Send HTTP request manually via socket

java http sockets network-programming http-headers
Eng.Fouad picture Eng.Fouad · May 20, 2012 · Viewed 92.7k times · Source

When I send a normal HTTP request via a socket, the server does not respond with an OK response. I copied the HTTP header from Firefox. Here is the code:

Socket s = new Socket(InetAddress.getByName("stackoverflow.com"), 80);
PrintWriter pw = new PrintWriter(s.getOutputStream());
pw.print("GET / HTTP/1.1");
pw.print("Host: stackoverflow.com");
pw.flush();
BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
String t;
while((t = br.readLine()) != null) System.out.println(t);
br.close();

However, here is the response I received:

HTTP/1.0 408 Request Time-out
Cache-Control: no-cache
Connection: close
Content-Type: text/html

<html><body><h1>408 Request Time-out</h1>
Your browser didn't send a complete request in time.
</body></html>

I know that I can do this by using URL.openStream(), but why doesn't the server identify the HTTP request when I send it manually?

Answer

Lycha picture Lycha · May 20, 2012

Two things:

  1. You should use println instead of print to print your entries to separate lines.
  2. HTTP request should end in a blank line (link). So add pw.println("");

Related questions

Does a TCP socket connection have a "keep alive"?

I have heard of HTTP keep-alive but for now I want to open a socket connection with a remote server. Now will this socket connection remain open forever or is there a timeout limit associated with it similar to HTTP …

Read More
How to prevent hangs on SocketInputStream.socketRead0 in Java?

Performing millions of HTTP requests with different Java libraries gives me threads hanged on: java.net.SocketInputStream.socketRead0() Which is native function. I tried to set up Apche Http Client and RequestConfig to have timeouts on (I hope) everythig that …

Read More
How to use java.net.URLConnection to fire and handle HTTP requests?

Use of java.net.URLConnection is asked about pretty often here, and the Oracle tutorial is too concise about it. That tutorial basically only shows how to fire a GET request and read the response. It doesn't explain anywhere how …

Read More