B4J Code Snippet Additional jServer (web server) Setting Snippets

Just thought it would be good to keep additional jServer/Jetty/Web Server settings in one place.

I'll go first;

Set Max Post/Form Size (setMaxFormContentSize) (link)

Dim jo As JavaObject = webserver  
jo.GetFieldJO("context").RunMethod("setMaxFormContentSize", Array(10000000)) 'Size is in bytes, this example is 10mb

 

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Set Specific Host IP (to listen on?) (link)

Dim jo As JavaObject = webserver
jo.SetField("host", "ip.address")

 

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Set SetCookieJsessionidHttpOnly (setHttpOnly) (link)

Dim jo As JavaObject = webserver
Dim sessionmanager As JavaObject = jo.GetFieldJO("context").RunMethodJO("getSessionHandler", Null).RunMethod("getSessionManager", Null)
sessionmanager.RunMethod("setHttpOnly", Array(True))

 

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RemoveServerVersionFromResponses (link)

Private Sub RemoveServerVersionFromResponses (Server As Server)
   Dim jo As JavaObject = Server
   jo = jo.GetField("server")
   Dim connectors() As Object = jo.RunMethod("getConnectors", Null)
   For Each co As JavaObject In connectors
     Dim connections() As Object = co.RunMethodJO("getConnectionFactories", Null).RunMethod("toArray", Null)
     For Each connection As JavaObject In connections
       If GetType(connection) = "org.eclipse.jetty.server.HttpConnectionFactory" Then
         Dim configuration As JavaObject = connection.RunMethod("getHttpConfiguration", Null)
         configuration.RunMethod("setSendServerVersion", Array(False))
       End If
     Next
   Next
End Sub

 

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Stop Running Server (link)

Dim jo As JavaObject = server
jo.GetFieldJO("server").RunMethod("stop", null)

 

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Set Max Idle Time (setIdleTimeout) (link)

srvr.Start
Dim jo As JavaObject = srvr
Dim connectors() As Object = jo.GetFieldJO("server").RunMethod("getConnectors", Null)
Dim timeout As Long = 50000
For Each c As JavaObject In connectors
   c.RunMethod("setIdleTimeout", Array(timeout))
Next

 

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Set Max Text Message Size (setMaxTextMessageSize) (link)

Sub SetMaxTextMessage(size As Int)
   Dim jo As JavaObject = ws
   jo = jo.GetFieldJO("session").RunMethod("getPolicy", Null)
   jo.RunMethod("setMaxTextMessageSize", Array(size))
End Sub

 

[alwaysbusy]

Very useful. Thanks for sharing!

 

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jServer v2.80+ Enabling TLSv1.1 (setIncludeCipherSuites/setExcludeCipherSuites) (link)

Dim jo As JavaObject = ssl
jo.RunMethod("setIncludeCipherSuites", Array(Array As String("TLS_RSA_WITH_AES_128_CBC_SHA")))
jo.RunMethod("setExcludeCipherSuites", Array(Array As String()))

 

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Set Samesite=strict on session cookie

Sub setSameSite()
    'Note 1 - This must be done after webserver.Start
    'Note 2 - This does stop/start the web server
    Dim jo As JavaObject = webserver
    jo.GetFieldJO("server").RunMethod("stop", Null)
    jo.GetFieldJO("context").RunMethodJO("getSessionHandler", Null).RunMethodJO("getSessionCookieConfig", Null).RunMethod("setPath", Array("/;SameSite=strict")) 
    jo.GetFieldJO("server").RunMethod("start", Null)
End Sub

 

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Get the request cipher suite and ssl version (only tested on Server 3)

Sub Handle(req As ServletRequest, resp As ServletResponse)
    If req.Secure Then
        Try
            Dim jo As JavaObject = req
            Dim cipher_suite As String = jo.RunMethod("getAttribute",Array As String("jakarta.servlet.request.cipher_suite"))
            Dim ssl_session As JavaObject = jo.RunMethodJO("getAttribute",Array As String("org.eclipse.jetty.servlet.request.ssl_session"))
            Dim ssl_protocol As String = ssl_session.RunMethod("getProtocol",Null)
        
            Log(ssl_protocol)
            Log(cipher_suite)
        Catch
            Log(LastException)
        End Try       
    End If
    
    'rest of handler
end sub

 

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Set a cookie to be secure (https://en.wikipedia.org/wiki/Secure_cookie)

Dim c As Cookie
c.Initialize("cookiename","cookievalue")
c.MaxAge = 3600
c.HttpOnly = True  
Dim jc As JavaObject = c
jc.RunMethod("setSecure",Array As Object(True))      
resp.AddCookie(c)

And if you need to set SameSite=strict you can append this to the path (there is no out of the box method to do this currently).

Sub SecureCookie(Name As String, Value As String,MaxAge As Int) As Cookie
    Dim c As Cookie
    c.Initialize(Name,Value)
    c.MaxAge = MaxAge
    c.HttpOnly = True
    Dim jc As JavaObject = c
    jc.RunMethod("setSecure",Array As Object(True))
    jc.RunMethod("setPath", Array($"/;SameSite=strict"$))   
    Return c
End Sub

This will give you this in the browser.