domoutputter.java

一个用于搜索本地文件内容的小型搜索引擎

            }
            catch (ClassNotFoundException e) {
                // e.printStackTrace();
            }
            catch (IllegalAccessException e) {
                // e.printStackTrace();
            }
            catch (InstantiationException e) {
                // e.printStackTrace();
            }
        }

        // If no DOM doc yet, try to use a hard coded default
        try {
            DOMAdapter adapter = (DOMAdapter)
                Class.forName(DEFAULT_ADAPTER_CLASS).newInstance();
            return adapter.createDocument(dt);
            // System.out.println("Using default " +
            //   DEFAULT_ADAPTER_CLASS);
        }
        catch (ClassNotFoundException e) {
            // e.printStackTrace();
        }
        catch (IllegalAccessException e) {
            // e.printStackTrace();
        }
        catch (InstantiationException e) {
            // e.printStackTrace();
        }

        throw new JDOMException("No JAXP or default parser available");
        
    }

    private org.w3c.dom.Element output(Element element,
                                         org.w3c.dom.Document domDoc,
                                         NamespaceStack namespaces)
                                         throws JDOMException {
        try {
            int previouslyDeclaredNamespaces = namespaces.size();

            org.w3c.dom.Element domElement = null;
            if (element.getNamespace() == Namespace.NO_NAMESPACE) {
                // No namespace, use createElement
                domElement = forceNamespaceAware ?
                             domDoc.createElementNS(null, element.getQualifiedName())
                             : domDoc.createElement(element.getQualifiedName());            }
            else {
                domElement = domDoc.createElementNS(
                                          element.getNamespaceURI(),
                                          element.getQualifiedName());
            }

            // Add namespace attributes, beginning with the element's own
            // Do this only if it's not the XML namespace and it's
            // not the NO_NAMESPACE with the prefix "" not yet mapped
            // (we do output xmlns="" if the "" prefix was already used 
            // and we need to reclaim it for the NO_NAMESPACE)
            Namespace ns = element.getNamespace();
            if (ns != Namespace.XML_NAMESPACE &&
                           !(ns == Namespace.NO_NAMESPACE && 
                             namespaces.getURI("") == null)) {
                String prefix = ns.getPrefix();
                String uri = namespaces.getURI(prefix);
                if (!ns.getURI().equals(uri)) { // output a new namespace decl
                    namespaces.push(ns);
                    String attrName = getXmlnsTagFor(ns);
                    domElement.setAttribute(attrName, ns.getURI());
                }
            }

            // Add additional namespaces also
            Iterator itr = element.getAdditionalNamespaces().iterator();
            while (itr.hasNext()) {
                Namespace additional = (Namespace)itr.next();
                String prefix = additional.getPrefix();
                String uri = namespaces.getURI(prefix);
                if (!additional.getURI().equals(uri)) {
                    String attrName = getXmlnsTagFor(additional);
                    domElement.setAttribute(attrName, additional.getURI());
                    namespaces.push(additional);
                }
            }

            // Add attributes to the DOM element
            itr = element.getAttributes().iterator();
            while (itr.hasNext()) {
                Attribute attribute = (Attribute) itr.next();
                domElement.setAttributeNode(output(attribute, domDoc));
                Namespace ns1 = attribute.getNamespace();
                if ((ns1 != Namespace.NO_NAMESPACE) && 
                    (ns1 != Namespace.XML_NAMESPACE)) {
                    String prefix = ns1.getPrefix();
                    String uri = namespaces.getURI(prefix);
                    if (!ns1.getURI().equals(uri)) { // output a new decl
                        String attrName = getXmlnsTagFor(ns1);
                        domElement.setAttribute(attrName, ns1.getURI());
                        namespaces.push(ns1);
                    }
                }
                // Crimson doesn't like setAttributeNS() for non-NS attribs
                if (attribute.getNamespace() == Namespace.NO_NAMESPACE) {
                    // No namespace, use setAttribute
                    if (forceNamespaceAware) {
                        domElement.setAttributeNS(null,
                                                  attribute.getQualifiedName(),
                                                  attribute.getValue());
                    } else {
                        domElement.setAttribute(attribute.getQualifiedName(),
                                                attribute.getValue());
                    }
                }
                else {
                    domElement.setAttributeNS(attribute.getNamespaceURI(),
                                              attribute.getQualifiedName(),
                                              attribute.getValue());
                }
            }

