java implementation for http://stackoverflow.com/questions/13878944/how-to-handle-a-collection-of-foot-where-t-can-be-different-for-each-item

gistfile1.java

import java.util.*;
import java.lang.*;
import static java.lang.System.out;
 
class Main
{
    public static void main (String[] args) throws java.lang.Exception
    {
        List<Pair<?>> lst = new ArrayList<Pair<?>>();
        lst.add(new Pair<String>("a","b"));
        lst.add(new Pair<Integer>(1,2));
        
        Application.SwapAll(lst);
        
        for(Pair<?> pair: lst) out.println(pair);            
    }
}
 
class Pair<T> {
    T First, Second;
 
    public Pair(T First, T Second) {
        this.First=First;
        this.Second=Second;
    }
    
    public String toString() {
        return String.format("(%s, %s)",First.toString(),Second.toString());
    }
}
 
class Application {
    public static <T> void Swap(Pair<T> pair) {
        T temp=pair.Second; 
        pair.Second = pair.First;
        pair.First = temp;
    }
    
    public static void SwapAll(List<Pair<?>> lst) {
        for(Pair<?> pair: lst) Application.Swap(pair);        
    }
}