java - 无法从 XML 节点填充 List

Question

我有一个 xml 文档要解析哪些嵌套节点我已经尝试过但无法按要求完成工作。XML文档是

<Items>
   <Item>
   <MediumImage>
      <URL>http://ecx.images-amazon.com/images/I/51l7DDD1qNL._SL160_.jpg</URL>
      <Height Units="pixels">160</Height>
      <Width Units="pixels">160</Width>
   </MediumImage>
   <Title>Fallout 4 Vault Dweller's Survival Guide Collector's Edition: Prima Official Game Guide</Title>
   <OfferSummary>
   <LowestNewPrice>
   <Amount>1952</Amount>
   </OfferSummary>
   </Item>
   .
   .
   .
</Items>

我已将 Title 节点值获取为

private static NodeList fetchTitle(String requestUrl) {
        NodeList nodeList = null;
        try {
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            Document doc = db.parse(requestUrl);
            nodeList = doc.getElementsByTagName("Title");            
        } catch (Exception e) {
            System.out.println("Message is " + e.getCause() + "...." + e.getMessage());
            throw new RuntimeException(e);
        }
        return nodeList;
    }

然后我在 main() 中打印为

titleList = fetchTitle(requestUrl);        
        for (int i = 0; i < titleList.getLength(); i++) {
            Node node = titleList.item(i);
            if (node.getNodeType() == Node.ELEMENT_NODE) {
                // do something with the current element
                System.out.println(node.getNodeName()); 
                System.out.println("Signed Title is \"" + node.getTextContent() + "\"");
                System.out.println();
            }

        }

和 Amount 值来自 LowestNewPrice 节点作为

private static NodeList fetchPrice(String requestUrl) {
        NodeList nodeList = null;
        try {
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            Document doc = db.parse(requestUrl);
            nodeList = doc.getElementsByTagName("LowestNewPrice");           
        } catch (Exception e) {
            System.out.println("Message is " + e.getCause() + "...." + e.getMessage());
            throw new RuntimeException(e);
        }
        return nodeList;
    }

然后我在 main() 中打印为

priceList = fetchPrice(requestUrl);

        for (int i = 0; i < priceList.getLength(); i++) {
            Node node = priceList.item(i).getFirstChild();
            if (node.getNodeType() == Node.ELEMENT_NODE) {
                // do something with the current element
                System.out.println(node.getNodeName()); 
                System.out.println("Signed Price is \"" + node.getTextContent() + "\"");
                System.out.println();
            }

        }

通过上面的代码，我首先获得了所有 Title 值，然后分别获得了 Amount 值，但我真正想要的是拥有一个 POJO 类作为

public class Item {

    String title;
    String price;

    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public String getPrice() {
        return price;
    }
    public void setPrice(String price) {
        this.price = price;
    }

}

并使用 setTitle(), setPrice() 向 Item 对象添加值, 并返回 List<Item>请提供任何帮助。

Answer 1

请您可以尝试此解决方案。解析您的数据并添加到 List<Item>如:

public static Document fetchRequiredData(String src) {
    Document doc = null;

    DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder parser;

    try {
        parser = dbFactory.newDocumentBuilder();
        doc= parser.parse(src);
    } catch (ParserConfigurationException e) {
        e.printStackTrace();
    } catch (SAXException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    return doc;
}

public static List<Item>  parseItemInfo(Document doc){

    List<Item> items = new ArrayList<Item>();
    NodeList itemNodeList = doc.getElementsByTagName("Item");       

    for (int i = 0; i < itemNodeList.getLength(); i++) {

        Node titleNode = doc.getElementsByTagName("Title").item(i);
        Node priceNode = doc.getElementsByTagName("LowestNewPrice").item(i).getFirstChild();

        if (titleNode.getNodeType() == Node.ELEMENT_NODE || priceNode.getNodeType() == Node.ELEMENT_NODE ) {
            Item item = new Item();
            item.setDesc(titleNode.getTextContent());
            item.setPrice(priceNode.getTextContent());
            items.add(item);
        }
    }
    return items;
}

现在您的列表已准备好在 main() 中进行测试方法如

public static void main(String[] args) {
     List<Item> items = parseItemInfo(fetchRequiredData(requestUrl));
     System.out.println("Printing List<Item> contents ...");
     for (Item item : items) {
         System.out.println("Title is " + item.getTitle()); 
         System.out.println("Price is " + item.getPrice());
         System.out.println();
     }
}

希望这对您有所帮助。