import com.sun.org.apache.xerces.internal.impl.xs.util.XSInputSource; //导入依赖的package包/类
private Element resolveSchema(XMLInputSource schemaSource, XSDDescription desc,
        boolean mustResolve, Element referElement) {

    if (schemaSource instanceof DOMInputSource) {
        return getSchemaDocument(desc.getTargetNamespace(), (DOMInputSource) schemaSource, mustResolve, desc.getContextType(), referElement);
    } // DOMInputSource
    else if (schemaSource instanceof SAXInputSource) {
        return getSchemaDocument(desc.getTargetNamespace(), (SAXInputSource) schemaSource, mustResolve, desc.getContextType(), referElement);
    } // SAXInputSource
    else if (schemaSource instanceof StAXInputSource) {
        return getSchemaDocument(desc.getTargetNamespace(), (StAXInputSource) schemaSource, mustResolve, desc.getContextType(), referElement);
    } // StAXInputSource
    else if (schemaSource instanceof XSInputSource) {
        return getSchemaDocument((XSInputSource) schemaSource, desc);
    } // XSInputSource
    return getSchemaDocument(desc.getTargetNamespace(), schemaSource, mustResolve, desc.getContextType(), referElement);
}
 

import com.sun.org.apache.xerces.internal.impl.xs.util.XSInputSource; //导入依赖的package包/类
/**
 * getSchemaDocument method uses XMLInputSource to parse a schema document.
 * @param schemaNamespace
 * @param schemaSource
 * @param mustResolve
 * @param referType
 * @param referElement
 * @return A schema Element.
 */
private Element getSchemaDocument(XSInputSource schemaSource, XSDDescription desc) {

    SchemaGrammar[] grammars = schemaSource.getGrammars();
    short referType = desc.getContextType();

    if (grammars != null && grammars.length > 0) {
        Vector expandedGrammars = expandGrammars(grammars);
        // check for existing grammars in our bucket
        // and if there exist any, and namespace growth is
        // not enabled - we do nothing
        if (fNamespaceGrowth || !existingGrammars(expandedGrammars)) {
            addGrammars(expandedGrammars);
            if (referType == XSDDescription.CONTEXT_PREPARSE) {
                desc.setTargetNamespace(grammars[0].getTargetNamespace());
            }
        }
    }
    else {
        XSObject[] components = schemaSource.getComponents();
        if (components != null && components.length > 0) {
            Map<String, Vector> importDependencies = new HashMap();
            Vector expandedComponents = expandComponents(components, importDependencies);
            if (fNamespaceGrowth || canAddComponents(expandedComponents)) {
                addGlobalComponents(expandedComponents, importDependencies);
                if (referType == XSDDescription.CONTEXT_PREPARSE) {
                    desc.setTargetNamespace(components[0].getNamespace());
                }
            }
        }
    }
    return null;
}