XSModel：获取模型组信息答案

【问题标题】：XSModel: getting model group informationXSModel：获取模型组信息
【发布时间】：2013-11-02 19:26:52
【问题描述】：

使用 Xerces SAX 库的 XSModel 作为 XSD 语法的表示，如果我有一个引用模型组的复杂类型，我如何检索模型组？似乎由 Xerces 提供的 XSModel 实例表示的复杂类型定义仅提供对组的扁平（扩展）内容（例如组的元素）的访问，而不是实际组或对组定义（甚至是组的名称；XSModelGroupImpl 的getName() 方法由return null 组成......）。

【问题讨论】：

标签： xml xsd xerces

【解决方案1】：

Xerces 很好地展示了模型组。但是，您应该使用org.apache.xerces.xs 包。模型组位于顶级声明中，并作为复杂类型中的粒子。

这是一个示例 Java 代码：

import org.apache.xerces.xs.*;
import org.apache.xerces.dom.DOMXSImplementationSourceImpl;
....

/**
 * Load an XSD file
 */
void loadSchema (String xsdURI)
{
  XSImplementation impl = (XSImplementation)
    (new DOMXSImplementationSourceImpl()).getDOMImplementation ("XS-Loader");

  XSLoader schemaLoader = impl.createXSLoader (null);

  XSModel xsModel = schemaLoader.loadURI (xsdURI);
}

/**
 * Process schema content
 */
private void processXSModel (XSModel xsModel)
{
  XSNamedMap xsMap;

  // process model group definitions
  xsMap = xsModel.getComponents (XSConstants.MODEL_GROUP_DEFINITION);
  for (int i = 0; i < xsMap.getLength(); i ++)
  {
    XSModelGroupDefinition xsGroupDef = (XSModelGroupDefinition) xsMap.item (i);
    XSModelGroup xsGroup = xsGroupDef.getModelGroup();
    ...
  }

  // process top-level type definitions
  xsMap = xsModel.getComponents (XSConstants.TYPE_DEFINITION);
  for (int i = 0; i < xsMap.getLength(); i ++)
  {
    XSTypeDefinition xsTDef = (XSTypeDefinition) xsMap.item (i);
    processXSTypeDef (xsTDef);
  }

  // process top-level element declarations
  xsMap = xsModel.getComponents (XSConstants.ELEMENT_DECLARATION);
  for (int i = 0; i < xsMap.getLength(); i ++)
  {
    XSElementDeclaration xsElementDecl = (XSElementDeclaration) xsMap.item (i);
    processXSElementDecl (xsElementDecl);
  }
}

/**
 * Process type definition
 */
private void processXSTypeDef (XSTypeDefinition xsTDef)
{
  switch (xsTDef.getTypeCategory())
  {
    case XSTypeDefinition.SIMPLE_TYPE:

      processXSSimpleType ((XSSimpleTypeDefinition) xsTDef);
      break;

    case XSTypeDefinition.COMPLEX_TYPE:

      XSComplexTypeDefinition xsCTDef = (XSComplexTypeDefinition) xsTDef;

      // element's attributes
      XSObjectList xsAttrList = xsCTDef.getAttributeUses();
      for (int i = 0; i < xsAttrList.getLength(); i ++)
      {
        processXSAttributeUse ((XSAttributeUse) xsAttrList.item (i));
      }

      // element content
      switch (xsCTDef.getContentType())
      {
        case XSComplexTypeDefinition.CONTENTTYPE_EMPTY:

          break;

        case XSComplexTypeDefinition.CONTENTTYPE_SIMPLE:

          parseValueType (xsCTDef.getSimpleType());
          break;

        case XSComplexTypeDefinition.CONTENTTYPE_ELEMENT:

          processXSParticle (xsCTDef.getParticle());
          break;

        case XSComplexTypeDefinition.CONTENTTYPE_MIXED:

          ...
          processXSParticle (xsCTDef.getParticle());
          break;
        }
      }

      break;
  }

  /**
   * Process particle
  */
  private void processXSParticle (XSParticle xsParticle)
  {
    XSTerm xsTerm = xsParticle.getTerm();
    switch (xsTerm.getType())
    {
      case XSConstants.ELEMENT_DECLARATION:

        processXSElementDecl ((XSElementDeclaration) xsTerm);
        break;

      case XSConstants.MODEL_GROUP:

        // this is one of the globally defined groups 
        // (found in top-level declarations)

        XSModelGroup xsGroup = (XSModelGroup) xsTerm;

        // it also consists of particles
        XSObjectList xsParticleList = xsGroup.getParticles();
        for (int i = 0; i < xsParticleList.getLength(); i ++)
        {
          processXSParticle ((XSParticle) xsParticleList.item (i));
        }

        ...
        break;

      case XSConstants.WILDCARD:

        ...
        break;
    }
  }

【讨论】：