CODEWITHSUNDEEP
java
Sydney Delavin
Sydney Delavin

Reputation: 21

java.lang.NumberFormatException:For input string:""

I am currently working with an attendance management system, but when I click the "save" button this problem shows up 'java.lang.NumberFormatException:For input string:""' Here is my code: 

 try{    
          Class.forName("com.mysql.cj.jdbc.Driver");
          Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/attendance","root","sydneydel");
     String sql = "insert into attendance.student_info values(?,?,?,?,?)";
          PreparedStatement pst = conn.prepareStatement(sql);
          pst.setInt(1,Integer.parseInt(jTextField2.getText()));
          pst.setString(2, last.getText());
          pst.setString(3,first.getText());
          pst.setString(4,mid.getText());

          String gender;
          if (jRadioButton1.isSelected()){
              gender=jRadioButton1.getText();
          }
          else{
               gender=jRadioButton2.getText();
          }
          pst.setString(5, gender);
          pst.executeUpdate();
          JOptionPane.showMessageDialog(null, "SUCCESSFUL");
          conn.close();
         String data1= last.getText();
        String data2= first.getText();
        String data3= mid.getText();
        String data4= gender;
        Object[] row = {1, data2 + " " + data3 + " " + data1, data4};
        model = (DefaultTableModel) table.getModel();
        model.addRow (row);
        first.setText("");
        jTextField2.setText("");
        last.setText("");
        mid.setText("");
        buttonGroup1.clearSelection();
        if((last == null)&& (first==null)&& (buttonGroup1.equals(null))){
            JOptionPane.showMessageDialog(null, "SAVE ERROR\nFill-up the information needed");
        }
        }
        catch(Exception e)

       {       
        JOptionPane.showMessageDialog(null,e);  
                 }    
    }

How can I resolve my problem and how could I improve this program?

Upvotes: 0

Views: 2500

Answers (2)

SIVA POLURI
SIVA POLURI

Reputation: 1

This is my first Answer ;)

String value = "10";
Integer convertedForm = Integer.parseInt(value);

This will works and the value is converted to Integer because value is in number form

But if we pass "" or "abc" like that it can't convert from that to Integer form because we are not passing number. So it will give NumberFormatException.

So handle NumberFormatException , if you pass other then number

Upvotes: 0

Joshua Fox
Joshua Fox

Reputation: 19655

parseInt on the 4th line is receiving an empty string from jTextField2.getText(), and of course that is not parseable as an integer.

Use a debugger to figure out why jTextField2.getText() is blank. Is a number in fact entered in jTextField2?

Upvotes: 1

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