ADDITIONAL SYSTEM INFORMATION :
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.


C:\Program Files\Java\jdk1.8.0_212\bin>java -version
java version "1.8.0_212"
Java(TM) SE Runtime Environment (build 1.8.0_212-b10)
Java HotSpot(TM) 64-Bit Server VM (build 25.212-b10, mixed mode)

 

C:\Program Files\Java\jdk1.8.0_212\bin>javac -version
javac 1.8.0_212

A DESCRIPTION OF THE PROBLEM :
HttpUrlConnection.getResponseCode() hangs forever if Content-Length header is missing.
Server-Sent Events responses do not have "Content-Length" header. This causes HttpUrlConnection.getResponseCode() to hang if server response header and data come in one TCP packet.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Build and run test example code.

"C:\Program Files\Java\jdk1.8.0_212\bin\javac" -g -d out_test test.java

"C:\Program Files\Java\jdk1.8.0_212\bin\java" -cp out_test -agentlib:jdwp=transport=dt_shmem,address=jdbconn,server=y,suspend=n Test





EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The program exits normally.
ACTUAL -
The program hangs.

Backtrace is the following:
C:\Program Files\Java\jdk1.8.0_212\bin>jdb -attach jdbconn
Set uncaught java.lang.Throwable
Set deferred uncaught java.lang.Throwable
Initializing jdb ...
> suspend
All threads suspended.
> where all
Thread-0:
  [1] java.lang.Thread.sleep (native method)
  [2] Test$1.run (test.java:35)
Attach Listener:
Signal Dispatcher:
Finalizer:
  [1] java.lang.Object.wait (native method)
  [2] java.lang.ref.ReferenceQueue.remove (ReferenceQueue.java:144)
  [3] java.lang.ref.ReferenceQueue.remove (ReferenceQueue.java:165)
  [4] java.lang.ref.Finalizer$FinalizerThread.run (Finalizer.java:216)
Reference Handler:
  [1] java.lang.Object.wait (native method)
  [2] java.lang.Object.wait (Object.java:502)
  [3] java.lang.ref.Reference.tryHandlePending (Reference.java:191)
  [4] java.lang.ref.Reference$ReferenceHandler.run (Reference.java:153)
main:
  [1] java.net.SocketInputStream.socketRead0 (native method)
  [2] java.net.SocketInputStream.socketRead (SocketInputStream.java:116)
  [3] java.net.SocketInputStream.read (SocketInputStream.java:171)
  [4] java.net.SocketInputStream.read (SocketInputStream.java:141)
  [5] java.io.BufferedInputStream.fill (BufferedInputStream.java:246)
  [6] java.io.BufferedInputStream.read1 (BufferedInputStream.java:286)
  [7] java.io.BufferedInputStream.read (BufferedInputStream.java:345)
  [8] sun.net.www.http.HttpClient.parseHTTPHeader (HttpClient.java:735)
  [9] sun.net.www.http.HttpClient.parseHTTP (HttpClient.java:678)
  [10] sun.net.www.protocol.http.HttpURLConnection.getInputStream0 (HttpURLConnection.java:1 587)
  [11] sun.net.www.protocol.http.HttpURLConnection.getInputStream (HttpURLConnection.java:1 492)
  [12] java.net.HttpURLConnection.getResponseCode (HttpURLConnection.java:480)
  [13] Test.main (test.java:53)
>

---------- BEGIN SOURCE ----------
import java.io.*;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.net.*;

 

public class Test
{
    public static void main(String[] args) throws Exception
    {
        new Thread() {
        @Override public void run() {
            try {
               ServerSocket server = new ServerSocket(8087);
               Socket socket = server.accept();
               InputStream is = socket.getInputStream();
               byte h[] = new byte[200];
                is.read(h);
                   OutputStream os = socket.getOutputStream();

 

               String s = "HTTP/1.1 200 OK\n"+
               "Access-Control-Allow-Origin: *\n"+
               "Content-Type: text/event-stream\n"+
               "Cache-Control : no-cache\n"+
               "Connection : keep-alive\n"+
               "\n"+
               "data\n";
               byte[] arr = s.getBytes();

 

               os.write(arr);
    
                   System.out.println("Data sent\n");
               Thread.sleep(10000);

 

            } catch(Exception e) {
                System.out.println(e.toString());
            }
        }
        }.start();

 

        try{
            Thread.sleep(1000);
        }catch(Exception e){}

 

            URL url = new URL("http://127.0.0.1:8087/eventhub/events");
            HttpURLConnection c = (HttpURLConnection)url.openConnection();
            c.setRequestMethod("GET");
            c.setRequestProperty("Accept", "text/event-stream");
            c.connect();
            System.out.println("Resp code=" + c.getResponseCode());
            BufferedReader reader = new BufferedReader(new InputStreamReader(c.getInputStream()));
            String line = reader.readLine();
            System.out.println("Received: " + line);
            reader.close();
            c.disconnect();
        }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
There is no workaround.

FREQUENCY : always