What's the best way to reconnect after connection closed in Netty

Question

Simple scenario:

1. A lower level class A that extends SimpleChannelUpstreamHandler. This class is the workhorse to send the message and received the response.

Answer 1

Channel.closeFuture() returns a ChannelFuture that will notify you when the channel is closed. You can add a ChannelFutureListener to the future in B so that you can make another connection attempt there.

You probably want to repeat this until the connection attempt succeeds finally:

private void doConnect() {
    Bootstrap b = ...;
    b.connect().addListener((ChannelFuture f) -> {
        if (!f.isSuccess()) {
            long nextRetryDelay = nextRetryDelay(...);
            f.channel().eventLoop().schedule(nextRetryDelay, ..., () -> {
                doConnect();
            }); // or you can give up at some point by just doing nothing.
        }
    });
}