HashMap的getOrDefault()方法
/** * Created by 谭健 2017/8/24. 21:42. * All Rights Reserved */
public static void main(String[] args) {
HashMap<String, Object> hashMap = new HashMap<>();
hashMap.putIfAbsent("orderId", "20170824222735412201");
hashMap.putIfAbsent("userId","1012758623");
hashMap.putIfAbsent("mobilePhone", "15197447018");
hashMap.getOrDefault("orderId", "19700000000000000000");
hashMap.getOrDefault("userId", "1000000000");
hashMap.getOrDefault("mobilePhone", "10000000000");
// old
if (hashMap.containsKey("orderId")) {
String orderId = (String) hashMap.get("orderId");
if (null == orderId || "".equals(orderId)) {
orderId = "19700000000000000000";
}
}
}
– 相较于原来的写法,新的getOrDefault()方法提供一个快捷的方式获取Map中的值
– 他的代码量更少,并且更具有可读性
– 应该推荐getOrDefault()这种写法,他为我们提供了一个更加可靠的代码体验