Java泛型Map

package com.codingdict;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

public class GenericsTester {
   public static void main(String[] args) {

      Map<Integer,Integer> integerMap
         = new HashMap<Integer,Integer>();

      integerMap.put(1, 10);
      integerMap.put(2, 11);

      Map<String,String> stringMap
         = new HashMap<String,String>();

      stringMap.put("1", "Hello World");
      stringMap.put("2","Hi World");


      System.out.printf("Integer Value :%d\n", integerMap.get(1));
      System.out.printf("String Value :%s\n", stringMap.get("1"));

      // iterate keys.
      Iterator<Integer> integerIterator   = integerMap.keySet().iterator();

      while(integerIterator.hasNext()){
         System.out.printf("Integer Value :%d\n", integerIterator.next());
      }

      // iterate values.
      Iterator<String> stringIterator   = stringMap.values().iterator();

      while(stringIterator.hasNext()){
         System.out.printf("String Value :%s\n", stringIterator.next());
      }
   }  
}