I have tried all possible answers https://stackoverflow.com/questions/33098082/passing-xml-string-as-document-returning-null on Stackoverflow but I can't get this resolved.
我有以下 xml 作为字符串:
private static final String xmlStr = "<parameters>\n" +
" <parameter>\n" +
" <name>emp</name>\n" +
" <keyvalue>John Smith</keyvalue>\n" +
" </parameter>\n" +
" <parameter>\n" +
" <name>age</name>\n" +
" <keyvalue>22</keyvalue>\n" +
" </parameter>\n" +
" <parameter>\n" +
" <name>Birth Date</name>\n" +
" <keyvalue>02/05/1978</keyvalue>\n" +
" </parameter>\n" +
" <parameter>\n" +
" <name>password</name>\n" +
" <keyvalue>ye63633</keyvalue>\n" +
" </parameter>\n" +
"</parameters>";
参数可以替换为任何字符串(我尝试过但没有成功),以下代码返回空文档:
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.parse(new ByteArrayInputStream(xmlStr.getBytes("UTF-8")));
我尝试用以下内容替换文档:
Document document = builder.parse(new InputSource(new StringReader(xmlStr)));//This used to work 2 weeks ago.
document一直返回空文档,我不知道我做错了什么。几周前,同样的代码还可以工作。
我正在使用Java 1.8!
我感谢您的帮助。
UPDATE:
这是采用上述内容的完整代码xmlStr并尝试访问员工的年龄。
private String getElementValue(String tagName, String xmlString) {
try {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.parse(new InputSource(new StringReader(xmlString)));
Element rootElement = document.getDocumentElement();
NodeList list = rootElement.getElementsByTagName(tagName);
if (list != null && list.getLength() > 0) {
NodeList subList = list.item(0).getChildNodes();
if (subList != null && subList.getLength() > 0) {
return subList.item(0).getNodeValue();
}
}
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
根据评论,该文档根本不为空,但访问所需的 xml 标记时出现问题。所以代码NodeList list = rootElement.getElementsByTagName("age");
大小为 0。即它根本不进入循环。