Windows启动uiautomatorviewer，报错Exception in thread "main" java.lang.NullPointerException

具体位置报错如下:
Exception in thread "main" java.lang.NullPointerException
at com.android.ddmlib.MonitorThread.wakeup(MonitorThread.java:580)
at com.android.ddmlib.MonitorThread.quit(MonitorThread.java:588)
at com.android.ddmlib.AndroidDebugBridge.terminate(AndroidDebugBridge.java:235)
at com.android.uiautomator.DebugBridge.terminate(DebugBridge.java:78)
at com.android.uiautomator.UiAutomatorViewer.main(UiAutomatorViewer.java:85)

就只给个报错信息，恐怕只有神才能答得上来