main() — netty Function Reference

Architecture documentation for the main() function in DnsClient.java from the netty codebase.

Function java Buffer Telemetry calls 1

Entity Profile

Buffer→ Telemetry→ main() — netty Function Reference

Dependency Diagram

graph TD
  d80cfba1_e8be_0f12_c3f4_b9fa5d605fef["main()"]
  c3c638e5_9ebc_2b4f_b4ee_c21c8f26e50f["DnsClient"]
  d80cfba1_e8be_0f12_c3f4_b9fa5d605fef -->|defined in| c3c638e5_9ebc_2b4f_b4ee_c21c8f26e50f
  306eda2d_b52c_fcba_5c5b_08402e1d1f90["handleQueryResp()"]
  d80cfba1_e8be_0f12_c3f4_b9fa5d605fef -->|calls| 306eda2d_b52c_fcba_5c5b_08402e1d1f90
  style d80cfba1_e8be_0f12_c3f4_b9fa5d605fef fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

example/src/main/java/io/netty/example/dns/udp/DnsClient.java lines 69–107

    public static void main(String[] args) throws Exception {
        InetSocketAddress addr = new InetSocketAddress(DNS_SERVER_HOST, DNS_SERVER_PORT);
        EventLoopGroup group = new MultiThreadIoEventLoopGroup(NioIoHandler.newFactory());
        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
             .channel(NioDatagramChannel.class)
             .handler(new ChannelInitializer<DatagramChannel>() {
                 @Override
                 protected void initChannel(DatagramChannel ch) throws Exception {
                     ChannelPipeline p = ch.pipeline();
                     p.addLast(new DatagramDnsQueryEncoder())
                     .addLast(new DatagramDnsResponseDecoder())
                     .addLast(new SimpleChannelInboundHandler<DatagramDnsResponse>() {
                        @Override
                        protected void channelRead0(ChannelHandlerContext ctx, DatagramDnsResponse msg) {
                            try {
                                handleQueryResp(msg);
                            } finally {
                                ctx.close();
                            }
                        }
                    });
                 }
             });
            final Channel ch = b.bind(0).sync().channel();
            DnsQuery query = new DatagramDnsQuery(null, addr, 1).setRecord(
                    DnsSection.QUESTION,
                    new DefaultDnsQuestion(QUERY_DOMAIN, DnsRecordType.A));
            ch.writeAndFlush(query).sync();
            boolean succ = ch.closeFuture().await(10, TimeUnit.SECONDS);
            if (!succ) {
                System.err.println("dns query timeout!");
                ch.close().sync();
            }
        } finally {
            group.shutdownGracefully();
        }
    }