web server and it works fine with all the connections. But when the program listens to the request from client and print that request on the console, the program doesn't continue and so it doesn't respond with the HTML file. I tried getting rid of the printing the request part and the program easily sends the HTML but I don't like that because it doesn't print the initial request. How can I make the server properly listen and print client requests and send responses back accordingly and continue like this in a loop? It would be great to show the codes.
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);
}
}
}
}
}
}
I'm connecting to a remote TCP Listener that receives a string, and responds with a response.
Going from my Windows 8 Phone App, to a Java Jar. The Jar IS receiving the message, but the Windows 8 Phone App is not getting the response.
C# Code
outputClient.Connect (/IP ADDRESS/, /Port/);
using (Socket sock = outputClient.Client) {
sock.Send (UTF8Encoding.ASCII.GetBytes (broadcastMessage));
var response = new byte[100];
sock.Receive (response);
var str = Encoding.ASCII.GetString (response).Replace ("\0", "");
Console.WriteLine ("[RECV] {0}", str);
} <-- JAVA CODE DOESN'T GET HIT UNTIL THIS LINE IS COMPLETED
Java Code
String clientSentence;
ServerSocket socketServer = new ServerSocket(/* PORT */);
while (true)
{
Socket connectionSocket = socketServer.accept();
connectionSocket.setKeepAlive(true);
BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
clientSentence = inFromClient.readLine();
BufferedWriter outToClient = new BufferedWriter(new OutputStreamWriter(connectionSocket.getOutputStream()));
if (clientSentence != null)
{
try
{
JsonObject json = new JsonParser().parse(clientSentence).getAsJsonObject();
String un = json.get("Username").toString();
String uuid = "2c9c79a096ef4d869fb1d1e07469bb41".replaceAll(
"(\\w{8})(\\w{4})(\\w{4})(\\w{4})(\\w{12})",
"$1-$2-$3-$4-$5");
var val = /* Get val */
String response = gson.toJson(val);
outToClient.write(response);
outToClient.newLine();
outToClient.flush();
}
catch (Exception ex)
{
ex.printStackTrace();
outToClient.write(response);
outToClient.newLine();
outToClient.flush();
}
}
connectionSocket.close();
}
A little more explanation: JAVA CODE DOESN'T GET HIT UNTIL THIS LINE IS COMPLETED means that the socket appears to not be sending until using (Socket sock = outputClient.Client) is no longer being used.
I fixed it by replacing the C# code with:
using (TcpClient client = new TcpClient (/IP ADDRESS/, /PORT/))
using (NetworkStream stream = client.GetStream ())
using (StreamReader reader = new StreamReader (stream))
using (StreamWriter writer = new StreamWriter (stream)) {
writer.AutoFlush = true;
foreach (string lineToSend in linesToSend) {
Console.WriteLine ("Sending to server: {0}", lineToSend);
writer.WriteLine (lineToSend);
string lineWeRead = reader.ReadLine ();
Console.WriteLine ("Received from server: {0}", lineWeRead);
Thread.Sleep (2000); // just for effect
}
Console.WriteLine ("Client is disconnecting from server");
}
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.
I'm building a Java client application which needs to send a message to a server and receive a response afterwards. I can send the message successfully, the problem is that I can't get the response because I get an IO exception ("Socked is closed") when trying to read the 'BufferedReader'.
This is my code, so far:
public class MyClass {
/**
* #param args the command line arguments
*/
#SuppressWarnings("empty-statement")
public static void main(String[] args) {
JSONObject j = new JSONObject();
try {
j.put("comando", 1);
j.put("versao", 1);
j.put("senha", "c4ca4238a0b923820dcc509a6f75849b");
j.put("usuario", "1");
j.put("deviceId", "1");
} catch (JSONException ex) {
System.out.println("JSON Exception reached");
}
String LoginString = "{comando':1,'versao':1,'senha':'c4ca4238a0b923820dcc509a6f75849b','usuario':'1','deviceId':'1'}";
try {
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
Socket clientSocket = new Socket("10.1.1.12", 3333);
System.out.println("Connected to the server successfully");
PrintWriter outToServer = new PrintWriter(clientSocket.getOutputStream(),true);
outToServer.println(j.toString());
outToServer.close();
System.out.println("TO SERVER: " + j.toString());
BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
String resposta = inFromServer.readLine();
System.out.println("FROM SERVER: " + resposta);
clientSocket.close();
} catch (UnknownHostException ex) {
System.out.println("Could not connect to the server [Unknown exception]");
} catch (IOException ex) {
System.out.println(ex.getMessage());
}
}
}
I know that the socket is being closed because of the OutToServer.close() but closing the stream is the only way to send the message. How should I approach this situation?
flush() is not the case when it comes with new PrintWriter(, true).
The real problem is that you are closing the PrintWriter outToServer which wraps the underlying InputStream, again, came from the Socket.
When you close the outToServer you're closing the whole socket.
You have to use Socket#shutdownOutput().
You don't even have to close the output if you want to keep the socket's in/out channels for further communications.
flush() when you are done with any writeXXX. Those writeXXX practically don't mean you sent those bytes and characters to other side of the socket.
You may have to close the output, and output only, to signal the server that you sent all you had to send. This is really a matter of the server-side socket's desire.
final Socket socket = new Socket(...);
try {
final PrintStream out = new PrintStream(socket.getOutputStream());
// write here
out.flush(); // this is important.
socket.shutdownOutput(); // half closing
// socket is still alive
// read input here
} finally {
socket.close();
}
Try to call outToServer.flush()
That will try to flush the data from the buffer, although it still not guarantees that it will be sent.