From Hash Table Remove an Unreferenced Element

**Level8** · 19-02-2010

Hello, I am searching for the program from which I can able to get the solution for the Removing of an Unreferenced Element From hash table. I have tried it to search on internet, but I am not able to get the solution for it. So, if anyone from you knows what is the code to achieve it, then please help me to get it. If you know the reference books or some other source from which I can achieve it, then please help me to get it.

**Praetor** · 19-02-2010

Hello, if you want to remove an Unreferenced Element from the Hash table then you must need to make use of the code below and get your problem solved:

Code:

WeakReference weakReference = new WeakReference(VObj); 
weakMap.put(OObjObject, weakReference); 
obj = weakMap.OObjSet().objerator(); 
while (obj.hasNext()) 
{
Object OObj = obj.next(); 
weakReference = (WeakReference)weakMap.get(OObj); 
if (weakReference == null) 
{  
} 
else
 { 
VObj = weakReference.get(); 
} 
}

**kelfro** · 19-02-2010

Hello, I am not having more knowledge about the hash table, but I know the basic function provided by the Hash Table which are as below:

copy-hash-table
hash-table-count
hash-table-test
hash-table-size
hash-table-rehash-size
hash-table-rehash-threshold
hash-table-weakness

**Zecho** · 19-02-2010

Hello, it is needed to first create a weak map. For creating weak map you need to make use of the following code:

Code:

    Map WMap = new WeakHashMap();   
    WMap.put(objObject, valueObject);   
    Iterator iterator = WMap.objSet().iteratorerator();
    while (iterator.hasNext()) {
        Object obj = iterator.next();
    }

After creating the weakmap you can make use of the code below for removing Hash Table from an Unreferenced Element:

Code:

    WeakReference weakreference = new WeakReference(valueObject);
    WMap.put(objObject, weakreference);
    iterator = WMap.objSet().iteratorerator();
    while (iterator.hasNext()) {
        Object obj = iterator.next();   
        weakreference = (WeakReference)WMap.get(obj);
        if (weakreference == null) {
        } else {
            valueObject = weakreference.get();
        }
    }

**Reegan** · 19-02-2010

Hello, I think you must need to make use of the books on java below for getting exact details about the Hash Table and Unreferenced Elements and removing of it:

Teach Yourself Java in 21 Days by Laura Lemay , Charles Perkins
Java Secrets by Elliotte Rusty Harold
Java Programming for Dummies by David Koosis, Donald J. Koosis
Java for Dummies by Aaron E. Walsh

**Katty** · 19-02-2010

Hey, I have got the code in java for Removing an Unreferenced Element from hash table.

Code:

import java.util.Iterator;
import java.util.Map;
import java.util.WeakHashMap;
public class Main 
{
  public static void main(String[] argv) throws Exception 
{
    Map map = new WeakHashMap();
    Object object = "";
    Object Vobject = "";
    map.put(object, Vobject);
    Iterator iterator = map.keySet().iteratorerator();
    while (iterator.hasNext()) 
{
      Object key = iterator.next();
    }
  }
}