Ok, I haven't run this, but let me try to interpret what I see inline...
Dakota Jack wrote:
Thanks for the response, Paul. Here's what I am up to. I can get an object from the weak reference created from a strong reference. What I want to do, and am not sure if I can (I am starting to think I cannot), is to grab the object with the weak reference and make changes which will happen also with the strong reference. So far, it seems that when I have the object of a weak reference created form a strong reference and change this object, it does not affect the object of the strong reference.
E.g.
package com.crackwillow.deploy;
import java.lang.ref.WeakReference; import java.lang.ref.Reference;
public class MyReference { public static void main(String [] params) { String string = new String("Aaaaaaaaaa");
Created a string containing "Aaaaaaa".
WeakReference wr = new WeakReference(string);
Created a weak reference to said string "Aaaaaa".
wr = replace(wr);
Created a second weak reference to a different string "Baaaaa".
System.out.println(string);
Print "Aaaaaa".
System.out.println(wr);
Print the second weak reference
string = (String)((Reference)wr).get();
Set string to be the second created string "Baaaaa".
System.out.println(string);
Print "Baaaaa".
At least that's what I'd expect it to do.
}
public static WeakReference replace(WeakReference wr) { return new WeakReference(((String)wr.get()).replaceAll("A","B")); } }
Apparently there is no connection between the objects referred to by string and wr in the code shown above.
Well, sure. Because you've replaced your old wr reference with a completely new one containing a completely different String reference.
Is this clearer?
Some things are definitely clearer. ;) -Paul
Jack
On Thu, 02 Dec 2004 02:03:39 -0500, Paul Speed <[EMAIL PROTECTED]> wrote:
A WeakReference is just a way of holding a reference to an object that will not keep it from being garbage collected (a very useful thing). There are also ways that you can track when it has been garbage collected. Once it has been garbage collected, it's gone though. All you have is any data you originally associated with your WeakReference (by subclassing or some other method). You cannot access the referenced object anymore because it doesn't exist.
While the object still exists (ie: is strongly referenced some where), you can still access it through the WeakReference. You just have to expect that at some point you may go to retrieve it from the WeakReference and get a null.
Maybe it would help to know what you are trying to do with it. There are other Reference implementations that may be better suited.
-Paul
Dakota Jack wrote:
Working here on a "new" paradigm, sort of, I think.
Apparently you can track what has happened to a strong reference with a weak reference but you cannot manipulate the object referred to by the strong reference by manipulating the weak reference. Is that right? Seems odd to me.
Jack
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