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Groups > comp.lang.java.programmer > #15197

Re: It doesn't like 'super' where ever I put it.

From Lew <noone@lewscanon.com>
Newsgroups comp.lang.java.programmer
Subject Re: It doesn't like 'super' where ever I put it.
Date 2012-06-10 13:56 -0700
Organization albasani.net
Message-ID <jr31lk$rrp$1@news.albasani.net> (permalink)
References <jr27ce$7uo$1@dont-email.me>

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bilsch wrote:
> Hello, below is my program stripped to bare bones. Java says 'super' must be
> first statement in constructor. I've moved it everywhere still no luck. The
> program was running yesterday and I can't figure what could be wrong. Any
> suggestions?
>
> The error output is listed below the program
>
> TIA Bill S.
>
>
> PROGRAM:
>
> import javax.swing.*;
> import java.awt.*;
> import java.util.*;
>
> public class CalcFrame1 extends JFrame{
>
>  public void CalcFrame1() {

Everyone else has told you of the difference a 'void' makes.

You asked where this is taught so you can learn it. The Java tutorial is the 
canonical starting place.

<http://docs.oracle.com/javase/tutorial/>
particularly
<http://docs.oracle.com/javase/tutorial/java/javaOO/constructors.html>

>    super("CalcFrame1");
>    //setTitle("CalcFrame1");
>    FlowLayout flo = new FlowLayout();
>    setLayout(flo);
>    setLookAndFeel();
>    //setSize(600,600);
>
>    JButton shf = new JButton("shft");
>    JButton chs = new JButton("chs");
>    add (shf);
>    add (chs);
>
>    pack();
>    setVisible(true);

Don't 'setVisible()' in the constructor. Constructors, as the name implies, 
are for construction of an object, but not its operation.

Let the object finish building itself completely before anything else can get 
to it.

>  }
>  private void setLookAndFeel(){
>    try{
>      UIManager.setLookAndFeel(
>      "com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
>    }
>    catch(Exception exc){

Don't catch just 'Exception' here, but the exact exceptions you are required 
to catch.

>      // ignore error

And *never* ignore errors!

>    }
> }
>
>  public static void main(String[] args){
>    CalcFrame1 ClFr1 = new CalcFrame1();

Oops. You didn't start this on the EDT (Event Dispatch Thread). (And you don't 
let the object finish construction before things can get to it.)

The Swing tutorial (ibid.) explains this a little bit.

-- 
Lew
Honi soit qui mal y pense.
http://upload.wikimedia.org/wikipedia/commons/c/cf/Friz.jpg

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Thread

It doesn't like 'super' where ever I put it. bilsch <bilsch01@gmail.com> - 2012-06-10 06:27 -0700
  Re: It doesn't like 'super' where ever I put it. v_borchert@despammed.com (Volker Borchert) - 2012-06-10 13:49 +0000
    Re: It doesn't like 'super' where ever I put it. bilsch <bilsch01@gmail.com> - 2012-06-10 07:08 -0700
      Re: It doesn't like 'super' where ever I put it. Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-10 11:34 -0400
        Re: It doesn't like 'super' where ever I put it. bilsch <bilsch01@gmail.com> - 2012-06-10 12:58 -0700
          Re: It doesn't like 'super' where ever I put it. markspace <-@.> - 2012-06-10 13:43 -0700
            Re: It doesn't like 'super' where ever I put it. bilsch <bilsch01@gmail.com> - 2012-06-11 21:01 -0700
      Re: It doesn't like 'super' where ever I put it. v_borchert@despammed.com (Volker Borchert) - 2012-06-10 15:44 +0000
    Re: It doesn't like 'super' where ever I put it. Robert Klemme <shortcutter@googlemail.com> - 2012-06-10 20:39 +0200
      Re: It doesn't like 'super' where ever I put it. "Gavino" <invalid@invalid.invalid> - 2012-06-11 20:13 +0200
        Re: It doesn't like 'super' where ever I put it. Robert Klemme <shortcutter@googlemail.com> - 2012-06-11 22:51 +0200
          Re: It doesn't like 'super' where ever I put it. "Gavino" <invalid@invalid.invalid> - 2012-06-12 00:45 +0200
            Re: It doesn't like 'super' where ever I put it. Martin Gregorie <martin@address-in-sig.invalid> - 2012-06-11 22:53 +0000
              Re: It doesn't like 'super' where ever I put it. Lew <lewbloch@gmail.com> - 2012-06-11 16:42 -0700
            Re: It doesn't like 'super' where ever I put it. Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-11 19:53 -0400
              Re: It doesn't like 'super' where ever I put it. Lew <lewbloch@gmail.com> - 2012-06-11 17:38 -0700
                Re: It doesn't like 'super' where ever I put it. "John B. Matthews" <nospam@nospam.invalid> - 2012-06-11 23:14 -0400
                Re: It doesn't like 'super' where ever I put it. Robert Klemme <shortcutter@googlemail.com> - 2012-06-12 18:21 +0200
      Re: It doesn't like 'super' where ever I put it. Robert Klemme <shortcutter@googlemail.com> - 2012-06-11 22:50 +0200
  Re: It doesn't like 'super' where ever I put it. Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-10 09:59 -0400
  Re: It doesn't like 'super' where ever I put it. Jim Janney <jjanney@shell.xmission.com> - 2012-06-10 08:02 -0600
    Re: It doesn't like 'super' where ever I put it. bilsch <bilsch01@gmail.com> - 2012-06-10 07:20 -0700
      Re: It doesn't like 'super' where ever I put it. Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-06-10 09:49 -0500
        Re: It doesn't like 'super' where ever I put it. bilsch <bilsch01@gmail.com> - 2012-06-10 13:15 -0700
      Re: It doesn't like 'super' where ever I put it. Jim Janney <jjanney@shell.xmission.com> - 2012-06-10 10:26 -0600
        Re: It doesn't like 'super' where ever I put it. Jim Janney <jjanney@shell.xmission.com> - 2012-06-10 11:24 -0600
        Re: It doesn't like 'super' where ever I put it. Jim Janney <jjanney@shell.xmission.com> - 2012-06-10 11:38 -0600
          Re: It doesn't like 'super' where ever I put it. v_borchert@despammed.com (Volker Borchert) - 2012-06-10 18:17 +0000
            Re: It doesn't like 'super' where ever I put it. Lew <noone@lewscanon.com> - 2012-06-10 12:26 -0700
        Re: It doesn't like 'super' where ever I put it. bilsch <bilsch01@gmail.com> - 2012-06-10 13:17 -0700
  Re: It doesn't like 'super' where ever I put it. Roedy Green <see_website@mindprod.com.invalid> - 2012-06-10 11:54 -0700
    Re: It doesn't like 'super' where ever I put it. bilsch <bilsch01@gmail.com> - 2012-06-10 13:24 -0700
  Re: It doesn't like 'super' where ever I put it. Lew <noone@lewscanon.com> - 2012-06-10 13:56 -0700
    Re: It doesn't like 'super' where ever I put it. bilsch <bilsch01@gmail.com> - 2012-06-11 20:55 -0700
  Re: It doesn't like 'super' where ever I put it. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-11 16:41 -0700

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