HttpClientHandler Class — netty Architecture

Source Code

example/src/main/java/io/netty/example/ocsp/OcspClientExample.java lines 156–205

    private static class HttpClientHandler extends ChannelInboundHandlerAdapter {

        private final String host;

        private final Promise<FullHttpResponse> promise;

        HttpClientHandler(String host, Promise<FullHttpResponse> promise) {
            this.host = host;
            this.promise = promise;
        }

        @Override
        public void channelActive(ChannelHandlerContext ctx) throws Exception {
            FullHttpRequest request = new DefaultFullHttpRequest(
                    HttpVersion.HTTP_1_1, HttpMethod.GET, "/", Unpooled.EMPTY_BUFFER);
            request.headers().set(HttpHeaderNames.HOST, host);
            request.headers().set(HttpHeaderNames.USER_AGENT, "netty-ocsp-example/1.0");

            ctx.writeAndFlush(request).addListener(ChannelFutureListener.FIRE_EXCEPTION_ON_FAILURE);

            ctx.fireChannelActive();
        }

        @Override
        public void channelInactive(ChannelHandlerContext ctx) throws Exception {
            if (!promise.isDone()) {
                promise.tryFailure(new IllegalStateException("Connection closed and Promise was not done."));
            }
            ctx.fireChannelInactive();
        }

        @Override
        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
            if (msg instanceof FullHttpResponse) {
                if (!promise.trySuccess((FullHttpResponse) msg)) {
                    ReferenceCountUtil.release(msg);
                }
                return;
            }

            ctx.fireChannelRead(msg);
        }

        @Override
        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
            if (!promise.tryFailure(cause)) {
                ctx.fireExceptionCaught(cause);
            }
        }
    }