fixup dns lookup for multicast to use affinity thread.

filedatasink should mkdirs

Author: koush

AndroidAsync/src/com/koushikdutta/async/dns/Dns.java

@@ -61,6 +61,11 @@ public static Cancellable multicastLookup(String host, FutureCallback<DnsRespons
     }
 
     public static Future<DnsResponse> lookup(AsyncServer server, String host, final boolean multicast, final FutureCallback<DnsResponse> callback) {
+        if (!server.isAffinityThread()) {
+            SimpleFuture<DnsResponse> ret = new SimpleFuture<>();
+            server.post(() -> ret.setComplete(lookup(server, host, multicast, callback)));
+            return ret;
+        }
         ByteBuffer packet = ByteBufferList.obtain(1024).order(ByteOrder.BIG_ENDIAN);
         short id = (short)new Random().nextInt();
         short flags = (short)setQuery(0);

AndroidAsync/src/com/koushikdutta/async/stream/FileDataSink.java

@@ -21,6 +21,7 @@ public FileDataSink(AsyncServer server, File file) {
     public OutputStream getOutputStream() throws IOException {
         OutputStream ret = super.getOutputStream();
         if (ret == null) {
+            file.getParentFile().mkdirs();
             ret = new FileOutputStream(file);
             setOutputStream(ret);
         }