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//: generics/Fill.java

package generics; /* Added by Eclipse.py */

// Generalizing the FilledList idea

// {main: FillTest}

import java.util.*;

// Doesn't work with "anything that has an add()." There is

// no "Addable" interface so we are narrowed to using a

// Collection. We cannot generalize using generics in

// this case.

public class Fill {

public static <T> void fill(Collection<T> collection,

Class<? extends T> classToken, int size) {

for(int i = 0; i < size; i++)

// Assumes default constructor:

try {

collection.add(classToken.newInstance());

} catch(Exception e) {

throw new RuntimeException(e);

}

}

}

class Contract {

private static long counter = 0;

private final long id = counter++;

public String toString() {

return getClass().getName() + " " + id;

}

}

class TitleTransfer extends Contract {}

class FillTest {

public static void main(String[] args) {

List<Contract> contracts = new ArrayList<Contract>();

Fill.fill(contracts, Contract.class, 3);

Fill.fill(contracts, TitleTransfer.class, 2);

for(Contract c: contracts)

System.out.println(c);

SimpleQueue<Contract> contractQueue =

new SimpleQueue<Contract>();

// Won't work. fill() is not generic enough:

// Fill.fill(contractQueue, Contract.class, 3);

}

} /* Output:

Contract 0

Contract 1

Contract 2

TitleTransfer 3

TitleTransfer 4

*///:~