com.yoho.core.trace.instrument.web.client.AbstractTraceHttpRequestInterceptor.java Source code

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Here is the source code for com.yoho.core.trace.instrument.web.client.AbstractTraceHttpRequestInterceptor.java

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/*
 * Copyright 2013-2016 the original author or authors.
 *
 * Licensed 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 com.yoho.core.trace.instrument.web.client;

import java.net.URI;

import com.yoho.core.trace.Span;
import com.yoho.core.trace.SpanInjector;
import com.yoho.core.trace.Tracer;
import org.springframework.http.HttpRequest;

/**
 * Abstraction over classes that interact with Http requests. Allows you
 * to enrich the request headers with trace related information.
 *
 * @author Marcin Grzejszczak
 *
 * @since 1.0.0
 */
public abstract class AbstractTraceHttpRequestInterceptor {

    protected final Tracer tracer;
    protected final SpanInjector<HttpRequest> spanInjector;

    protected AbstractTraceHttpRequestInterceptor(Tracer tracer, SpanInjector<HttpRequest> spanInjector) {
        this.tracer = tracer;
        this.spanInjector = spanInjector;
    }

    /**
     * Enriches the request with proper headers and publishes
     * the client sent event
     */
    protected void publishStartEvent(HttpRequest request) {
        URI uri = request.getURI();
        String spanName = uriScheme(uri) + ":" + uri.getPath();
        Span newSpan = this.tracer.createSpan(spanName);
        this.spanInjector.inject(newSpan, request);
        newSpan.logEvent(Span.CLIENT_SEND);
    }

    private String uriScheme(URI uri) {
        return uri.getScheme() == null ? "http" : uri.getScheme();
    }

    /**
     * Close the current span and log the client received event
     */
    public void finish() {
        if (!isTracing()) {
            return;
        }
        currentSpan().logEvent(Span.CLIENT_RECV);
        this.tracer.close(this.currentSpan());
    }

    protected Span currentSpan() {
        return this.tracer.getCurrentSpan();
    }

    protected boolean isTracing() {
        return this.tracer.isTracing();
    }

}