slowmap.java

Java编程思想 第九课 全源码

//: c09:SlowMap.java
// From 'Thinking in Java, 2nd ed.' by Bruce Eckel
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
// A Map implemented with ArrayLists.
import java.util.*;
import com.bruceeckel.util.*;

public class SlowMap extends AbstractMap {
  private ArrayList 
    keys = new ArrayList(),
    values = new ArrayList();
  public Object put(Object key, Object value) {
    Object result = get(key);
    if(!keys.contains(key)) {
      keys.add(key);
      values.add(value);
    } else
      values.set(keys.indexOf(key), value);
    return result;
  }
  public Object get(Object key) {
    if(!keys.contains(key))
      return null;
    return values.get(keys.indexOf(key));
  }
  public Set entrySet() {
    Set entries = new HashSet();
    Iterator
      ki = keys.iterator(),
      vi = values.iterator();
    while(ki.hasNext())
      entries.add(new MPair(ki.next(), vi.next()));
    return entries;
  }
  public static void main(String[] args) {
    SlowMap m = new SlowMap();
    Collections2.fill(m, 
      Collections2.geography, 25);
    System.out.println(m);
    System.out.println(m.put("BOTSWANA","aa"));
    System.out.println(m.get("ss"));
    System.out.println(m.hashCode());
  }
} ///:~