content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF 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 org.apache.beam.runners.dataflow.worker.status;
  
  import java.io.IOException;
  import java.util.function.BooleanSupplier;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  /** Respond to /healthz with health information. */
  public class HealthzServlet extends BaseStatusServlet {
  
    private final BooleanSupplier healthyIndicator;
  
    public HealthzServlet(BooleanSupplier healthyIndicator) {
      super("healthz");
      this.healthyIndicator = healthyIndicator;
    }
  
    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
      response.setContentType("text/html;charset=utf-8");
      if (healthyIndicator.getAsBoolean()) {
        response.setStatus(HttpServletResponse.SC_OK);
        response.getWriter().println("ok");
      } else {
        response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        response.getWriter().println("internal server error");
      }
    }
  }
  