If statement problem!!

[Peter Matthews]

Hi All,

I'm experiencing a strange problem with my if statement. Basically, I'm wanting an error message to come up when a user does not enter a name. However at the moment, the if statement always produces the same result - even if there is no data entered into the txt field. So at the moment, all the respones from the validateText() method are "Good", even when there is no text in the text field. Any help would be very appreciated. Thanks. Pete

  import java.rmi.*;
    import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
 

        public class PumpApplet extends Applet {
          private Button submit = new Button("Submit Order");
          private Label nameLabel = new Label("Customer Name: ");
          private JTextField name = new JTextField("",20);
          private TextArea  status = new TextArea();
          private Label typeLabel = new Label("Pump Type: ");
          private JComboBox typeCombo = new JComboBox(PumpDetails.pumpTypeNames);
          private Label capacityLabel = new Label("Pump Capacity: ");
          private JComboBox capacityCombo = new JComboBox(PumpDetails.capacityNames);
          private Label voltageLabel = new Label("Pump Voltage: ");
          private JComboBox voltageCombo = new JComboBox(PumpDetails.voltageNames);
          private Label quantityLabel = new Label("Quantity: ");
          private JComboBox quantityCombo = new JComboBox(PumpDetails.quantities);
 
          private PumpService obj;
 

  public String validateText(String cust){
 
  if(cust == "") {
 
  return "No good";
 
  } else
 
return "Good";
 
  }
 

          public void init() {
    try {
      obj = (PumpService)Naming.lookup("rmi://localhost/PumpService");
 
        this.add(typeLabel);
              this.add(typeCombo);
              this.add(capacityLabel);
              this.add(capacityCombo);
              this.add(voltageLabel);
              this.add(voltageCombo);
              this.add(quantityLabel);
              this.add(quantityCombo);
              this.add(nameLabel);
              this.add(name);
              this.add(submit);
 

          status.append("ORDER STATUS:\n\n");
 
      submit.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e){
 
  String type = (String) typeCombo.getSelectedItem();
  String capacity = (String) capacityCombo.getSelectedItem();
  String voltage = (String) voltageCombo.getSelectedItem();
  String quantity = (String) quantityCombo.getSelectedItem();
  String cust = (String) name.getText();
 
 try {
 
status.append(cust);
        String val = validateText(cust);
status.append(val);
 

status.append("Sending order...\n");
 
                  String order = "INSERT INTO orders (name,type,capacity,voltage,quantity) " +"values ('"+ cust+"','"+ type +"','"+ capacity+"','"+voltage+ "','"+ quantity+"')";
 
status.append("Customer Name: "+cust+"\nPump Type: "+type+"\nPump Capacity: "+capacity+"\nPump Voltage: "+voltage+"\nQuantity Ordered: "+quantity+"\n");
 
String result = obj.submitOrder(order);
 
status.append(result);
name.setText("");
 

  }
 

 
  catch(Exception e1) {
                    System.out.println("PumpApplet exception :"+e1.getMessage());
                    e1.printStackTrace();
                  }
 

 
                }
 

              });
              this.add(status);
 

    }
    catch (Exception e) {
              System.out.println("PumpApplet exception :" + e.getMessage());
              e.printStackTrace();
            }
          }
        }

[James Swan]

use .equals() to compare your Strings instead of ==

[Jesper de Jong]

String order = "INSERT INTO orders (name,type,capacity,voltage,quantity) " +"values ('"+ cust+"','"+ type +"','"+ capacity+"','"+voltage+ "','"+ quantity+"')";

Appending SQL statements together like that is a bad idea. You should use PreparedStatement. Look it up in the API documentation.

String sql = "INSERT INTO orders (name,type,capacity,voltage,quantity) values (?,?,?,?,?)";
 
PreparedStatement ps = connection.prepareStatement(sql);
 
ps.setString(1, name);
ps.setString(2, type);
ps.setString(3, capacity);
ps.setString(4, voltage);
ps.setString(5, quantity);
 
ps.executeUpdate();

[ November 16, 2005: Message edited by: Jesper de Jong ]

[Pratik Lohia]

hey... cust is a string ... yu cannot use == on that. That will compare references and not the data. Use cust.equals("") instead

[Peter Matthews]

thanks guys - appreciate the help!