domecho05.java

《j2ee经典实例详解》的源代码。原书无附带光盘。介绍的是一个在线银行系统的例子。绝对难得

                if (x >= 0) {
                    t = t.substring(0, x);
                }

                s += (" " + t);

                return s;
            }

            if (domNode.getNodeValue() != null) {
                if (s.startsWith("ProcInstr")) {
                    s += ", ";
                } else {
                    s += ": ";
                }

                // Trim the value to get rid of NL's at the front
                String t = domNode.getNodeValue()
                                  .trim();
                int x = t.indexOf("\n");

                if (x >= 0) {
                    t = t.substring(0, x);
                }

                s += t;
            }

            return s;
        }

        public String content() {
            String s = "";
            org.w3c.dom.NodeList nodeList = domNode.getChildNodes();

            for (int i = 0; i < nodeList.getLength(); i++) {
                org.w3c.dom.Node node = nodeList.item(i);
                int type = node.getNodeType();
                AdapterNode adpNode = new AdapterNode(node); //inefficient, but works

                if (type == ELEMENT_TYPE) {
                    // Skip subelements that are displayed in the tree.   
                    if (treeElement(node.getNodeName())) {
                        continue;
                    }

                    // EXTRA-CREDIT HOMEWORK:
                    //   Special case the SLIDE element to use the TITLE text
                    //   and ignore TITLE element when constructing the tree.
                    // EXTRA-CREDIT
                    //   Convert ITEM elements to html lists using
                    //   <ul>, <li>, </ul> tags
                    s += ("<" + node.getNodeName() + ">");
                    s += adpNode.content();
                    s += ("</" + node.getNodeName() + ">");
                } else if (type == TEXT_TYPE) {
                    s += node.getNodeValue();
                } else if (type == ENTITYREF_TYPE) {
                    // The content is in the TEXT node under it
                    s += adpNode.content();
                } else if (type == CDATA_TYPE) {
                    // The "value" has the text, same as a text node.
                    //   while EntityRef has it in a text node underneath.
                    //   (because EntityRef can contain multiple subelements)
                    // Convert angle brackets and ampersands for display
                    StringBuffer sb = new StringBuffer(node.getNodeValue());

                    for (int j = 0; j < sb.length(); j++) {
                        if (sb.charAt(j) == '<') {
                            sb.setCharAt(j, '&');
                            sb.insert(j + 1, "lt;");
                            j += 3;
                        } else if (sb.charAt(j) == '&') {
                            sb.setCharAt(j, '&');
                            sb.insert(j + 1, "amp;");
                            j += 4;
                        }
                    }

                    s += ("<pre>" + sb + "\n</pre>");
                }

                // Ignoring these:
                //   ATTR_TYPE      -- not in the DOM tree
                //   ENTITY_TYPE    -- does not appear in the DOM
                //   PROCINSTR_TYPE -- not "data"
                //   COMMENT_TYPE   -- not "data"
                //   DOCUMENT_TYPE  -- Root node only. No data to display.
                //   DOCTYPE_TYPE   -- Appears under the root only
                //   DOCFRAG_TYPE   -- equiv. to "document" for fragments
                //   NOTATION_TYPE  -- nothing but binary data in here
            }

            return s;
        }

        /*
         * Return children, index, and count values
         */
        public int index(AdapterNode child) {
            //System.err.println("Looking for index of " + child);
            int count = childCount();

            for (int i = 0; i < count; i++) {
                AdapterNode n = this.child(i);

                if (child.domNode == n.domNode) {
                    return i;
                }
            }

            return -1; // Should never get here.
        }

        public AdapterNode child(int searchIndex) {
            //Note: JTree index is zero-based. 
            org.w3c.dom.Node node = domNode.getChildNodes()
                                           .item(searchIndex);

            if (compress) {
                // Return Nth displayable node
                int elementNodeIndex = 0;

                for (int i = 0; i < domNode.getChildNodes()
                                               .getLength(); i++) {
                    node = domNode.getChildNodes()
                                  .item(i);

                    if ((node.getNodeType() == ELEMENT_TYPE) &&
                            treeElement(node.getNodeName()) &&
                            (elementNodeIndex++ == searchIndex)) {
                        break;
                    }
                }
            }

