Code:

Class.forName("org.apache.derby.jdbc.EmbeddedDriver").newInstance(); //greska!

Exception in thread "main" java.lang.ExceptionInInitializerError
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Unknown Source)
    at dbase.DBConnection.<init>(DBConnection.java:15)
    at dbase.DBConnection.getInstance(DBConnection.java:27)
    at test.Test.main(Test.java:12)
Caused by: java.lang.NullPointerException
    at org.apache.derby.impl.services.monitor.BaseMonitor.getDefaultImplementations(BaseMonitor.java)
    at org.apache.derby.impl.services.monitor.BaseMonitor.runWithState(BaseMonitor.java)
    at org.apache.derby.impl.services.monitor.FileMonitor.<init>(FileMonitor.java)
    at org.apache.derby.iapi.services.monitor.Monitor.startMonitor(Monitor.java)
    at org.apache.derby.iapi.jdbc.JDBCBoot.boot(JDBCBoot.java)
    at org.apache.derby.jdbc.EmbeddedDriver.boot(EmbeddedDriver.java)
    at org.apache.derby.jdbc.EmbeddedDriver.<clinit>(EmbeddedDriver.java)
    ... 5 more