Allow a map of request properties to be specified.

This adds an overload. A better way might be to configure some sort of builder
and finish with request(), but that's a larger refactor and if I was doing
that there'd be plenty to fix.

src/main/java/com/samskivert/net/HttpPostUtil.java

@@ -13,6 +13,9 @@ import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.URL;
 
+import java.util.Collections;
+import java.util.Map;
+
 import com.samskivert.util.ServiceWaiter;
 
 /**
@@ -28,7 +31,23 @@ public class HttpPostUtil
      * @param submission the entire submission eg "foo=bar&baz=boo&futz=foo".
      * @param timeout time to wait for the response, in seconds, or -1 for forever.
      */
-    public static String httpPost (final URL url, final String submission, int timeout)
+    public static String httpPost (URL url, String submission, int timeout)
+        throws IOException, ServiceWaiter.TimeoutException
+    {
+        return httpPost(url, submission, timeout, Collections.<String, String>emptyMap());
+    }
+
+    /**
+     * Return the results of a form post. Note that the http request takes place on another
+     * thread, but this thread blocks until the results are returned or it times out.
+     *
+     * @param url from which to make the request.
+     * @param submission the entire submission eg "foo=bar&baz=boo&futz=foo".
+     * @param timeout time to wait for the response, in seconds, or -1 for forever.
+     * @param requestProps additional request properties.
+     */
+    public static String httpPost (
+        final URL url, final String submission, int timeout, final Map<String, String> requestProps)
         throws IOException, ServiceWaiter.TimeoutException
     {
         final ServiceWaiter<String> waiter = new ServiceWaiter<String>(
@@ -41,6 +60,9 @@ public class HttpPostUtil
                     conn.setDoOutput(true);
                     conn.setUseCaches(false);
                     conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
+                    for (Map.Entry<String, String> entry : requestProps.entrySet()) {
+                        conn.setRequestProperty(entry.getKey(), entry.getValue());
+                    }
 
                     DataOutputStream out = new DataOutputStream(conn.getOutputStream());
                     out.writeBytes(submission);