遍历Map的几种方式

map.forEach((k, v) -> {
    System.out.println(k + " " + v);
});

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

Iterator<Map.Entry<Integer, String>> iterator = map.entrySet().iterator();
while (iterator.hasNext()) {
    Map.Entry<Integer, String> next = iterator.next();
    System.out.println(next.getKey() + " " + next.getValue());
}

for (Integer integer : map.keySet()) {
    System.out.println(integer + " " + map.get(integer));
}

Iterator<Integer> iterator = map.keySet().iterator();
while (iterator.hasNext()) {
    Integer next = iterator.next();
    System.out.println(next + " " + map.get(next));
}

map.entrySet().stream().forEach(entry -> {
    System.out.println(entry.getKey() + " " + entry.getValue());
});

map.entrySet().stream().parallel().forEach(entry -> {
    System.out.println(entry.getKey() + " " + entry.getValue());
});