            return new AdapterNode(node);
        }

        public int childCount() {
            if (!compress) {
                // Indent this
                return domNode.getChildNodes()
                              .getLength();
            }

            int count = 0;

            for (int i = 0; i < domNode.getChildNodes()
                                           .getLength(); i++) {
                org.w3c.dom.Node node = domNode.getChildNodes()
                                               .item(i);

                if ((node.getNodeType() == ELEMENT_TYPE) &&
                        treeElement(node.getNodeName())) {
                    ++count;
                }
            }

            return count;
        }
    }

    // This adapter converts the current Document (a DOM) into 
    // a JTree model. 
    public class DomToTreeModelAdapter implements javax.swing.tree.TreeModel {
        /*
         * Use these methods to add and remove event listeners.
         * (Needed to satisfy TreeModel interface, but not used.)
         */
        private Vector listenerList = new Vector();

        // Basic TreeModel operations
        public Object getRoot() {
            //System.err.println("Returning root: " +document);
            return new AdapterNode(document);
        }

        public boolean isLeaf(Object aNode) {
            // Determines whether the icon shows up to the left.
            // Return true for any node with no children
            AdapterNode node = (AdapterNode) aNode;

            if (node.childCount() > 0) {
                return false;
            }

            return true;
        }

        public int getChildCount(Object parent) {
            AdapterNode node = (AdapterNode) parent;

            return node.childCount();
        }

        public Object getChild(Object parent, int index) {
            AdapterNode node = (AdapterNode) parent;

            return node.child(index);
        }

        public int getIndexOfChild(Object parent, Object child) {
            AdapterNode node = (AdapterNode) parent;

            return node.index((AdapterNode) child);
        }

        public void valueForPathChanged(TreePath path, Object newValue) {
            // Null. We won't be making changes in the GUI
            // If we did, we would ensure the new value was really new,
            // adjust the model, and then fire a TreeNodesChanged event.
        }

        public void addTreeModelListener(TreeModelListener listener) {
            if ((listener != null) && !listenerList.contains(listener)) {
                listenerList.addElement(listener);
            }
        }

        public void removeTreeModelListener(TreeModelListener listener) {
            if (listener != null) {
                listenerList.removeElement(listener);
            }
        }

        // Note: Since XML works with 1.1, this example uses Vector.
        // If coding for 1.2 or later, though, I'd use this instead:
        //   private List listenerList = new LinkedList();
        // The operations on the List are then add(), remove() and
        // iteration, via:
        //  Iterator it = listenerList.iterator();
        //  while ( it.hasNext() ) {
        //    TreeModelListener listener = (TreeModelListener) it.next();
        //    ...
        //  }

        /*
         * Invoke these methods to inform listeners of changes.
         * (Not needed for this example.)
         * Methods taken from TreeModelSupport class described at
         *   http://java.sun.com/products/jfc/tsc/articles/jtree/index.html
         * That architecture (produced by Tom Santos and Steve Wilson)
         * is more elegant. I just hacked 'em in here so they are
         * immediately at hand.
         */
        public void fireTreeNodesChanged(TreeModelEvent e) {
            Enumeration listeners = listenerList.elements();

            while (listeners.hasMoreElements()) {
                TreeModelListener listener =
                    (TreeModelListener) listeners.nextElement();
                listener.treeNodesChanged(e);
            }
        }

        public void fireTreeNodesInserted(TreeModelEvent e) {
            Enumeration listeners = listenerList.elements();

            while (listeners.hasMoreElements()) {
                TreeModelListener listener =
                    (TreeModelListener) listeners.nextElement();
                listener.treeNodesInserted(e);
            }
        }

        public void fireTreeNodesRemoved(TreeModelEvent e) {
            Enumeration listeners = listenerList.elements();

            while (listeners.hasMoreElements()) {
                TreeModelListener listener =
                    (TreeModelListener) listeners.nextElement();
                listener.treeNodesRemoved(e);
            }
        }

        public void fireTreeStructureChanged(TreeModelEvent e) {
            Enumeration listeners = listenerList.elements();

            while (listeners.hasMoreElements()) {
                TreeModelListener listener =
                    (TreeModelListener) listeners.nextElement();
                listener.treeStructureChanged(e);
            }
        }
    }
}