46 lines
1.8 KiB
Java
46 lines
1.8 KiB
Java
//: containers/SlowMap.java
|
|
// A Map implemented with ArrayLists.
|
|
import java.util.*;
|
|
import net.mindview.util.*;
|
|
|
|
public class SlowMap<K,V> extends AbstractMap<K,V> {
|
|
private List<K> keys = new ArrayList<>();
|
|
private List<V> values = new ArrayList<>();
|
|
@Override
|
|
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;
|
|
}
|
|
@Override
|
|
public V get(Object key) { // key is type Object, not K
|
|
if(!keys.contains(key))
|
|
return null;
|
|
return values.get(keys.indexOf(key));
|
|
}
|
|
@Override
|
|
public Set<Map.Entry<K,V>> entrySet() {
|
|
Set<Map.Entry<K,V>> set= new HashSet<>();
|
|
Iterator<K> ki = keys.iterator();
|
|
Iterator<V> vi = values.iterator();
|
|
while(ki.hasNext())
|
|
set.add(new MapEntry<>(ki.next(), vi.next()));
|
|
return set;
|
|
}
|
|
public static void main(String[] args) {
|
|
SlowMap<String,String> m= new SlowMap<>();
|
|
m.putAll(Countries.capitals(15));
|
|
System.out.println(m);
|
|
System.out.println(m.get("BULGARIA"));
|
|
System.out.println(m.entrySet());
|
|
}
|
|
} /* Output:
|
|
{CHAD=N'djamena, ALGERIA=Algiers, BOTSWANA=Gaberone, BURUNDI=Bujumbura, CONGO=Brazzaville, DJIBOUTI=Dijibouti, COMOROS=Moroni, EQUATORIAL GUINEA=Malabo, ANGOLA=Luanda, EGYPT=Cairo, CAPE VERDE=Praia, BURKINA FASO=Ouagadougou, BENIN=Porto-Novo, CENTRAL AFRICAN REPUBLIC=Bangui, CAMEROON=Yaounde}
|
|
null
|
|
[CHAD=N'djamena, ALGERIA=Algiers, BOTSWANA=Gaberone, BURUNDI=Bujumbura, CONGO=Brazzaville, DJIBOUTI=Dijibouti, COMOROS=Moroni, EQUATORIAL GUINEA=Malabo, ANGOLA=Luanda, EGYPT=Cairo, CAPE VERDE=Praia, BURKINA FASO=Ouagadougou, BENIN=Porto-Novo, CENTRAL AFRICAN REPUBLIC=Bangui, CAMEROON=Yaounde]
|
|
*///:~
|