Map<Integer, Integer> map = new HashMap<Integer, Integer>();     
 for (Map.Entry<Integer, Integer> entry : map.entrySet()) {  
      System.out.println("Key = " + entry.getKey() + ", Value = " + entry.getValue());     
 }  

Map<Integer, Integer> map = new HashMap<Integer, Integer>();  
//遍历map中的键
for (Integer key : map.keySet()) {  
    System.out.println("Key = " + key);  
}
//遍历map中的值  
for (Integer value : map.values()) {  
    System.out.println("Value = " + value);  
}

Map<Integer, Integer> map = new HashMap<Integer, Integer>();  
Iterator<Map.Entry<Integer, Integer>> entries = map.entrySet().iterator();  
while (entries.hasNext()) {  
    Map.Entry<Integer, Integer> entry = entries.next();  
    System.out.println("Key = " + entry.getKey() + ", Value = " + entry.getValue());  
}
Map map = new HashMap();  
Iterator entries = map.entrySet().iterator();  
while (entries.hasNext()) {  
    Map.Entry entry = (Map.Entry) entries.next();  
    Integer key = (Integer)entry.getKey();  
    Integer value = (Integer)entry.getValue();  
    System.out.println("Key = " + key + ", Value = " + value);  
}

Map<Integer, Integer> map = new HashMap<Integer, Integer>();  
for (Integer key : map.keySet()) {  
    Integer value = map.get(key);  
    System.out.println("Key = " + key + ", Value = " + value);  
}