在 Java 中迭代 MultiMap

问题描述

我有一个如下所示的多地图:

map = {config1=[abc,xyz],config2=[abc]}

现在我尝试使用以下代码对其进行迭代

Iterator<Entry<String,Object>> itr = map.entrySet().iterator();
          while(itr.hasNext()) { 
              Entry<String,Object> entry = itr.next();
              System.out.println("Key = " + entry.getKey() + ",Value = " + entry.getValue()); 
              }

我得到的输出为:

Key = config1,Value = [abc,xyz]
Key = config2,Value = [abc]

但我需要输出为:

Key = config1
Value = abc
Value = xyz
Key = config2
Value = abc

我怎样才能做到这一点?

解决方法

我可以提出这样的建议

public static void main(String[] args) {
    Map<String,Object> map = new HashMap<>();
    String[] arr1 = {"abc","xyz"};
    String[] arr2 = {"abc"};
    map.put("config1",arr1);
    map.put("config2",arr2);

    Iterator<Map.Entry<String,Object>> itr = map.entrySet().iterator();
    while(itr.hasNext()) {
        Map.Entry<String,Object> entry = itr.next();
        System.out.println("entry.getKey() = " + entry.getKey());
        for (Object object: (Object[]) entry.getValue()) {
            System.out.println("object = " + object);
        }
    }
}

然后输出看起来像

entry.getKey() = config2
object = abc
entry.getKey() = config1
object = abc
object = xyz

关键操作是将 String[] 转换为 Object[]