java - 解析 Facebook 的 XML 查询响应问题

Question

嘿伙计们! :) 我正在开发一项服务，可以从 Facebook API 捕获点赞数、分享数等。 但是有一个问题，因为我从 fqlResponse.getChild() 得到一个空指针异常。

我认为自动检测xmls doctype有问题，所以我手动定义了doctype，但问题仍然存在。也许 facebooks xml 文档类型不正确？ 捕获方法如下:

public void refreshLikesSharesClicksAndTotal() throws JDOMException, IOException {
    URL fqlURL = new URL("https://api.facebook.com/method/fql.query?query=select  like_count,    total_count, share_count, click_count from link_stat where url=\"" + this.url.toString() + "\"");
    Document inputXML = new SAXBuilder().build(fqlURL);
    DocType docType = new DocType("xml", "http://www.w3.org/2001/XMLSchema-instance");
    inputXML.setDocType(docType);
    Element fqlResponse = inputXML.getRootElement().getChild("link_stat");
    Element likes = fqlResponse.getChild("like_count");
    logger.info("Likes: " + likes.getText());
    Element shares = fqlResponse.getChild("share_count");
    Element clicks = fqlResponse.getChild("click_count");
    Element total = fqlResponse.getChild("total_count");

    this.likes = Integer.parseInt(likes.getText());
    this.shares = Integer.parseInt(shares.getText());
    this.clicks = Integer.parseInt(clicks.getText());
    this.total = Integer.parseInt(total.getText());

}

XML 示例: https://api.facebook.com/method/fql.query?query=select%20%20like_count,%20total_count,%20share_count,%20click_count%20from%20link_stat%20where%20url=%22http://heise.de%22

德语问题描述: http://www.java-forum.org/xml-co/118648-problem-beim-parsen-facebook-xml.html

感谢您的帮助! 白色内克斯

Answer 1

你可以这样做:-

    URL url = new URL("https://api.facebook.com/method/fql.query?query=select%20like_count,%20total_count,%20share_count,%20click_count%20from%20link_stat%20where%20url=%22http://heise.de%22");

    DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
    domFactory.setNamespaceAware(true);
    Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(url.openStream());
    XPath xPath = XPathFactory.newInstance().newXPath();

    int likeCount = Integer.parseInt(xPath.evaluate("//like_count/text()", doc));
    int totalCount = Integer.parseInt(xPath.evaluate("//total_count/text()", doc));
    int shareCount = Integer.parseInt(xPath.evaluate("//share_count/text()", doc));
    int clickCount = Integer.parseInt(xPath.evaluate("//click_count/text()", doc));

确保使用 %20 和 %22 对 URL 中的空格和双引号进行适当编码。我已经测试过这段代码，它对我有用。