tomcatjavaee：在调用时运行一个方法。战争已经展开

Question

我编写了一个从SMTP服务器检索邮件的程序。我需要首先启动服务器，然后用户可以使用RESTAPI获取信息

我如何运行一个方法来启动SMTP服务器（端口25）一旦启动。战争是由Tomcat部署的

我试过这样的方法：

   @WebListener
public class InitializeListner implements ServletContextListener {

    @Override
    public final void contextInitialized(final ServletContextEvent sce) {
        SMTPServer smtp_server = SMTPServer.getInstance();
        smtp_server.start();

    }

但它不起作用并抛出：

GRAVE: Erreur lors de la configuration de la classe d'écoute de l'application (application listener) 

com.smtp.server.Initializer$InitializeListner
java.lang.InstantiationException: com.smtp.server.Initializer$InitializeListner
    at java.lang.Class.newInstance(Unknown Source)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:119)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4733)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5251)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:725)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1092)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1834)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoSuchMethodException: com.smtp.server.Initializer$InitializeListner.<init>()
    at java.lang.Class.getConstructor0(Unknown Source)
    ... 15 more

多谢各位

编辑：这是我的实际代码

public class SMTPServer extends Wiser
{
    private SMTPServer()
    {}

    private static SMTPServer SMTPServerInstance = null;

    public static synchronized SMTPServer getInstance()
    {           
        if (SMTPServerInstance == null)
        {   
            SMTPServerInstance = new SMTPServer();
            SMTPServerInstance.setPort(25);
            SMTPServerInstance.setHostname("localhost");
        }
        return SMTPServerInstance;
    }
}