"jdbc:h2:~/aleksei"

java.lang.NullPointerException
at gui.GUI.initialize(GUI.java:89)
at gui.GUI.<init>(GUI.java:71)
at gui.GUI$1.run(GUI.java:58)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

JLabel topicName = new JLabel(topicService.getById(1L).getName());

private DataSource initiateDataSource() {
    BasicDataSource  bds = new BasicDataSource();
    //bds.setUrl("jdbc:h2:~/aleksei"); этот вариант работает, но только на моем pc (на других - npe)
    bds.setUrl("jdbc:h2:file:/aleksei");//пробую этот вариант, чтоб работала на других компьютерах, но в таком случае даже у меня вылетает npe.
    bds.setUsername("aleksei");
    bds.setPassword("");
    return bds;
}