xml元素中的重複檢查

Question

我需要使用xml元素屬性值進行重複檢查。

樣品輸入請求：

<Parent> 
    <child id="1"> test 1</child> 
    <child id="1"> test 2</child> 
    <child id="2"> test 3</child> 
</parent> 

我想找到ID重複使用XSD或其他方式將fine.Anyone請幫我檢測到重複元件，它存在於請求XML子元素屬性屬性值。

Answer 1

基本上，您需要使用xsd:unique來強制執行元素或屬性的唯一性。下面是從鏈路的摘錄：

指定屬性或元素值（或 屬性或元素值的組合）必須在規定的 範圍內是唯一的。該值必須是唯一的或零。

在情況下，如果你不知道，那麼你需要使用它，你可以強制執行這種唯一性，然後驗證您不要使用任何可用的XML解析器是XSD/DTD XML創建XSD/DTD。下面是一個Java示例以及XSD。

您的問題聲明：

請求XML使用XSD或其他方式將被罰款

按我所知，如果你想查詢你的XML文檔的有效性，然後您必須有XSD或DTD，沒有其他方式可以在沒有XSD或DTD（或更少了解RELAX NG）的情況下執行此操作。因此，您只需編寫一個定義XML文檔的預期結構的XSD或DTD，然後使用一些XML驗證程序來根據該XSD/DTD驗證您的XML文檔，它會告訴您XML文檔是否符合XSD/DTD與否。 底線是您需要編寫/指定一個XSD/DTD，它定義了XML文檔的預期結構。

你的XML： 「so.xml」

<Parent> 
    <child id="1"> test 1</child> 
    <child id="2"> test 2</child> 
    <child id="2"> test 3</child> 
</Parent> 

樣品XSD你需要（與XSD：獨特的您的要求）： 「so.xsd」

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified"> 
    <xs:element name="Parent"> 
     <xs:complexType> 
      <xs:sequence> 
       <xs:element name="child" maxOccurs="unbounded"> 
        <xs:complexType> 
         <xs:simpleContent> 
          <xs:extension base="xs:string"> 
           <xs:attribute name="id" type="xs:token" use="required"/> 
          </xs:extension> 
         </xs:simpleContent> 
        </xs:complexType> 
       </xs:element> 
      </xs:sequence> 
     </xs:complexType> 
    <!-- This is the solution of your problem - "xs:unique" --> 
    <xs:unique name="unique-id"> 
      <xs:selector xpath="child"/> 
      <xs:field xpath="@id"/> 
     </xs:unique> 
    </xs:element> 
</xs:schema> 

用於驗證的Java代碼示例：

import org.w3c.dom.Document; 
import org.xml.sax.SAXException; 
import org.xml.sax.SAXParseException; 
import org.xml.sax.InputSource; 


import java.io.File; 
import java.io.FileNotFoundException; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.StringReader; 


import javax.xml.XMLConstants; 
import javax.xml.parsers.DocumentBuilder; 
import javax.xml.parsers.DocumentBuilderFactory; 
import javax.xml.parsers.ParserConfigurationException; 
import javax.xml.transform.Source; 

import javax.xml.transform.dom.DOMSource; 
import javax.xml.transform.stream.StreamSource; 
import javax.xml.validation.Schema; 
import javax.xml.validation.SchemaFactory; 
import javax.xml.validation.Validator; 

public class XmlSchemaValidationHelper { 

    public static void main(String[] argv) { 
     XmlSchemaValidationHelper schemaValidationHelper = new XmlSchemaValidationHelper(); 
     schemaValidationHelper.validateAgainstSchema(new File(argv[0]), new File(argv[1])); 
    } 

    public void validateAgainstSchema(File xmlFile, File xsdFile) { 
     try { 
      System.out.println("### Starting..."); 
      // parse an XML document into a DOM tree 
      DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance(); 
      builderFactory.setNamespaceAware(true); 
      DocumentBuilder parser = builderFactory.newDocumentBuilder(); 
      Document document = parser.parse(xmlFile); 

      // create a SchemaFactory capable of understanding WXS schemas 
      SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI); 

      // load a WXS schema, represented by a Schema instance 
      Source schemaFile = new StreamSource(xsdFile); 
      Schema schema = factory.newSchema(schemaFile); 

      // create a Validator instance, which can be used to validate an 
      // instance document 
      Validator validator = schema.newValidator(); 

      // validate the DOM tree 
      validator.validate(new DOMSource(document)); 
      System.out.println("### Finished..."); 

     } catch (FileNotFoundException ex) { 
      throw new OpenClinicaSystemException("File was not found", ex.getCause()); 
     } catch (IOException ioe) { 
      throw new OpenClinicaSystemException("IO Exception", ioe.getCause()); 
     } catch (SAXParseException spe) { 
      spe.printStackTrace(); 
      throw new OpenClinicaSystemException("Line : " + spe.getLineNumber() + " - " + spe.getMessage(), spe.getCause()); 
     } catch (SAXException e) { 
      throw new OpenClinicaSystemException(e.getMessage(), e.getCause()); 
     } catch (ParserConfigurationException pce) { 
      throw new OpenClinicaSystemException(pce.getMessage(), pce.getCause()); 
     } 
    } 

    public class OpenClinicaSystemException extends RuntimeException { 
     /** 
     * 
     */ 
     private static final long serialVersionUID = 1L; 
     private String errorCode; 
     private Object[] errorParams; 

     public OpenClinicaSystemException(String code, String message) { 
      this(message); 
      this.errorCode = code; 
     } 

     public OpenClinicaSystemException(String code, String message, Throwable cause) { 
      this(message, cause); 
      this.errorCode = code; 
     } 

     public OpenClinicaSystemException(String message, Throwable cause) { 
      super(message, cause); 
     } 

     public OpenClinicaSystemException(Throwable cause) { 
      super(cause); 
     } 

     public OpenClinicaSystemException(String message) { 
      super(message); 
      this.errorCode = message; 
     } 

     public OpenClinicaSystemException(String code, Object[] errorParams) { 
      this.errorCode = code; 
      this.errorParams = errorParams; 
     } 

     public OpenClinicaSystemException(String code, Object[] errorParams, String message) { 
      this(message); 
      this.errorCode = code; 
      this.errorParams = errorParams; 
     } 

     public String getErrorCode() { 
      return errorCode; 
     } 

     public Object[] getErrorParams() { 
      return errorParams; 
     } 

     public void setErrorParams(Object[] errorParams) { 
      this.errorParams = errorParams; 
     } 
    } 

} 

您可以運行此程序爲 - java XmlSchemaValidationHelper so.xml so.xsd