stuck with sqlite transaction using java

try {
    stmt = con.createStatement();
    stmt.getConnection().setAutoCommit(false);
    try {
        for (String q : query) {
            if (q != null && !q.equals("")) {
                  stmt.executeUpdate(q);
            }
        }
        stmt.execute("COMMIT");
        stmt.getConnection().setAutoCommit(true);
        stmt.close();
        JOptionPane.showMessageDialog(frame, "Details Successfully Added.",
         "Information", JOptionPane.INFORMATION_MESSAGE);
    } catch (SQLException ex) {
         System.out.println("Rollback:\n " ex.getMessage());
         stmt.execute("ROLLBACK");
    }
} catch (SQLException ex) {
      JOptionPane.showMessageDialog(frame,ex.getMessage(),
         "Exception Occured", JOptionPane.ERROR_MESSAGE);
}

i have written above code to insert multiple records using transaction, but when i execute it, it sometimes gives me could not commit no transaction is running and sometimes could not rollback no transaction is active while the records are successfully getting inserted.

as i am new to sqlite and java, i am not getting what is the actual issue here, please anyone guide me or help me to make it run..