在java中将ArrayList添加到另一个ArrayList [英] Add ArrayList to another ArrayList in java

问题描述

我有以下 java 代码，其中我试图将 ArrayList 复制到另一个 ArrayList.

I am having the following java code, in which I am trying to copy the ArrayList to another ArrayList.

ArrayList<String> nodes = new ArrayList<String>();
ArrayList NodeList = new ArrayList();
ArrayList list = new ArrayList();

for (int i = 0; i < PropertyNode.getLength() - 1; i++) {
    Node childNode = PropertyNode.item(i);
    NodeList Children = childNode.getChildNodes();

    if (Children != null) {
        nodes.clear();
        nodes.add("PropertyStart");
        nodes.add(Children.item(3).getTextContent());
        nodes.add(Children.item(7).getTextContent());
        nodes.add(Children.item(9).getTextContent());
        nodes.add(Children.item(11).getTextContent());
        nodes.add(Children.item(13).getTextContent());
        nodes.add("PropertyEnd");
    }
    NodeList.addAll(nodes);
    list.add(NodeList);
}

我想要列表"数组采用这种格式:

I want the "list" array to be in this format:

[[PropertyStart,a,b,c,PropertyEnd],[PropertyStart,d,e,f,PropertyEnd],[PropertyStart,......]]

但是从上面的代码来看，list"数组输出如下所示:

But from the above code, the "list" array output is seen like this:

[PropertyStart,a,b,c,PropertyEnd,PropertyStart,d,e,f,PropertyEnd,PropertyStart,....PropertyEnd]

我想您可能已经注意到了差异.我无法以预期的格式获得结果.

I think you might have noticed the difference. I am not able to achieve the result in expected format.

推荐答案

那么你需要一个ArrayLists的ArrayList:

ArrayList<ArrayList<String>> nodes = new ArrayList<ArrayList<String>>();
ArrayList<String> nodeList = new ArrayList<String>();
nodes.add(nodeList);

请注意，NodeList 已更改为 nodeList.在 Java 命名约定 中，变量以小写开头.类以大写开头.

Note that NodeList has been changed to nodeList. In Java Naming Conventions variables start with a lower case. Classes start with an upper case.

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