B4J Question B4J UI App cann't run in debian/virtualbox

[jinyistudio]

My UI can run in Windows7 but it cann't run in debian 8.5/Virtualbox. I alwasy get following message

java version is "1.7.0_111"

Exception in thread "AWT-EventQueue-0"
java.awt.HeadlessException:
No X11 DISPLAY variable was set, but this program performed an operation which requires it.
    at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:207)
    at java.awt.Window.<init>(Window.java:535)
    at java.awt.Frame.<init>(Frame.java:420)
    at javax.swing.JFrame.<init>(JFrame.java:218)
    at com.javafx.main.Main$1.run(Main.java:882)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:312)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:745)
    at java.awt.EventQueue.access$300(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:706)
    at java.awt.EventQueue$3.run(EventQueue.java:704)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:715)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

#Region  Project Attributes
    #MainFormWidth: 800
    #MainFormHeight: 480
#End Region

Sub Process_Globals
    Private fx As JFX
    Private MainForm As Form
    Private we,temp As JavaObject  
    Private startPage As String = "http://127.0.0.1:8001"
    Private doc As JavaObject        ' JavaObject library
    Private js As jScriptEngine     ' jScriptEngine library
    Private WebView1 As WebView
End Sub

Sub AppStart (Form1 As Form, Args() As String)
    MainForm = Form1
    MainForm.SetFormStyle("UNIFIED")
    MainForm.rootPane.LoadLayout("main1") 'Load the layout file.
    temp = WebView1
    we = temp.RunMethod("getEngine",Null)
    WebView1.Enabled = True
    WebView1.Visible = True
    we.RunMethod("load",Array As Object(startPage))
    MainForm.Show
End Sub

Sub WebView1_PageFinished (Url As String)
  
End Sub

Sub WebView1_LocationChanged (Location As String)
  
End Sub

 

[Erel]

UI apps require Java 8+.

However based on the error message it seems like you are trying to run it from a non-graphic terminal. Check this answer: http://stackoverflow.com/questions/662421/no-x11-display-variable-what-does-it-mean