Polling Servlet不允许继续进行申请

Question

我有一个在tomcat服务器启动时调用的Servlet。

的web.xml

 <servlet>
        <servlet-name>PollingServlet</servlet-name>
        <servlet-class>com.bsli.servlet.PollingServlet</servlet-class>
         <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>PollingServlet</servlet-name>
        <url-pattern>/PollingServlet</url-pattern>
    </servlet-mapping>

PollingServlet.java

public class PollingServlet extends HttpServlet{

        private static final long serialVersionUID = 1L;

        Logger logger = Logger.getLogger(PollingServlet.class);


        public void init(){

            try {
                super.init();

                logger.debug("PollingServlet :: Initializing ...");         

                try {
                    CMConnectionPool.destroyPool();

                    CMBConnection connection1 = CMConnectionPool.getConnection();
                    logger.debug("CM Connection 1 achieved");

                    CMBConnection connection2 = CMConnectionPool.getConnection();
                    logger.debug("CM Connection 2 achieved");

                    CMBConnection connection3 = CMConnectionPool.getConnection();
                    logger.debug("CM Connection 3 achieved");

                    CMBConnection connection4 = CMConnectionPool.getConnection();
                    logger.debug("CM Connection 4 achieved");

                    CMBConnection connection5 = CMConnectionPool.getConnection();
                    logger.debug("CM Connection 5 achieved");


                    CMConnectionPool.freeConnection(connection1);               

                    CMConnectionPool.freeConnection(connection2);

                    CMConnectionPool.freeConnection(connection3);

                    CMConnectionPool.freeConnection(connection4);

                    CMConnectionPool.freeConnection(connection5);


                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }           

                Thread pollThread = new Thread(new PollingFolder());
                pollThread.start();

                logger.debug("PollingServlet thread Started ..");

            } catch (ServletException e) {
                e.printStackTrace();
            }

        }

    }

当我使用上面的类来创建如上所述的ConnectionPool时，应用程序不会继续进行。我在日志文件中获得了上述日志，但之后没有任何反应。 当我评论1行时，它正常工作。