xml - 具有不同深度的 xml 文档的 xpath

Question

我有一个 xml 文档，其中有固定的结构，但深度是变化的，例如:-

1. It has main node <project>.
2. it has child node <namespace> that may be repeated multiple times. And there may come some new tags before or after <namespace>.

<project>
 <newtag>
 <namespace>
   <namespace>
     ..........
   </namespace>
 </namespace>
 </newtag>
</project>

3. After multiple namespace there are two more tags of my interest <querySubject> and <queryItem>

我正在使用特定的 XPATH 在 queryItem 标签中搜索文本:-

/project/namespace/namespace/querySubject/queryItem[contains(., 'searchTerm')]/ancestor-or-self::*/name

对于下面给出的特定结构，我的 Xpath 工作正常:-

<project>
<namespace>
        <name locale="en">Test</name>
        <lastChanged>2016-01-12T12:42:46</lastChanged>
            <namespace>
            <name locale="en">Database Layer</name>
                <querySubject status="valid">
                <name locale="en">qskxyz</name>
                    <queryItem>
                    <name locale="en">qixyz</name>
                        <hello>searchTerm</hello>
                    </queryItem>
                </querySubject>
            </namespace>
 </namespace>
 <namespace>
        <name locale="en">Test</name>
        <lastChanged>2016-01-12T12:42:46</lastChanged>
            <namespace>
            <name locale="en">Database Layer</name>
                <querySubject status="valid">
                <name locale="en">qsxyz</name>
                    <queryItem>
                    <name locale="en">myName</name>
                        <hello>...Hi there..</hello>
                    </queryItem>
                </querySubject>
            </namespace>
 </namespace>
 </project>

但如果如上几点所述发生变化，则无法正常工作。任何建议

编辑 1.

我的观察有些失误

我的实际项目标签是

<project containsDynamicContent="false" xmlns="http://www.developer.cognos.com/schemas/bmt/60/7" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.developer.cognos.com/schemas/bmt/60/7 BMTModelSpecification.xsd">

但是在开发中我采用简单的 <project></project>

这影响了我的 Xpath 不工作。我在 Xpath 下尝试过的任何建议但这也不起作用，我无法更改我的 xml 标记。我已经尝试过这个 xpath :-

//namespace//querySubject/queryItem[contains(.,'searchTerm')]/ancestor-or-self::*/name 

Answer 1

基本上，XPath 表达式是:

/x:project//x:namespace//x:querySubject/x:queryItem[contains(.,'searchTerm')]/ancestor-or-self::*/x:name

然后需要关联命名空间http://www.developer.cognos.com/schemas/bmt/60/7带有前缀 x .

---

我将留给您一个 Java (1.7) 代码片段作为示例。这注册了一个 NamespaceContext使用 XPath 表达式，它解析前缀的 namespace (在本例中为 x)。该片段是一个简单的例子，它甚至不检查传递给 NamespaceContext.getNamespaceURI 的前缀。 .典型的实现使用映射将 URI 映射到前缀。

其他开发环境应该具有类似的功能。

---

import java.io.StringReader;
import java.util.Iterator;
import javax.xml.namespace.NamespaceContext;
import javax.xml.xpath.*;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;

public class XPathInXmlns {
    private static final String xml=
"<project containsDynamicContent=\"false\" xmlns=\"http://www.developer.cognos.com/schemas/bmt/60/7\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://www.developer.cognos.com/schemas/bmt/60/7 BMTModelSpecification.xsd\">"+
"   <namespace>"+
"           <name locale=\"en\">Test</name>"+
"           <lastChanged>2016-01-12T12:42:46</lastChanged>"+
"               <namespace>"+
"               <name locale=\"en\">Database Layer</name>"+
"                   <querySubject status=\"valid\">"+
"                   <name locale=\"en\">qskxyz</name>"+
"                       <queryItem>"+
"                       <name locale=\"en\">qixyz</name>"+
"                           <hello>searchTerm</hello>"+
"                       </queryItem>"+
"                   </querySubject>"+
"               </namespace>"+
"    </namespace>"+
"    <namespace>"+
"           <name locale=\"en\">Test</name>"+
"           <lastChanged>2016-01-12T12:42:46</lastChanged>"+
"               <namespace>"+
"               <name locale=\"en\">Database Layer</name>"+
"                   <querySubject status=\"valid\">"+
"                   <name locale=\"en\">qsxyz</name>"+
"                       <queryItem>"+
"                       <name locale=\"en\">myName</name>"+
"                           <hello>...Hi there..</hello>"+
"                       </queryItem>"+
"                   </querySubject>"+
"               </namespace>"+
"    </namespace>"+
" </project>";

    private static final String xpathExpr=
"/x:project//x:namespace//x:querySubject/x:queryItem[contains(.,'searchTerm')]/ancestor-or-self::*/x:name/text()";

    public static void main(String[] args) {
        try {
            XPath xpath = XPathFactory.newInstance().newXPath();
            xpath.setNamespaceContext(new NamespaceContext() {
                @Override
                public Iterator getPrefixes(String namespaceURI) {
                    return null;
                }
                @Override
                public String getPrefix(String namespaceURI) {
                    return null;
                }
                @Override
                public String getNamespaceURI(String prefix) {
                    return "http://www.developer.cognos.com/schemas/bmt/60/7";
                }
            });
            XPathExpression expr = xpath.compile(xpathExpr);
            NodeList nodeList = (NodeList) expr.evaluate(new InputSource(new StringReader(xml)),XPathConstants.NODESET);
            for( int i = 0; i != nodeList.getLength(); ++i )
                System.out.println(nodeList.item(i).getNodeValue());
        } catch (XPathExpressionException e) {
            e.printStackTrace();
        }
    }
}

输出:

Test
Database Layer
qskxyz
qixyz