Dùng DOM đọc file XML biểu biễn trên JTree

Chương trình java sau đây ứng dụng mô hình DOM để duyệt qua 1 văn bản XML sau đó hiển thị lên JTree.

package dom.swing; import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.util.ArrayList; import javax.swing.JFileChooser; import javax.swing.JFrame; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem; import javax.swing.JScrollPane; import javax.swing.JSplitPane; import javax.swing.JTextArea; import javax.swing.JTree; import javax.swing.event.TreeSelectionEvent; import javax.swing.event.TreeSelectionListener; import javax.swing.tree.DefaultMutableTreeNode; import javax.swing.tree.DefaultTreeModel; import org.apache.xerces.parsers.DOMParser; import org.w3c.dom.Attr; import org.w3c.dom.Document; import org.w3c.dom.Node; import org.w3c.dom.NodeList; public class ParseTree extends JFrame implements TreeSelectionListener, ActionListener{ private static final long serialVersionUID = 1L; private DefaultMutableTreeNode root; private DefaultTreeModel model; private JTree tree; private JTextArea taContent; private JMenuBar menubar; private JMenu menuFile; private JMenuItem itemOpen,itemExit; public ParseTree(){ super(“Parser Tree”); setDefaultCloseOperation(EXIT_ON_CLOSE); setSize(700,500); menubar=new JMenuBar(); menuFile=new JMenu(“File”); itemOpen=new JMenuItem(“Open”);itemExit=new JMenuItem(“Exit”); this.setJMenuBar(menubar); menubar.add(menuFile); menuFile.add(itemOpen);menuFile.addSeparator(); menuFile.add(itemExit); itemOpen.addActionListener(this); itemExit.addActionListener(this); root=new DefaultMutableTreeNode(“XML Document”); model=new DefaultTreeModel(root); tree=new JTree(model); tree.addTreeSelectionListener(this); taContent=new JTextArea(); taContent.setEditable(false); JScrollPane xxx=new JScrollPane(taContent); JScrollPane sp=new JScrollPane(tree); sp.setPreferredSize(new Dimension(300,300)); JSplitPane spl=new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,sp,xxx); this.add(spl,BorderLayout.CENTER); } void buildtree(String uri){ try { DOMParser parser=new DOMParser(); parser.parse(uri); Document doc=parser.getDocument(); addNode(doc,root); } catch (Exception e) { e.printStackTrace(); } } void addNode(Node xmlNode,DefaultMutableTreeNode treeNode){ if(xmlNode==null) return; int type=xmlNode.getNodeType(); MyNode mn=null; switch (type) { case Node.DOCUMENT_NODE:{ mn=new MyNode(“xml”,“<?xml version=\”1.0\” encoding =\”UTF-8\”?>”,null); DefaultMutableTreeNode tn=new DefaultMutableTreeNode(mn); root.add(tn); addNode(((Document)xmlNode).getDocumentElement(), treeNode); break; } case Node.ELEMENT_NODE:{ mn=new MyNode(xmlNode.getNodeName(),xmlNode.getNodeValue(),null); int length=(xmlNode.getAttributes()!=null)?xmlNode.getAttributes().getLength():0; ArrayList<String>al=new ArrayList<String>(); Attr []attributes=new Attr[length]; for (int i = 0; i < length; i++) { attributes[i]=(Attr)xmlNode.getAttributes().item(i); } String text=“”; for (int i = 0; i < attributes.length; i++) { Attr attribute=attributes[i]; text=attribute.getNodeName()+“@”+ attribute.getNodeValue(); al.add(text);//dưa vào danh sách các thuộc tính } mn.setAttributes(al);//cap nhật DefaultMutableTreeNode tn=new DefaultMutableTreeNode(mn); treeNode.add(tn); NodeList childNodes=xmlNode.getChildNodes(); if(childNodes!=null){ length=childNodes.getLength(); for (int i = 0; i < length; i++) { addNode(childNodes.item(i), tn); } } break; } case Node.CDATA_SECTION_NODE:{ String x=“<![CDATA["+ xmlNode.getNodeValue()+ "]]>”; mn.setNodeValue(x); break; } case Node.TEXT_NODE:{ String newText=xmlNode.getNodeValue().trim(); ((MyNode)treeNode.getUserObject()).setNodeValue(newText); break; } case Node.PROCESSING_INSTRUCTION_NODE:{ String text=xmlNode.getNodeValue(); ((MyNode)treeNode.getUserObject()).setNodeValue(text); break; } } } /** * @param args */ public static void main(String[] args) { new ParseTree().setVisible(true); } @Override public void valueChanged(TreeSelectionEvent e) { try { DefaultMutableTreeNode selNode=(DefaultMutableTreeNode)e.getPath().getLastPathComponent(); Object obj=selNode.getUserObject(); if (obj instanceof MyNode) { MyNode node=(MyNode)obj; String text=node.getNodeID()+“:”+node.getNodeValue(); if(node.getAttributes()!=null&&node.getAttributes().size()>0) text+=“\n”+node.getAttributes().toString(); taContent.setText(text); } else taContent.setText(obj.toString()); } catch (Exception e1) { e1.printStackTrace(); } } @Override public void actionPerformed(ActionEvent e) { Object o=e.getSource(); if(o.equals(itemOpen)){ JFileChooser fc=new JFileChooser(); if(fc.showOpenDialog(null)==JFileChooser.APPROVE_OPTION){ String uri=fc.getSelectedFile().getAbsolutePath(); buildtree(uri); tree.expandRow(0); } } else if(o.equals(itemExit)){ System.exit(1); } } }

Trong đó lớp MyNode.java có nội dung sau

package dom.swing;

import java.util.ArrayList;

public class MyNode {

private String nodeID;//ID

private String nodeValue;//giá trị vủa node

private ArrayList<String>attributes;//lưu giữ các thuộc tính của node

public String getNodeID() {

return nodeID;

}

public void setNodeID(String nodeID) {

this.nodeID = nodeID;

}

public String getNodeValue() {

return nodeValue;

}

public void setNodeValue(String nodeValue) {

this.nodeValue = nodeValue;

}

public ArrayList<String> getAttributes() {

return attributes;

}

public void setAttributes(ArrayList<String> attributes) {

this.attributes = attributes;

}

@Override

public int hashCode() {

final int prime = 31;

int result = 1;

result = prime * result + ((nodeID == null) ? 0 : nodeID.hashCode());

return result;

}

@Override

public boolean equals(Object obj) {

if (this == obj)

return true;

if (obj == null)

return false;

if (getClass() != obj.getClass())

return false;

final MyNode other = (MyNode) obj;

if (nodeID == null) {

if (other.nodeID != null)

return false;

} else if (!nodeID.equals(other.nodeID))

return false;

return true;

}

public MyNode(String nodeID, String nodeValue, ArrayList<String> attributes) {

super();

this.nodeID = nodeID;

this.nodeValue = nodeValue;

this.attributes = attributes;

}

public MyNode() {

super();

}

@Override

public String toString() {

return this.nodeID;

}

}

Kết quả thu được như hình sau