Xpath仅选择具有空值的属性

Question

如何对此表达式进行格式设置，以便在for循环运行时仅选择分析属性为空的位置。原因是有多个具有相同值的templateNames。这是我的尝试，但不能去上班

String theXpath = "//report-plan[@name='"+ templateName +"']/settings/@analysis=''"; 

示例代码：

public class XPathTestReports { 
    public static void main(String[] args) { 
     try { 
      String outputFile = "c:/workspace/samplenew.xml"; 
      String inputFile = "c:/workspace/sample.xml"; 

      Document doc = DocumentBuilderFactory.newInstance() 
      .newDocumentBuilder().parse(new InputSource(inputFile)); 

      // locate the node(s) 
      XPath xpath = XPathFactory.newInstance().newXPath(); 

      // lOAD THE File 
      CSVImporterReports loader = new CSVImporterReports("C:/REPORT_TEMPLATES.csv"); 
      List <OnConfig> entries = loader.getEntries(); 

      for (OnConfig c: entries) { 
       String templateName = c.getTemplateName(); 
       String analName = c.getAnalysisName(); 
       String paramName = c.getParamName(); 
       String theXpath = "//report-plan[@name='" + templateName + "']/settings/@analysis=''"; 
       NodeList nodes = (NodeList) xpath.evaluate(theXpath, doc, XPathConstants.NODESET); 

       // make the change 
       for (int i = 0; i < nodes.getLength(); i++) { 
        nodes.item(i).setTextContent(analName); 
        // nodes.item(i).setTextContent(paramName); 
       } 
      } 

      try { 
       // save the result 
       Transformer xformer = TransformerFactory.newInstance().newTransformer(); 
       xformer.transform(new DOMSource(doc), new StreamResult(new File(outputFile))); 
      } catch (TransformerConfigurationException e) { 
       // TODO Auto-generated catch block 
      } catch (TransformerFactoryConfigurationError e) { 
       // TODO Auto-generated catch block 
      } catch (TransformerException e) { 
       // TODO Auto-generated catch block 
      } 
     } catch (FileNotFoundException e) { 
      e.printStackTrace(); 
     } catch (SAXException e) { 
      e.printStackTrace(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } catch (ParserConfigurationException e) { 
      e.printStackTrace(); 
     } catch (XPathExpressionException e) { 
      e.printStackTrace(); 
     } 
    } 
} 

示例XML：

<report-plan name="generic"> 
       <columns> 
       <column name="Nominal" subtotal-function="Sum" total-function="Sum"/> 
       <column name="Trade"/> 
       </columns> 
       <settings analysis="" analysisParameters="" filtering-enabled="true" object-actions="false" show-object-actions="true" sorting-enabled="true"/> 
</report-plan> 
<report-plan name="generic"> 
       <columns> 
       <column name="Nominal" subtotal-function="Sum" total-function="Sum"/> 
       <column name="Trade"/> 
       </columns> 
       <settings analysis="" analysisParameters="" filtering-enabled="true" object-actions="false" show-object-actions="true" sorting-enabled="true"/> 
</report-plan> 
<report-plan name="sensitive"> 
       <columns> 
       <column name="Nominal" subtotal-function="Sum" total-function="Sum"/> 
       <column name="Trade"/> 
       </columns> 
       <settings analysis="" analysisParameters="" filtering-enabled="true" object-actions="false" show-object-actions="true" sorting-enabled="true"/> 
</report-plan> 

目前我的代码输入两个相同的值报告命名为通用。即使分析属性具有不同的输入值。即使报告名称相同，我也需要输入不同分析值的代码。

输出：

<report-plan name="generic"> 
       <columns> 
       <column name="Nominal" subtotal-function="Sum" total-function="Sum"/> 
       <column name="Trade"/> 
       </columns> 
       <settings analysis="newValue" analysisParameters="" filtering-enabled="true" object-actions="false" show-object-actions="true" sorting-enabled="true"/> 
</report-plan> 
<report-plan name="generic"> 
       <columns> 
       <column name="Nominal" subtotal-function="Sum" total-function="Sum"/> 
       <column name="Trade"/> 
       </columns> 
       <settings analysis="newValue" analysisParameters="" filtering-enabled="true" object-actions="false" show-object-actions="true" sorting-enabled="true"/> 
</report-plan> 
<report-plan name="sensitive"> 
       <columns> 
       <column name="Nominal" subtotal-function="Sum" total-function="Sum"/> 
       <column name="Trade"/> 
       </columns> 
       <settings analysis="someValue" analysisParameters="" filtering-enabled="true" object-actions="false" show-object-actions="true" sorting-enabled="true"/> 
</report-plan> 

CSV样本

TEMPLATE_NAME ANALYSIS_NAME PARAM_NAME 
generic   analval1  paramval1 
generic   analval2  paramval2 
sensitivity  analval3  paramval3 

Answer 1

好吧，我想我明白你要去的地方。您希望使用XPath为您提供存在并且为空的@analysis节点，以便您可以使用一些配置的值来填充它们。

String theXpath = "//report-plan[@name='" + templateName + "']/settings/@analysis[.='']"; 

编辑补充：

现在，请记住，这将选择所有的模板名称@analysis节点。当您执行第二级for循环时，您将更改所有这些循环。在下一个名为“generic”的CSV上，它将找不到可以更改的节点。

替换：

for (int i = 0; i < nodes.getLength(); i++) { 
    nodes.item(i).setTextContent(analName); 
} 

有：

if (nodes.getLength() > 0) { 
    nodes.item(0).setTextContent(analName); 
} 

Answer 2

也许你的意思是这样

String theXpath = "//report-plan[@name='"+ templateName +"' and not(settings/@analysis > '')]"; 

这将选择所有<report-plan>元素具有一定的名字，没有settings/@analysis（或空一）。