FilterExampleServlet.java

package com.mycompany.servlet.filterlistener;

import io.honeycomb.beeline.DefaultBeeline;
import io.honeycomb.beeline.tracing.Span;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Example of how to use generated Beeline spans within the request itself.
 */
@SuppressWarnings("serial")
@WebServlet("/FilterExample")
public class FilterExampleServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // To add more spans or custom fields get the Beeline object from the request.
        // This was added by the Filter.
        DefaultBeeline beeline = (DefaultBeeline) req.getAttribute("beeline");

        // Add fields based on things like user input, SQL calls, or anything you can imagine.
        beeline.getActiveSpan().addField("fooParameter", req.getParameter("foo"));

        // More spans can be generated to time / gain insight into whatever you need.
        Span midSpan = beeline.startSpan("sleep");
        try {
            Thread.sleep(40);
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            midSpan.close();
        }

        Span sleepAgainSpan = beeline.startSpan("sleepAgain");
        try {
            Thread.sleep(30);
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            sleepAgainSpan.close();
        }

        // close HTTP writer
    }
}

HoneycombServletFilter.java

package com.mycompany.servlet.filterlistener;

import io.honeycomb.beeline.DefaultBeeline;
import io.honeycomb.beeline.tracing.Span;
import io.honeycomb.libhoney.shaded.org.apache.http.HttpHeaders;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebFilter("/*")
public class HoneycombServletFilter implements Filter {
    protected ServletContext servletContext;
    DefaultBeeline beeline;

    @Override
    public void init(FilterConfig filterConfig) {
        servletContext = filterConfig.getServletContext();
        beeline = DefaultBeeline.getInstance("yourname.jboss_servlet_filter", "FilterExampleService", "WRITEKEY");
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
            ServletException {
        final HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        final HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        final Span rootSpan = beeline.startSpan("ServletRequest");

        rootSpan.addField("request.content_length", request.getContentLength());
        rootSpan.addField("request.host", request.getServerName());
        rootSpan.addField("request.http_version", request.getProtocol());
        rootSpan.addField("request.method", httpServletRequest.getMethod());
        rootSpan.addField("request.path", httpServletRequest.getRequestURL().toString());
        rootSpan.addField("request.query", httpServletRequest.getQueryString());
        rootSpan.addField("request.header.accept", httpServletRequest.getHeader(HttpHeaders.ACCEPT));
        rootSpan.addField("request.header.user_agent", httpServletRequest.getHeader(HttpHeaders.USER_AGENT));

        try {
            request.setAttribute("beeline", beeline);
            chain.doFilter(request, response);
            rootSpan.addField("response.header_content_type", httpServletResponse.getHeader(HttpHeaders.CONTENT_TYPE));
            rootSpan.addField("response.status_code", httpServletResponse.getStatus());
        } finally {
            rootSpan.close();
            beeline.getBeeline().getTracer().endTrace();
        }
    }

    @Override
    public void destroy() {
        servletContext = null;
    }

}