mapdata.java

Think in Java 4 code 《Think in Java》第4版源码

//: net/mindview/util/MapData.java
// A Map filled with data using a generator object.
package net.mindview.util;
import java.util.*;

public class MapData<K,V> extends LinkedHashMap<K,V> {
  // A single Pair Generator:
  public MapData(Generator<Pair<K,V>> gen, int quantity) {
    for(int i = 0; i < quantity; i++) {
      Pair<K,V> p = gen.next();
      put(p.key, p.value);
    }
  }
  // Two separate Generators:
  public MapData(Generator<K> genK, Generator<V> genV,
      int quantity) {
    for(int i = 0; i < quantity; i++) {
      put(genK.next(), genV.next());
    }
  }
  // A key Generator and a single value:
  public MapData(Generator<K> genK, V value, int quantity){
    for(int i = 0; i < quantity; i++) {
      put(genK.next(), value);
    }
  }
  // An Iterable and a value Generator:
  public MapData(Iterable<K> genK, Generator<V> genV) {
    for(K key : genK) {
      put(key, genV.next());
    }
  }
  // An Iterable and a single value:
  public MapData(Iterable<K> genK, V value) {
    for(K key : genK) {
      put(key, value);
    }
  }
  // Generic convenience methods:
  public static <K,V> MapData<K,V>
  map(Generator<Pair<K,V>> gen, int quantity) {
    return new MapData<K,V>(gen, quantity);
  }
  public static <K,V> MapData<K,V>
  map(Generator<K> genK, Generator<V> genV, int quantity) {
    return new MapData<K,V>(genK, genV, quantity);
  }
  public static <K,V> MapData<K,V>
  map(Generator<K> genK, V value, int quantity) {
    return new MapData<K,V>(genK, value, quantity);
  }
  public static <K,V> MapData<K,V>
  map(Iterable<K> genK, Generator<V> genV) {
    return new MapData<K,V>(genK, genV);
  }
  public static <K,V> MapData<K,V>
  map(Iterable<K> genK, V value) {
    return new MapData<K,V>(genK, value);
  }
} ///:~