CODEWITHSUNDEEP
javaswingif-statement
Manoj Kumar
Manoj Kumar

Reputation: 21

If statement is not working with my swing application

I am a java beginner, i wrote this application using netbeans. Its purpose is to get the entered value from the textbox and display it in a message box when i press the button. It works fine when i give the value in the textbox. When i press the button with out giving a value it is suppose to display nothing, but it displays an empty message box. So please help me to fix the problem.

private void ChecktheloopActionPerformed(java.awt.event.ActionEvent evt) {                                             
       String recno= numsearch1.getText();   
       String srname=searchname.getText();
       if(recno!=null){
       JOptionPane.showMessageDialog(null,recno);
   }
}

Upvotes: 1

Views: 149

Answers (3)

Amin Abu-Taleb
Amin Abu-Taleb

Reputation: 4511

You have to check if text is an empty string, using isEmpty() method of String class: 

private void ChecktheloopActionPerformed(java.awt.event.ActionEvent evt) {                                             
           String recno= numsearch1.getText();   
           String srname=searchname.getText();
           if(!recno.isEmpty()){
                JOptionPane.showMessageDialog(null,recno);
           }
      }

Upvotes: 0

Bonifacio2
Bonifacio2

Reputation: 3840

You also have to check if the string is equals to "" before showing the dialog box.

private void ChecktheloopActionPerformed(java.awt.event.ActionEvent evt) {                                             
    String recno= numsearch1.getText();   
    String srname=searchname.getText();
    if(!recno.equals("")){
        JOptionPane.showMessageDialog(null,recno);
    }
}

numsearch1.getText(); is probably returning an empty string instead of the null you were expecting.

Upvotes: 0

AmirtharajCVijay
AmirtharajCVijay

Reputation: 1108

try it

private void ChecktheloopActionPerformed(java.awt.event.ActionEvent evt) {                                             
           String recno= numsearch1.getText();   
           String srname=searchname.getText();
           if(recno!=null && recno.trim().length()>0){
           JOptionPane.showMessageDialog(null,recno);
       }
    }

Upvotes: 1

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