brave.netty.http.TestHttpHandler.java Source code

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Here is the source code for brave.netty.http.TestHttpHandler.java

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/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package brave.netty.http;

import brave.http.HttpTracing;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.util.CharsetUtil;
import io.netty.util.internal.StringUtil;
import java.io.IOException;

import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_LENGTH;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
import static io.netty.handler.codec.http.HttpHeaders.Values;
import static io.netty.handler.codec.http.HttpHeaders.isKeepAlive;
import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
import static io.netty.handler.codec.http.HttpResponseStatus.EXPECTATION_FAILED;
import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND;
import static io.netty.handler.codec.http.HttpResponseStatus.OK;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;

class TestHttpHandler extends ChannelInboundHandlerAdapter {

    private FullHttpRequest httpRequest;
    private HttpTracing httpTracing;

    public TestHttpHandler(HttpTracing httpTracing) {
        this.httpTracing = httpTracing;
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.flush();
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        if (msg instanceof FullHttpRequest) {
            httpRequest = (FullHttpRequest) msg;
        }
        String uri = httpRequest.uri();
        String content = null;
        HttpResponseStatus status = OK;
        if (uri.startsWith("/foo")) {
            content = "bar";
        } else if (uri.startsWith("/child")) {
            httpTracing.tracing().tracer().nextSpan().name("child").start().finish();
            content = "happy";
        } else if (uri.startsWith("/exception")) {
            throw new IOException("exception");
        } else if (uri.startsWith("/async")) {
            content = "async";
        } else if (uri.startsWith("/badrequest")) {
            status = BAD_REQUEST;
        } else {//not found
            status = NOT_FOUND;
        }

        writeResponse(status, content, ctx);
    }

    private boolean writeResponse(HttpResponseStatus responseStatus, String content, ChannelHandlerContext ctx) {
        if (StringUtil.isNullOrEmpty(content)) {
            content = Unpooled.EMPTY_BUFFER.toString();
        }
        // Decide whether to close the connection or not.
        boolean keepAlive = isKeepAlive(httpRequest);

        if (responseStatus == null) {
            responseStatus = httpRequest.getDecoderResult().isSuccess() ? OK : BAD_REQUEST;
        }
        // Build the response object.
        FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, responseStatus,
                Unpooled.copiedBuffer(content, CharsetUtil.UTF_8));

        response.headers().set(CONTENT_TYPE, "text/plain; charset=UTF-8");

        if (keepAlive) {
            // Add 'Content-Length' header only for a keep-alive connection.
            response.headers().set(CONTENT_LENGTH, response.content().readableBytes());
            // Add keep alive header as per:
            // - http://www.w3.org/Protocols/HTTP/1.1/draft-ietf-http-v11-spec-01.html#Connection
            response.headers().set(CONNECTION, Values.KEEP_ALIVE);
        }

        // Write the response.
        ctx.write(response);

        return keepAlive;
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        ctx.fireExceptionCaught(cause);
        // Write the response.
        writeResponse(EXPECTATION_FAILED, null, ctx);
    }
}