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Article #19964

Closing Window with dispose. How safe?

#19964
From: John Papadomichelakis
Date: Wed, 19 Nov 1997 00:00
69 lines
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Hi Javers....

One Question which (I guess) it's easy to answer to someone familiar
with Java.

The following function opens the window iw_st_families.
The iw_st_families is an class variable that holds the pointer to
window.
In the Window I call the dispose() function to destroy the object.

But... the object is not destroyed. On a setVisible(true) is enough to
bring it back to life.
I know that this is an incorrect approach and in C++, it could cause a
GPF since the iw_st_families points to memory address that
no longer belongs to the iw_st_families.

However here seems to work correctly.

Since there is always a variable that points to that address, will the
garbage collection destroy ever that object?

 void m_st_families_actionPerformed(ActionEvent e) {
    if(iw_st_families==null){
       iw_st_families = new w_st_families();
       iw_st_families.validate();
       iw_st_families.setVisible(true);
      } else {
      iw_st_families.setVisible(true);
    }
  }
}


--

Papadomichelakis John
"Unite for Java! - http://www.javalobby.org"
__________________________________________________
email : michelos@freemail.gr
URL   : http://users.spark.net.gr:8080/~michelos/
TEL   : 30 31 758 429,       30 31 709 796
__________________________________________________


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From: John Papadomichelakis <michelos@freemail.gr>
Subject: Closing Window with dispose. How safe?
Date: 1997/11/19
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