CODEWITHSUNDEEP
javamysqlsql
Rainzo78
Rainzo78

Reputation: 51

Cannot save to databases while press button

I have a code of a button from a panel like this :

    try{
        Koneksi objKoneksi = new Koneksi();
        Connection kon = objKoneksi.bukaKoneksi();
        Statement stat = kon.createStatement();
        String query = "insert into transaksi(invoiceno,kode,nama,jumlah,harga,total) values('"
                +Invoice.getText()+"','"
                +Kode.getText()+"','"
                +Nama.getText()+"','"
                +Jumlah.getText()+"','"
                +Harga.getText()+"','"
                +Total.getText()+"','";
        int rows = stat.executeUpdate(query);

        if(rows==1){
            JOptionPane.showMessageDialog(this,"Data sudah tersimpan");
            kon.close();
        }
    }
    catch(SQLException e){}
}

And also a Connection class :

http://pastebin.com/8vZpw9Ek

and statement class :

http://pastebin.com/VK358WJZ

(Sorry for not post the code here. I had some trouble on preformatted text block)

When i hit the button to save the data to databases, here comes the error :

Connection success:
You are not connected to database
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javafinalproject.Aplikasi.SaveActionPerformed(Aplikasi.java:184)
at javafinalproject.Aplikasi.access$200(Aplikasi.java:15)
at javafinalproject.Aplikasi$3.actionPerformed(Aplikasi.java:83)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6516)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6281)
at java.awt.Container.processEvent(Container.java:2229)dd

And Many motre

can someone help me with this? Thanks before

Upvotes: 1

Views: 79

Answers (1)

epoch
epoch

Reputation: 16615

There is an exception occurring here:

catch (Exception ex) {
    System.out.println("You are not connected to database");
    return null;
}

You are suppressing it, you should show it via ex.printStackTrace(). Anyway, the method is then returning null which is causing a NullPointerException here:

Statement stat = kon.createStatement();
// --------------^^^

Update:

Put it here:

catch (Exception ex) {
    System.out.println("You are not connected to database");
    ex.printStackTrace();
    return null;
}

PS: your best bet would be to go talk with your teacher/professor, it seems that you lack the basic understanding necessary to fix this issue.

Upvotes: 2

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