Interrupt exceptions should not lead to NPEs. Fixes #16.

Author: brainlag

src/main/java/com/github/brainlag/nsq/Connection.java

@@ -68,7 +68,9 @@ public Connection(final ServerAddress serverAddress, final NSQConfig config) thr
         final NSQCommand ident = NSQCommand.instance("IDENTIFY", config.toString().getBytes());
         try {
             final NSQFrame response = commandAndWait(ident);
-            LogManager.getLogger(this).info("Server identification: " + ((ResponseFrame) response).getMessage());
+            if (response != null) {
+                LogManager.getLogger(this).info("Server identification: " + ((ResponseFrame) response).getMessage());
+            }
         } catch (final TimeoutException e) {
             LogManager.getLogger(this).error("Creating connection timed out", e);
             close();

src/main/java/com/github/brainlag/nsq/NSQConsumer.java

@@ -153,7 +153,7 @@ private void cleanClose() {
         try {
             for (final Connection connection : connections.values()) {
                 final NSQFrame frame = connection.commandAndWait(command);
-                if (frame instanceof ErrorFrame) {
+                if (frame != null && frame instanceof ErrorFrame) {
                     final String err = ((ErrorFrame) frame).getErrorMessage();
                     if (err.startsWith("E_INVALID")) {
                         throw new IllegalStateException(err);

src/main/java/com/github/brainlag/nsq/NSQProducer.java

@@ -90,7 +90,7 @@ public void produceMulti(String topic, List<byte[]> messages) throws TimeoutExce
 
 
             NSQFrame frame = c.commandAndWait(command);
-            if (frame instanceof ErrorFrame) {
+            if (frame != null && frame instanceof ErrorFrame) {
                 String err = ((ErrorFrame) frame).getErrorMessage();
                 if (err.startsWith("E_BAD_TOPIC")) {
                     throw new BadTopicException(err);
@@ -112,7 +112,7 @@ public void produce(String topic, byte[] message) throws NSQException, TimeoutEx
         try {
             NSQCommand command = NSQCommand.instance("PUB " + topic, message);
             NSQFrame frame = c.commandAndWait(command);
-            if (frame instanceof ErrorFrame) {
+            if (frame != null && frame instanceof ErrorFrame) {
                 String err = ((ErrorFrame) frame).getErrorMessage();
                 if (err.startsWith("E_BAD_TOPIC")) {
                     throw new BadTopicException(err);