在 Arraylist<string,List<String>> 中添加值在哈希图 android 中 [英] add the value in Arraylist&lt;string,List&lt;String&gt;&gt; in hashmap android

问题描述

我必须获取数据列表.

所以我使用了带有列表的字符串数组列表.这里我如何在地图上添加值.

So i have used the arraylist of string with list.here how can i add the value on map.

我使用了以下代码:

       static final String KEY_TITLE = "Category";
         static final String KEY_ARTICLE = "article";
          static final String KEY_IMAGE = "image";


 final ArrayList<HashMap<String,  List<String>>> songsList = new ArrayList<HashMap<String,  List<String>>>();
        XMLParser parser = new XMLParser();
        String xml = parser.getXmlFromUrl(URL); // getting XML from URL
        Document doc = parser.getDomElement(xml); // getting DOM element

        NodeList nl = doc.getElementsByTagName(KEY_TITLE);
        NodeList nl1 = doc.getElementsByTagName(KEY_ARTICLE);
        NodeList nl2 = doc.getElementsByTagName(KEY_IMAGE);
        System.out.println(nl.getLength());
        for (int i = 0; i < nl.getLength(); i++) {
           //System.out.println(nl.getLength());
            HashMap<String, List<String>> map = new HashMap<String, List<String>>();
            map.put( KEY_TITLE,((Element)nl.item(i)).getAttribute("name"));
           for (int j = 0; j < nl1.getLength(); j++) {
              map.put( KEY_ARTICLE,((Element)nl1.item(j)).getAttribute("title"));
              map.put( KEY_IMAGE,((Element)nl2.item(j)).getAttribute("url"));
             }
           songsList.add(map);
          }

在这些 (map.put(KEY_TITLE,((Element)nl.item(i)).getAttribute("name"));) 行上出现以下错误:

Here am getting the below error on these (map.put( KEY_TITLE,((Element)nl.item(i)).getAttribute("name"));) line:

The method put(String, List<String>) in the type HashMap<String,List<String>> is not applicable for the arguments (String, String)

我如何清除这些错误..请为我提供解决方案...

How can i clear these error ..pls provide me solution for these ...

推荐答案

在这一行

 map.put( KEY_TITLE,((Element)nl.item(i)).getAttribute("name"));

您要添加单个字符串而不是列表

you are adding a single string to instead of List

您必须在那时创建一个字符串列表，并将您的字符串添加到其中，并将列表添加到您的地图中.

You have to create a List of String at that point and add your String to it and at the list to your map.

例如:

  List<String> myList= new ArrayList<String>();
  myList.add((Element)nl.item(i)).getAttribute("name"));
  map.put( KEY_TITLE,myList);

你有一个循环.我想我知道你想要实现我会更新我的代码.这可以帮助您避免覆盖地图输入

you have a loop. I think that i know what you want to achieve i'll update my code. This can help you avoiding overriding the map input

HashMap<String, List<String>> map = new HashMap<String, List<String>>();

        for(int i = 0; i < nl.getLength(); i++) {
             String name = (Element) nl.item(i)).getAttribute("name");
             populateMap(map, name, KEY_TITLE);
            for(int j = 0; j < nl1.getLength(); j++) {
                String title=(Element) nl1.item(j)).getAttribute("title");
                populateMap(map, title, KEY_ARTICLE);

                String url=(Element) nl2.item(j)).getAttribute("url");
                populateMap(map, url, KEY_IMAGE);
            }
            songsList.add(map);
        }

方法 populateMap()

Method populateMap()

void populateMap(HashMap<String, List<String>> map, String value, String key) {
        List<String> myList;
        if(!map.containsKey(key)) {
            myList = new ArrayList<String>();
            myList.add(value);
            map.put(key, myList);
        } else {
            myList = map.get(key);
            myList.add(value);
        }
    }

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