RpcServer实现有问题 about nettyrpc HOT 4 CLOSED

@Override
public void afterPropertiesSet() throws Exception {
    if (bossGroup == null) {
        bossGroup = new NioEventLoopGroup();
        bossInitializer = true;
    }
    if (workerGroup == null) {
        workerGroup = new NioEventLoopGroup();
        workerInitializer = true;
    }
    // 略...
}

@Override
public void destroy() throws Exception {
    closeFuture.sync();
    if (bossInitializer) {
        bossGroup.shutdownGracefully();
    }
    if (workerInitializer) {
        workerGroup.shutdownGracefully();
    }
}