HashMap遍历

1.直接遍历输出

for (Map.Entry<String, Integer> entry : hashMap.entrySet()) {
    System.out.println(entry.getKey() + ":" + entry.getValue());
}

2.利用迭代器遍历输出

Set<Map.Entry<String, Integer>> set = hashMap.entrySet();
Iterator iterator = set.iterator();
while (iterator.hasNext()){
    Map.Entry entry = (Map.Entry) iterator.next();
    System.out.print(entry.getKey()+":"+entry.getValue());
}