Using SoftReference in ViewHolder pattern in android

Question

I am new to this SoftReference and WeakReference stuff. I am making a generic ViewHolder pattern which keeps all views in Hashtable keyed by View's Id. I decided to use SoftReference for Hashtable and also SoftReference for value of item inside Hashtable.This is my ViewHolder class

public class ListItemTagHolder {
    private int index;
    private SoftReference<java.util.Hashtable<Integer,SoftReference<View>>> views=
            new SoftReference<java.util.Hashtable<Integer,SoftReference<View>>>(
                    new java.util.Hashtable<Integer,SoftReference<View>>());

    public ListItemTagHolder(int index){
        this.index=index;
    }

    public void destroy(){
        java.util.Hashtable<Integer,SoftReference<View>> vals=views.get();
        Enumeration<Integer> ks=vals.keys();
        while(ks.hasMoreElements()){
            vals.get(ks.nextElement()).clear();
        }
        vals.clear();
        views.get().clear();        
        views.clear();
        ks=null;
        vals=null;
    }

    public View getView(int id){
        return views.get().get(id).get();
    }

    public void addView(View v){
        views.get().put(v.getId(),new SoftReference<View>(v));
    }

    public int getIndex(){
        return index;
    }

    public void setIndex(int index){
        this.index=index;
    }
}

I want to know the following

1. Is it correct usage of SoftReference ?

2. What will happen if my activity is destroyed and I am unable to call destroy() method of ListItemTagHolder. Will the memory get cleaned up for Hashtable ?

3. Will all the items in Hashtable be available to me everytime unless all reference to ListItemTagHolder are removed ?