Writing to DB tables

I am trying to write a new record to two database tables which are called item and supplier. I have a class that handles the database connection and SQL statements. I am using a large form in a class called ItemEntryScreen where I am using the following: ``` private void writeItemRecord() { if ( DataBaseHandler.makeConnectionTofireplaceDB() == -1) { JOptionPane.showMessageDialog (frame, "Unable to connect to database table (Item)"); } else // Ok, so first read data from the text fields { // Read data from form and store data String suppliercode = suppliercodeTxtField.getText(); String suppliername = suppliernameTxtField.getText(); String address = addressTxtField.getText(); // Create a Item oject Item item = new Item(); // Set the attributes for the Item object item.setSuppliercode(suppliercode); item.setSuppliername(suppliername); item.setAddress(address); // Write Item record. Method writeToItemTable() returns // 0 of OK writing record, -1 if there is a problem. I store // the returned value in a variable called error. int error = DataBaseHandler.writeTosupplierTable(item.getSuppliercode(),item.getSuppliername(),item.getAddress()); // Check if there is a problem writing the record, in // which case error will contain -1 if (error == -1) { JOptionPane.showMessageDialog (frame, "Problem writing record to Item Table"); } // Clear the form - actual method is coded below clearForm(); // Close database connection. Report an error message // if there is a problem. if ( DataBaseHandler.closeConnection() == -1 ) { JOptionPane.showMessageDialog (frame, "Problem closing data base conection"); } } } /** * Method to write a Item record */ private void writesupplierRecord() { // Check to see if we can connect to database table if ( DataBaseHandler.makeConnectionTofireplaceDB() == -1) { JOptionPane.showMessageDialog (frame, "Unable to connect to database table (Item)"); } else // Ok, so first read data from the text fields { // Read data from form and store data String itemname = itemnameTxtField.getText(); String itemcode = itemcodeTxtField.getText(); String description = descriptionTxtField.getText(); String unitprice = unitpriceTxtField.getText(); String style = styleTxtField.getText(); String finish = finishTxtField.getText(); String stock = stockTxtField.getText(); // Convert priceStr to a float Float fvar = Float.valueOf(unitprice); float newprice = fvar.floatValue(); Float svar = Float.valueOf(stock); float newstock = svar.floatValue(); // Create a Item oject Item item = new Item(); // Set the attributes for the Item object item.setItemname (itemname); item.setItemcode (itemcode); item.setDescription (description); item.setUnitprice (newprice); item.setStock(newstock); item.setStyle(style); item.setFinish(finish); // Write Item record. Method writeToItemTable() returns // 0 of OK writing record, -1 if there is a problem. I store // the returned value in a variable called error. int error = DataBaseHandler.writeToitemTable(item.getItemname(), item.getItemcode(), item.getDescription(), item.getUnitprice(), item.getStock(), item.getStyle(), item.getFinish() ); // Check if there is a problem writing the record, in // which case error will contain -1 if (error == -1) { JOptionPane.showMessageDialog (frame, "Problem writing record to Item Table"); } // Clear the form - actual method is coded below clearForm(); // Close database connection. Report an error message // if there is a problem. if ( DataBaseHandler.closeConnection() == -1 ) { JOptionPane.showMessageDialog (frame, "Problem closing data base conection"); } } } // End ``` The above code compiles! ``` static public int writeToitemTable(String itemnameIn, String itemcodeIn, String descriptionIn, float unitpriceIn, float stockIn, String styleIn, String finishIn) { // Variable to hold the SQL query String SQLString; // Build a string containing the SQL INSERT instruction to be used later SQLString = "INSERT INTO item VALUES ('" + itemcodeIn + "','" + itemnameIn + "','" + descriptionIn + "','" + unitpriceIn + "','" + stockIn + "','" + styleIn + "','" + finishIn + "')"; try { // The createStatement() method creates a Statement object. Object will be // attached to my reference variable (statement) defined at the top of class. statement = connectionTofireplaceDB.createStatement(); // The executeUpdate() statement can be used here to execute an // SQL INSERT instruction. statement.executeUpdate (SQLString); } catch (SQLException exception) { return (-1); // Return -1 if problem writing record to file } return (0); // Return with 0 if record successfully written } // End static public int writeTosupplierTable(String suppliernameIn, String suppliercodeIn, String addressIn) { // Variable to hold the SQL query String SQLString; // Build a string containing the SQL INSERT instruction to be used later SQLString = "INSERT INTO supplier VALUES ('" + suppliernameIn + "','" + suppliercodeIn + "','" + addressIn + "')"; try { // The createStatement() method creates a Statement object. Object will be // attached to my reference variable (statement) defined at the top of class. statement = connectionTofireplaceDB.createStatement(); // The executeUpdate() statement can be used here to execute an // SQL INSERT instruction. statement.executeUpdate (SQLString); } catch (SQLException exception) { return (-1); // Return -1 if problem writing record to file } return (0); // Return with 0 if record successfully written } // End ``` When I enter details into the form and hit the submit button, I am getting a return value of -1 which results in a message box being displayed that states there was a problem writing to the database. Why? Update These are the error messages I can getting: ``` Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at ItemEntryScreen.writeItemRecord(ItemEntryScreen.java:392) at ItemEntryScreen.actionPerformed(ItemEntryScreen.java:348) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387) at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236) at java.awt.Component.processMouseEvent(Component.java:6038) at javax.swing.JComponent.processMouseEvent(JComponent.java:3265) at java.awt.Component.processEvent(Component.java:5803) at java.awt.Container.processEvent(Container.java:2058) at java.awt.Component.dispatchEventImpl(Component.java:4410) at java.awt.Container.dispatchEventImpl(Container.java:2116) at java.awt.Component.dispatchEvent(Component.java:4240) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4322) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3916) at java.awt.Container.dispatchEventImpl(Container.java:2102) at java.awt.Window.dispatchEventImpl(Window.java:2429) at java.awt.Component.dispatchEvent(Component.java:4240) at java.awt.EventQueue.dispatchEvent(EventQueue.java:599) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160) at java.awt.EventDispatchThread.run(EventDispatchThread.java:121) ```