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 com.cloud.servlet;
  
  import java.util.Timer;
  import java.util.TimerTask;
  
  import javax.servlet.ServletConfig;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  
  import org.springframework.web.context.support.SpringBeanAutowiringSupport;
  
  import com.cloud.utils.LogUtils;
  import com.cloud.utils.SerialVersionUID;
  import com.cloud.utils.component.ComponentContext;
  import com.cloud.utils.db.TransactionLegacy;
  
  public class CloudStartupServlet extends HttpServlet {
      static final long serialVersionUID = SerialVersionUID.CloudStartupServlet;
  
      Timer _timer = new Timer();
  
      @Override
      public void init(ServletConfig config) throws ServletException {
          LogUtils.initLog4j("log4j-cloud.xml");
          SpringBeanAutowiringSupport.processInjectionBasedOnServletContext(this, config.getServletContext());
  
          // wait when condition is ready for initialization
          _timer.scheduleAtFixedRate(new TimerTask() {
              @Override
              public void run() {
                  if (ComponentContext.getApplicationContext() != null) {
                      _timer.cancel();
  
                      TransactionLegacy txn = TransactionLegacy.open(TransactionLegacy.CLOUD_DB);
                      try {
                          ComponentContext.initComponentsLifeCycle();
                      } finally {
                          txn.close();
                      }
                  }
              }
          }, 0, 1000);
      }
  }
  