Java 如何判断列表是否包含映射键

Java 如何判断列表是否包含映射键,java,map,linked-list,Java,Map,Linked List,我试图编写一个while循环,该循环将继续迭代,直到节点列表在其映射中没有某个键为止。我的代码如下所示: List<Map<Integer, Integer>> nodes = new LinkedList<Map<Integer, Integer>>(); List<Integer> parent = new LinkedList<Integer>(); . . . while (parent != null) {

我试图编写一个while循环,该循环将继续迭代,直到节点列表在其映射中没有某个键为止。我的代码如下所示:

List<Map<Integer, Integer>> nodes = new LinkedList<Map<Integer, Integer>>();
List<Integer> parent = new LinkedList<Integer>();
.
.
.
while (parent != null) {
        int vertex = parent.remove(0);
        while(//The problem )
    }
}

我将从父节点中提取整数并将其放入顶点,然后使用顶点在节点中查找关键点。在节点中查找整数的调用是什么样子的?

我不确定这是否是您想要的,但可能是

    List<Map<Integer, Integer>> nodes = new LinkedList<Map<Integer, Integer>>();
    LinkedList<Integer> parent = new LinkedList<Integer>();
    // ^ or Queue to use .poll() which removes the first item

    Integer parentItem;
    while ((parentItem = parent.poll()) != null) {
        // check if that item is somewhere in the maps
        boolean inMaps = false;
        for(Map<Integer, Integer> map : nodes) {
            if (map.containsKey(parentItem)) {
                inMaps = true;
                break;
            }
        }
        // if it is not do something special, maybe "return" or "break;"
        if (!inMaps) {
            // do something.
        }
    }
这可能会有帮助

for(int vertex: parent) {
   for(Map<Integer, Integer) entry : nodes) {
      if(entry.contains(vertex) {
         //the map entry has the key, write your logic and return
         return entry
      }
   }
}