German java.lang.reflect.InvocationTargetException

#AdditionalJar: mariadb-java-client-3.5.1.jar

Sub ConnectToMariaDB(jdbcURL As String, username As String, password As String) As JavaObject
    Dim driver As JavaObject
    driver.InitializeNewInstance("org.mariadb.jdbc.Driver", Null)
    Dim connection As JavaObject = driver.RunMethod("connect", Array(jdbcURL, CreateCredentials(username, password)))
    Return connection
End Sub

Sub CreateCredentials(username As String, password As String) As JavaObject
    Dim properties As JavaObject
    properties.InitializeNewInstance("java.util.Properties", Null)
    properties.RunMethod("setProperty", Array("user", username))
    properties.RunMethod("setProperty", Array("password", password))
    Return properties
End Sub

Private Sub B4XPage_Created (Root1 As B4XView)

Try
    Dim jdbcURL As String = "jdbc:mariadb://localhost/mydb"
    sqlConnection = ConnectToMariaDB(jdbcURL, "username", "password")
Catch
    Log(LastException)
End Try

java.lang.reflect.InvocationTargetException
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4j.object.JavaObject.RunMethod(JavaObject.java:132)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:348)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:157)
    at anywheresoftware.b4a.debug.Debug.delegate(Debug.java:262)
    at b4a.program.b4xmainpage._connecttomariadb(b4xmainpage.java:101)
    at b4a.program.b4xmainpage._b4xpage_created(b4xmainpage.java:86)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.debug.Debug.CallSub4(Debug.java:318)
    at anywheresoftware.b4a.debug.Debug.CallSubNew2(Debug.java:285)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.keywords.Common.CallSubDebug2(Common.java:1087)
    at b4a.program.b4xpagesmanager._createpageifneeded(b4xpagesmanager.java:1068)
    at b4a.program.b4xpagesmanager._showpage(b4xpagesmanager.java:425)
    at b4a.program.b4xpagesmanager._addpage(b4xpagesmanager.java:245)
    at b4a.program.b4xpagesmanager._addpageandcreate(b4xpagesmanager.java:259)
    at b4a.program.b4xpagesmanager._initialize(b4xpagesmanager.java:165)
    at b4a.program.main._activity_create(main.java:415)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:351)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:157)
    at b4a.program.main.afterFirstLayout(main.java:105)
    at b4a.program.main.access$000(main.java:17)
    at b4a.program.main$WaitForLayout.run(main.java:83)
    at android.os.Handler.handleCallback(Handler.java:873)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:6669)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: java.sql.SQLNonTransientConnectionException: Socket fail to connect to localhost. failed to connect to localhost/127.0.0.1 (port 3306) from /127.0.0.1 (port 32864) after 30000ms: isConnected failed: ECONNREFUSED (Connection refused)
    at org.mariadb.jdbc.client.impl.ConnectionHelper.connectSocket(ConnectionHelper.java:131)
    at org.mariadb.jdbc.client.impl.StandardClient.<init>(StandardClient.java:127)
    at org.mariadb.jdbc.Driver$$ExternalSyntheticLambda1.apply(D8$$SyntheticClass:0)
    at org.mariadb.jdbc.Driver.connect(Driver.java:73)
    at org.mariadb.jdbc.Driver.connect(Driver.java:102)
    at org.mariadb.jdbc.Driver.connect(Driver.java:27)
    ... 38 more
Caused by: java.net.ConnectException: failed to connect to localhost/127.0.0.1 (port 3306) from /127.0.0.1 (port 32864) after 30000ms: isConnected failed: ECONNREFUSED (Connection refused)
    at libcore.io.IoBridge.isConnected(IoBridge.java:278)
    at libcore.io.IoBridge.connectErrno(IoBridge.java:187)
    at libcore.io.IoBridge.connect(IoBridge.java:129)
    at java.net.PlainSocketImpl.socketConnect(PlainSocketImpl.java:137)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:390)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:230)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:212)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:436)
    at java.net.Socket.connect(Socket.java:621)
    at org.mariadb.jdbc.client.impl.ConnectionHelper.connectSocket(ConnectionHelper.java:118)
    ... 43 more
Caused by: android.system.ErrnoException: isConnected failed: ECONNREFUSED (Connection refused)
    at libcore.io

#AdditionalJar: mysql-connector-java-5.1.34-bin

Sub Class_Globals
    Private Root As B4XView
    Private xui As XUI
    Public db As SQL
End Sub
Private Sub B4XPage_Created (Root1 As B4XView)
    Root = Root1
    Root.LoadLayout("MainPage")
    db.InitializeAsync("DB","com.mysql.jdbc.Driver", "jdbc:mysql://host:port/dbname?characterEncoding=utf8&autoReconnect=true","username","passwort")

End Sub
Sub DB_Ready (Success As Boolean)
    If Success = False Then
        Return
    End If
  ' Mach was immer du willst mit der Datenbank...
END sub