FULL PRODUCT VERSION :
java version "1.8.0_112"
Java(TM) SE Runtime Environment (build 1.8.0_112-b15)
Java HotSpot(TM) 64-Bit Server VM (build 25.112-b15, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 10.0.14393]

A DESCRIPTION OF THE PROBLEM :
URLConnection() doesn't handle unknown status codes in the informational range (100-199).

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run test code.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Infomational response should be consumed and skipped.

See "MUST" level requirement in <https://greenbytes.de/tech/webdav/rfc7231.html#rfc.section.6.2.p.2> (and the obsoleted spec: <https://greenbytes.de/tech/webdav/rfc2616.html#rfc.section.10.1.p.2>)
ACTUAL -
Informational message is treated as final response; consequently, the final message is returned as payload.


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.URL;

public class Test103 {

    public static void main(String[] args) throws IOException {
        Runnable server = new Runnable() {
            @Override
            public void run() {
                ServerSocket serverSocket = null;

                try {
                    serverSocket = new ServerSocket(8080);
                    String crlf = String.format("%c%c", 13, 10);
                    String payload = "Hello, world.";
                    byte[] message = ("HTTP/1.1 103 Hint" + crlf + "Link: </p>; rel=prefetch" + crlf + crlf
                            + "HTTP/1.1 200 OK" + crlf + "Content-Type: text/plain" + crlf + "Content-Length: " + payload.length()
                            + crlf + crlf + payload).getBytes();
                    // System.out.println(new String(message));
                    while (true) {
                        System.err.println("waiting");
                        Socket clientSocket = serverSocket.accept();
                        System.err.println("accepted");
                        clientSocket.getOutputStream().write(message);
                        clientSocket.close();
                    }
                } catch (IOException ex) {
                    ex.printStackTrace();
                } finally {
                    if (serverSocket != null) {
                        try {
                            serverSocket.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            };
        };
        Thread t = new Thread(server);
        t.start();
        java();
    }

    private static void java() throws IOException {
        URL test = new URL("http://localhost:8080");
        HttpURLConnection c = (HttpURLConnection) test.openConnection();
        System.out.println("Status: " + c.getResponseCode() + " "  + c.getResponseMessage());
        InputStream is = c.getInputStream();
        byte[] bytes = readFully(is);
        System.out.println("Body: " + new String(bytes));
    }

    public static byte[] readFully(InputStream is) throws IOException {
        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
        int nRead;
        byte[] data = new byte[16384];

        while ((nRead = is.read(data, 0, data.length)) != -1) {
            buffer.write(data, 0, nRead);
        }

        buffer.flush();

        return buffer.toByteArray();
    }
}

---------- END SOURCE ----------