問題描述

我想獲取標簽之間的所有內容，但由于 urn: 命名空間，我不知道該怎么做.

I would like to get all the content in between the tags but I do not know how to do this because of the urn: namespace.

<urn:ResponseStatus version="1.0" xmlns:urn="urn:camera-org">

<urn:requestURL>/CAMERA/Streaming/status</urn:requestURL>
<urn:statusCode>4</urn:statusCode>
<urn:statusString>Invalid Operation</urn:statusString>
<urn:id>0</urn:id>

</urn:ResponseStatus>

有什么想法嗎?

推薦答案

1. 簡答:使用 XPath local-name().像這樣: xPathFactory.newXPath().compile("http://*[local-name()='requestURL']/text()"); 將返回 /CAMERA/Streaming/狀態
2. 或者您可以實現一個 NamespaceContext 來映射命名空間名稱和 URI，并在查詢之前將其設置在 XPath 對象上.
3. 看看這篇博客文章，更新:文章已下架，您可以在webarchive

1. Short answer: use XPath local-name(). Like this: xPathFactory.newXPath().compile("http://*[local-name()='requestURL']/text()"); will return /CAMERA/Streaming/status
2. Or you can implement a NamespaceContext that maps namespaces names and URIs and set it on the XPath object before querying.
3. Take a look at this blog article, Update: the article is down, you can see it on webarchive

解決方案 1 示例:

XPath xpath = XPathFactory.newInstance().newXPath();
String responseStatus = xpath.evaluate("http://*[local-name()='ResponseStatus']/text()", document);
System.out.println("-> " + responseStatus);

解決方案 2 示例:

// load the Document
Document document = ...;
NamespaceContext ctx = new NamespaceContext() {
    public String getNamespaceURI(String prefix) {
        return prefix.equals("urn") ? "urn:camera-org" : null; 
    }
    public Iterator getPrefixes(String val) {
        return null;
    }
    public String getPrefix(String uri) {
        return null;
    }
};
XPath xpath = XPathFactory.newInstance().newXPath();
xpath.setNamespaceContext(ctx);
String responseStatus = xpath.evaluate("http://urn:ResponseStatus/text()", document);
System.out.println("-> " + responseStatus);

編輯

這是一個完整的例子，它正確地檢索了元素:

This is a complete example, it correctly retrieve the element:

String xml = "<urn:ResponseStatus version="1.0" xmlns:urn="urn:camera-org">
" + //
        "
" + //
        "<urn:requestURL>/CAMERA/Streaming/status</urn:requestURL>
" + //
        "<urn:statusCode>4</urn:statusCode>
" + //
        "<urn:statusString>Invalid Operation</urn:statusString>
" + //
        "<urn:id>0</urn:id>
" + //
        "
" + //
        "</urn:ResponseStatus>";
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(new java.io.ByteArrayInputStream(xml.getBytes()));
XPath xpath = XPathFactory.newInstance().newXPath();
xpath.setNamespaceContext(new NamespaceContext() {
    public String getNamespaceURI(String prefix) {
        return prefix.equals("urn") ? "urn:camera-org" : null;
    }

    public Iterator<?> getPrefixes(String val) {
        return null;
    }

    public String getPrefix(String uri) {
        return null;
    }
});
XPathExpression expr = xpath.compile("http://urn:ResponseStatus");
Object result = expr.evaluate(doc, XPathConstants.NODESET);
NodeList nodes = (NodeList) result;
for (int i = 0; i < nodes.getLength(); i++) {
    Node currentItem = nodes.item(i);
    System.out.println("found node -> " + currentItem.getLocalName() + " (namespace: " + currentItem.getNamespaceURI() + ")");
}

這篇關于Java中帶有命名空間的XPath的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！