65 lines
1.6 KiB
Java
65 lines
1.6 KiB
Java
//: generics/coffee/CoffeeGenerator.java
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// ©2015 MindView LLC: see Copyright.txt
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// Generate different types of Coffee:
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package generics.coffee;
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import java.util.*;
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import net.mindview.util.*;
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public class CoffeeGenerator
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implements Generator<Coffee>, Iterable<Coffee> {
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private Class<?>[] types = { Latte.class, Mocha.class,
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Cappuccino.class, Americano.class, Breve.class, };
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private static Random rand = new Random(47);
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public CoffeeGenerator() {}
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// For iteration:
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private int size = 0;
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public CoffeeGenerator(int sz) { size = sz; }
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@Override
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public Coffee next() {
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try {
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return (Coffee)
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types[rand.nextInt(types.length)].newInstance();
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// Report programmer errors at run time:
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} catch(InstantiationException |
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IllegalAccessException e) {
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throw new RuntimeException(e);
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}
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}
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class CoffeeIterator implements Iterator<Coffee> {
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int count = size;
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@Override
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public boolean hasNext() { return count > 0; }
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@Override
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public Coffee next() {
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count--;
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return CoffeeGenerator.this.next();
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}
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@Override
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public void remove() { // Not implemented
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throw new UnsupportedOperationException();
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}
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}
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@Override
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public Iterator<Coffee> iterator() {
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return new CoffeeIterator();
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}
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public static void main(String[] args) {
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CoffeeGenerator gen = new CoffeeGenerator();
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for(int i = 0; i < 5; i++)
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System.out.println(gen.next());
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for(Coffee c : new CoffeeGenerator(5))
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System.out.println(c);
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}
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} /* Output:
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Americano 0
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Latte 1
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Americano 2
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Mocha 3
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Mocha 4
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Breve 5
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Americano 6
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Latte 7
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Cappuccino 8
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Cappuccino 9
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*///:~
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