java1.8map循环遍历key value

一 . Map.keySet遍历key和value
for (String key : map.keySet()) {
System.out.println("map.get(" + key + ") = " + map.get(key));
}
map.keySet().forEach(key -> System.out.println("map.get(" + key + ") = " + map.get(key)));

二.Iterator遍历key和value
Iterator<Map.Entry<String, Object>> iterator = map.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry<String, Object> entry = iterator.next();
System.out.println("key:value = " + entry.getKey() + ":" + entry.getValue());
}
map.entrySet().iterator().forEachRemaining(item -> System.out.println("key:value=" + item.getKey() + ":" + item.getValue()));

三.Map.entrySet
for (Map.Entry<String, Object> entry : map.entrySet()) {
System.out.println("key:value = " + entry.getKey() + ":" + entry.getValue());
}
map.entrySet().forEach(entry -> System.out.println("key:value = " + entry.getKey() + ":" + entry.getValue()));

四.Map.values()遍历所有的value，但不能遍历key
for (Object value : map.values()) {
System.out.println("map.value = " + value);
}
map.values().forEach(System.out::println); // 等价于map.values().forEach(value -> System.out.println(value));

 五.通过k,v遍历，1.8
map.forEach((k, v) -> System.out.println("key:value = " + k + ":" + v));