map1.java

java编程思想的源码,11-16,和上次上传的1-10的源码是一块的,希望大家都能学好java

//: c11:Map1.java
// Things you can do with Maps.
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
import java.util.*;
import com.bruceeckel.util.*;

public class Map1 {
  private static Collections2.StringPairGenerator geo =
    Collections2.geography;
  private static Collections2.RandStringPairGenerator
    rsp = Collections2.rsp;
  // Producing a Set of the keys:
  public static void printKeys(Map map) {
    System.out.print("Size = " + map.size() + ", ");
    System.out.print("Keys: ");
    System.out.println(map.keySet());
  }
  public static void test(Map map) {
    // Strip qualifiers from class name:
    System.out.println(
      map.getClass().getName().replaceAll("\\w+\\.", ""));
    Collections2.fill(map, geo, 25);
    // Map has 'Set' behavior for keys:
    Collections2.fill(map, geo.reset(), 25);
    printKeys(map);
    // Producing a Collection of the values:
    System.out.print("Values: ");
    System.out.println(map.values());
    System.out.println(map);
    String key = CountryCapitals.pairs[4][0];
    String value = CountryCapitals.pairs[4][1];
    System.out.println("map.containsKey(\"" + key +
      "\"): " + map.containsKey(key));
    System.out.println("map.get(\"" + key + "\"): "
      + map.get(key));
    System.out.println("map.containsValue(\""
      + value + "\"): " + map.containsValue(value));
    Map map2 = new TreeMap();
    Collections2.fill(map2, rsp, 25);
    map.putAll(map2);
    printKeys(map);
    key = map.keySet().iterator().next().toString();
    System.out.println("First key in map: " + key);
    map.remove(key);
    printKeys(map);
    map.clear();
    System.out.println("map.isEmpty(): " + map.isEmpty());
    Collections2.fill(map, geo.reset(), 25);
    // Operations on the Set change the Map:
    map.keySet().removeAll(map.keySet());
    System.out.println("map.isEmpty(): " + map.isEmpty());
  }
  public static void main(String[] args) {
    test(new HashMap());
    test(new TreeMap());
    test(new LinkedHashMap());
    test(new IdentityHashMap());
    test(new WeakHashMap());
  }
} ///:~