DataInputStream.readInt() is causing high latency, am I doing this wrong? - networking

Question

Under here you find a simple server/client app that sends the integer 5 from the client to the server, which reads it and sends it back to the client. On the server I have placed a latency meter around the DataInputStream.readInt() method, which reads that this method is causing a 400 ms latency.
Server code:
import java.io.*;
import java.net.*;
public class Server {
public static void main(String args[]) {
// declaration section:
ServerSocket echoServer = null;
Socket clientSocket = null;
int x;
// Try to open a server socket on port 4444
try {
echoServer = new ServerSocket(4444);
}
catch (IOException e) {
System.out.println(e);
}
//accept connection
try {
clientSocket = echoServer.accept();
//input
DataInputStream input = new DataInputStream(clientSocket.getInputStream());
//output
DataOutputStream output = new DataOutputStream(clientSocket.getOutputStream());
//loop
while(true){
long time = System.currentTimeMillis();
output.writeInt(input.readInt());
long dtime = System.currentTimeMillis();
System.out.println(dtime-time);
}
//close
// output.close();
// input.close();
// clientSocket.close();
// echoServer.close();
}catch (IOException e) {
System.out.println(e);
}
}
}
Client code:
import java.io.*;
import java.net.*;
public class Client {
public static void main(String[] args) {
// declaration section:
// clientClient: our client socket
// out: output stream
// in: input stream
Socket clientSocket = null;
// Initialization section:
// Try to open a socket on port 4444
// Try to open input and output streams
try{
clientSocket = new Socket("YOUR-IP-HERE", 4444);
//output
DataOutputStream output = new DataOutputStream(clientSocket.getOutputStream());
//input
DataInputStream input = new DataInputStream(clientSocket.getInputStream());
//loop
while(true) {
output.writeInt(5);
//System.out.println(input.readInt());
}
//close
// output.close();
// input.close();
// clientSocket.close();
}catch(Exception e) {
System.out.println("error");
}
}
}
Problem area:
//latencymeter
long time = System.currentTimeMillis();
//problem code
output.writeInt(input.readInt());
//latencymeter
long dtime = System.currentTimeMillis();
System.out.println(dtime-time);
Am I making a mistake in my code or am I not coding efficiently, please let me know.
Thanks

Answer 1

Solved: Adding clientSocket.setTcpNoDelay(true); on both server and client has brought the latency down to a normal 10-20 ms.