java - 如果我在 Java 中使用 HashMap>

Question

我使用HashMap<String, ArrayList<String>>在Java中。

当输入值到来时，

例如输入值为[1, "stack"] , [2, "over"] , [1, "flow"] ......

我要输入值[1, ["stack", "flow"]] , [2, "over"]在 HashMap 中。

但是键值是重复的。所以，HashMap 被覆盖了。

那么，我能做什么？

Answer 1

尝试 Guava Multimap :

The traditional way to represent a graph in Java is Map<V, Set<V>>, which is awkward in a number of ways. Guava's Multimap framework makes it easy to handle a mapping from keys to multiple values.

A ListMultimap will map keys to a List of values, keeping track of their order, while a SetMultimap will map keys to a Set of distinct values.