package thinkinginjava.containers;

// A Map implemented with ArrayLists.

import java.util.AbstractMap;

import java.util.ArrayList;

import java.util.HashSet;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Set;

import thinkinginjava.util.Countries;

public class SlowMap<K, V> extends AbstractMap<K, V> {

private List<K> keys = new ArrayList<K>();

private List<V> values = new ArrayList<V>();

public V put(K key, V value) {

V oldValue = get(key); // The old value or null

if (!keys.contains(key)) {

keys.add(key);

values.add(value);

} else

values.set(keys.indexOf(key), value);

return oldValue;

}

public V get(Object key) { // key is type Object, not K

if (!keys.contains(key))

return null;

return values.get(keys.indexOf(key));

}

public Set<Map.Entry<K, V>> entrySet() {

Set<Map.Entry<K, V>> set = new HashSet<Map.Entry<K, V>>();

Iterator<K> ki = keys.iterator();

Iterator<V> vi = values.iterator();

while (ki.hasNext())

set.add(new MapEntry<K, V>(ki.next(), vi.next()));

return set;

}

public static void main(String[] args) {

SlowMap<String, String> m = new SlowMap<String, String>();

m.putAll(Countries.capitals(15));

System.out.println(m);

System.out.println(m.get("BULGARIA"));

System.out.println(m.entrySet());

}

}