content: /*
   * Copyright The OpenTelemetry Authors
   * SPDX-License-Identifier: Apache-2.0
   */
  
  package io.opentelemetry.smoketest.matrix;
  
  import jakarta.servlet.http.HttpServlet;
  import jakarta.servlet.http.HttpServletRequest;
  import jakarta.servlet.http.HttpServletResponse;
  import java.io.IOException;
  import java.io.PrintWriter;
  import java.util.Collections;
  import java.util.Enumeration;
  import java.util.List;
  
  public class HeaderDumpingServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
  
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
      PrintWriter response = resp.getWriter();
      Enumeration<String> headerNames = req.getHeaderNames();
      while (headerNames.hasMoreElements()) {
        String headerName = headerNames.nextElement();
        response.write(headerName + ": ");
  
        List<String> headers = Collections.list(req.getHeaders(headerName));
        if (headers.size() == 1) {
          response.write(headers.get(0));
        } else {
          response.write("[");
          for (String header : headers) {
            response.write("  " + header + ",\n");
          }
          response.write("]");
        }
        response.write("\n");
      }
  
      response.flush();
    }
  }
  