java - 为什么XPATH无法访问该标签的值？ ( java 语)

Question

我是 XPATH 的新手，并且遇到以下问题:

我有以下代码片段，但似乎无法按我的预期工作:

                String XML = cdataContent;

                // Crea un nuovo documento XML a partire dal contenuto della
                // precedente sezione CDATA:
                documentXML = builder.build(new StringReader(XML));

                System.out.println(documentXML.toString());
                System.out.println("CDATA Content in XML document:");
                org.jdom.output.XMLOutputter xmlOutputterCDATAContent = new org.jdom.output.XMLOutputter(
                        org.jdom.output.Format.getPrettyFormat());
                xmlOutputter.output(documentXML, System.out);

                // Crea una nuova query XPATH per selezionare il valore del tag id e lo mette dentro l'oggetto AuthResponse:
                xPath = XPath.newInstance("/root/status/id");
                objectElement = (Element) xPath.selectSingleNode(documentXML);
                System.out.println("Y " + objectElement.getValue() + " Y");
                authResponse.setStatusResponse(objectElement.getValue());

                // Crea una nuova query XPATH per selezionare il valore del tag message: e lo mette dentro l'oggetto AuthResponse:
                XPath xPathMessage = XPath.newInstance("/root/status/message");
                Element objectElementMessage = (Element) xPath.selectSingleNode(documentXML);
                System.out.println("MESSAGE: " + objectElementMessage.getValue() + " /MESSAGE");
                authResponse.setStatusResponse(objectElementMessage.getValue());
            }
        } catch (JDOMException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

这是 documentXML 变量的内容:

<?xml version="1.0" encoding="UTF-8"?>
<root>
  <status>
    <id>-1</id>
    <message>Login o password errate</message>
  </status>
</root>

我通过前面的代码行打印它:

org.jdom.output.XMLOutputter xmlOutputterCDATAContent = new org.jdom.output.XMLOutputter( org.jdom.output.Format.getPrettyFormat());
xmlOutputter.output(documentXML, System.out);

现在我必须创建 2 个 XPATH 查询:第一个必须采用 id 标记的值(在本例中为 -1> value)，第二个必须采用 message 标记内的值(在本例中为字符串值 “Login o password errate”)

好的，正如您在发布的片段中看到的那样，我已经这样做了:

1) 获取 id 标签值的 XPATH 查询:

xPath = XPath.newInstance("/root/status/id");
objectElement = (Element) xPath.selectSingleNode(documentXML);
System.out.println("Y " + objectElement.getValue() + " Y");

这个查询似乎运行良好，因为在 Eclipse 控制台中打印了:

Y -1 Y

(所以我知道-1值是正确的)

2) XPATH 查询以获取消息标记值:

然后我这样做:

XPath xPathMessage = XPath.newInstance("/root/status/message");
Element objectElementMessage = (Element) xPath.selectSingleNode(documentXML);
System.out.println("MESSAGE: " + objectElementMessage.getValue() + " /MESSAGE");

现在发生了一些奇怪的事情，因为在 Eclipse 控制台中，打印以下输出:

消息:-1/消息

而不是MESSAGE:登录o密码错误/MESSAGE如我所料(因为这是消息标签内的值)

为什么？我缺少什么？我该如何解决这种情况？

Tnx

安德里亚

Answer 1

 XPath xPathMessage = XPath.newInstance("/root/status/message");
 Element objectElementMessage = (Element) xPath.selectSingleNode(documentXML);

修改为

XPath xPathMessage = XPath.newInstance("/root/status/message");
Element objectElementMessage = (Element) xPathMessage.selectSingleNode(documentXML);