在单元测试中使用单例类获取ExceptionInInitializerError

Question

我有这样的单例课程

public class EventProcessor{
     //........

   private EventProcessor() {
     Client client = ClientBuilder.newClient();
     String scheme = requiredHttps() ? "https" : "http";
     m_webTarget = client.target(..........);
   }

   public static EventProcessor getAuditEventProcessor() {
        return m_EventProcessor.instance();
 }

   protected boolean requiredHttps() {
       // read value from config file
       // Configuration class is also a singleton and getConfig() is a static method
        Map map = Configuration.getConfig().getCurrent().getSecuritySettings().getSettings();  


      //...............
   }
}

在编写单元测试时，我有这样的设置方法

private EventProcessor m_EventProcessor;

 @Before
 public void setup() {
  MockitoAnnotations.initMocks(this);
  m_EventProcessor = EventProcessor.getAuditEventProcessor();      
 }

我为“ m_EventProcessor = EventProcessor.getAuditEventProcessor（）;”得到了ExceptionInInitializerError。有人可以帮我弄清楚这是什么问题吗？是因为在另一个单例类中调用一个单例类吗？