How to do validation using java swing?

[VigneshKarthick]

hi,

i have created 7 textfields and a save button. i want to validate each textfield. the scenario is if any textfield is null or left blank i should get the message box "xyz field should entered" when the save button is clicked.

example,

"class save extends JPanel {
 
        public save() {
            JButton save = new JButton("Save");
            add(save);
            save.addActionListener(new JDBC());
        }
    }"
 
" String exe = "insert into kics.dateframe(date,style,description,fabricgsm,agegroup,size,measurementsunits)values('" + componentTextField.getText() + "','" + TFstyle.getText() + "','" + TFdescription.getText() + "','" + TFfabricGSM.getText() + "','" + TFagegroup.getText() + "','" + TFsize.getText() + "','" + TFmeasurements.getText() + "')";
 
 stmt.executeUpdate(exe);
 

i've tried this code,but its not working,

                if (exe != null) {
                    stmt.executeUpdate(exe);
                } else {
                    JOptionPane.showMessageDialog(null, "xyz fields should be entered");
                }"

regards,
Vignesh Karthick

[horace1]

the getText() method in JTextField returns a String so you could check if it is empty so (assuming exe is a String set up using getText())

if (exe.equals("")) {  
  // string empty
 

or

if (exe.length() == 0) {  
  // string empty
 

[VigneshKarthick]

Hi, This is the real code, database name is kics , table name is dateframe and fields are date, style, description, fabricgsm, agegroup, size, measurementsunits..

Here i want to validate componentTextField, TFstyle, TFdescription, TFfabricGSM, TFagegroup, TFsize, TFmeasurements; if these fields are null or left blank and click the save button, i must get the message box as "XYZ(date,style....) field should be entered".

Here where should i need to apply validation codes.

public class dateFrame extends JFrame { 
 
JTextField componentTextField = new JTextField(); 
JTextField TFstyle; 
JTextField TFdescription; 
JTextField TFfabricGSM; 
JTextField TFagegroup; 
JTextField TFsize; 
JTextField TFmeasurements; 
 
public static void main(String[] args) { 
dateFrame df = new dateFrame(); 
} 
 
public dateFrame() { 
super("Date Frame"); 
dateFramePanel dfp = new dateFramePanel(); 
save s = new save(); 
getContentPane().add(dfp, BorderLayout.PAGE_START); 
getContentPane().add(s, BorderLayout.SOUTH); 
pack(); 
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
setLocation(350, 250); 
setResizable(false); 
setVisible(true); 
} 
 
class dateFramePanel extends JPanel { 
 
DateChooser dc = new DateChooser(); 
 
public dateFramePanel() { 
super(new GridLayout(0, 2)); 
JLabel Ldate = new JLabel("Date"); 
JLabel Lstyle = new JLabel("Style"); 
JLabel Ldescription = new JLabel("Description"); 
JLabel LfabricGSM = new JLabel("Fabric & GSM"); 
JLabel Lagegroup = new JLabel("Age group"); 
JLabel Lsize = new JLabel("Size"); 
JLabel Lmeasurements = new JLabel("Measurement units (CM / INCH)"); 
 
TFstyle = new JTextField(10); 
TFdescription = new JTextField(10); 
TFfabricGSM = new JTextField(10); 
TFagegroup = new JTextField(10); 
TFsize = new JTextField(10); 
TFmeasurements = new JTextField(10); 
 
add(Ldate); 
add(dc); 
add(Lstyle); 
add(TFstyle); 
add(Ldescription); 
add(TFdescription); 
add(LfabricGSM); 
add(TFfabricGSM); 
add(Lagegroup); 
add(TFagegroup); 
add(Lsize); 
add(TFsize); 
add(Lmeasurements); 
add(TFmeasurements); 
 
setPreferredSize(new Dimension(700, 200)); 
} 
} 
 
class save extends JPanel { 
 
public save() { 
JButton save = new JButton("Save"); 
add(save); 
save.addActionListener(new JDBC()); 
} 
} 
 
class JDBC implements ActionListener { 
 
public void actionPerformed(ActionEvent e) { 
Connection con = null; 
Statement stmt; 
String loadDriver = "sun.jdbc.odbc.JdbcOdbcDriver"; 
try { 
Class.forName(loadDriver); 
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/kics", "root", ""); 
stmt = con.createStatement(); 
String exe = "insert into kics.dateframe(date,style,description,fabricgsm,agegroup,size,measurementsunits)values('" + componentTextField.getText() + "', 
 
'"+ TFstyle.getText() + "','" + TFdescription.getText() + "','" + TFfabricGSM.getText() + "','" + TFagegroup.getText() + "','"+ TFsize.getText() + "', 
 
'"+ TFmeasurements.getText() + "')"; 
 
stmt.executeUpdate(exe); 
 
 
} catch (Exception e1) { 
System.out.println("Exception found"); 
System.err.println(e1.getMessage()); 
} finally { 
try { 
con.close(); 
} catch (Exception e1) { 
System.out.println("Exception found"); 
System.err.print(e1.getMessage()); 
} 
} 
} 
}

[horace1]

if I have JTextField and a JButton and when I click the button I check that there is text in textfiled the JButton actionPerformed() method looks like

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
        if(jTextField1.getText().length()==0)
            JOptionPane.showMessageDialog(null, "enter text in textfield");
        else
            JOptionPane.showMessageDialog(null, "textfield is " + jTextField1.getText());
    }
 

[VigneshKarthick]

Thank you horace1.. your idea is working. now i can implement this into my code...