            // Add content to the DOM element
            itr = element.getContent().iterator();
            while (itr.hasNext()) {
                Object node = itr.next();

                if (node instanceof Element) {
                    Element e = (Element) node;
                    org.w3c.dom.Element domElt = output(e, domDoc, namespaces);
                    domElement.appendChild(domElt);
                }
                else if (node instanceof String) {
                    String str = (String) node;
                    org.w3c.dom.Text domText = domDoc.createTextNode(str);
                    domElement.appendChild(domText);
                }
                else if (node instanceof CDATA) {
                    CDATA cdata = (CDATA) node;
                    org.w3c.dom.CDATASection domCdata =
                        domDoc.createCDATASection(cdata.getText());
                    domElement.appendChild(domCdata);
                }
                else if (node instanceof Text) {
                    Text text = (Text) node;
                    org.w3c.dom.Text domText =
                        domDoc.createTextNode(text.getText());
                    domElement.appendChild(domText);
                }
                else if (node instanceof Comment) {
                    Comment comment = (Comment) node;
                    org.w3c.dom.Comment domComment =
                        domDoc.createComment(comment.getText());
                    domElement.appendChild(domComment);
                }
                else if (node instanceof ProcessingInstruction) {
                    ProcessingInstruction pi = 
                        (ProcessingInstruction) node;
                    org.w3c.dom.ProcessingInstruction domPI =
                         domDoc.createProcessingInstruction(
                         pi.getTarget(), pi.getData());
                    domElement.appendChild(domPI);
                }
                else if (node instanceof EntityRef) {
                    EntityRef entity = (EntityRef) node;
                    org.w3c.dom.EntityReference domEntity =
                        domDoc.createEntityReference(entity.getName());
                    domElement.appendChild(domEntity);
                }
                else {
                    throw new JDOMException(
                        "Element contained content with type:" +
                        node.getClass().getName());
                }
            }
    
            // Remove declared namespaces from stack
            while (namespaces.size() > previouslyDeclaredNamespaces) {
                namespaces.pop();
            }

            return domElement;
        }
        catch (Exception e) {
            throw new JDOMException("Exception outputting Element " +
                                    element.getQualifiedName(), e);
        }
    }

    private org.w3c.dom.Attr output(Attribute attribute,
                                      org.w3c.dom.Document domDoc)
                                      throws JDOMException {
         org.w3c.dom.Attr domAttr = null;
         try {
             if (attribute.getNamespace() == Namespace.NO_NAMESPACE) {
                 // No namespace, use createAttribute
                 if (forceNamespaceAware) {
                     domAttr = domDoc.createAttributeNS(null, attribute.getQualifiedName());
                 } else {
                     domAttr = domDoc.createAttribute(attribute.getQualifiedName());
                 }
             }
             else {
                 domAttr = domDoc.createAttributeNS(attribute.getNamespaceURI(),
                                                  attribute.getQualifiedName());
             }
             domAttr.setValue(attribute.getValue());
         } catch (Exception e) {
             throw new JDOMException("Exception outputting Attribute " +
                                     attribute.getQualifiedName(), e);
         }
         return domAttr;
    }

    /**
     * This will handle adding any <code>{@link Namespace}</code>
     * attributes to the DOM tree.
     *
     * @param ns <code>Namespace</code> to add definition of
     */
    private static String getXmlnsTagFor(Namespace ns) {
        String attrName = "xmlns";
        if (!ns.getPrefix().equals("")) {
            attrName += ":";
            attrName += ns.getPrefix();
        }
        return attrName;
    }
}