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转自：http://www.softhouse.com.cn/html/200410/2004102517145700001335.html
使用jdom操作xml数据，生成含jtree的applet
在我们工作中，常常会碰到树形组件的生成问题，如果你在开发web application,纯粹使用javascript来生成树形组件是非常繁琐的，而且交互性也不不太好。所以许多产品使applet来实现树形组件的功能。比如说，weblogic,jboss等产品的console.所以，把树形数据组织成xml文件，用jdom剖析它，最后生成applet就非常有通用的意义。下面，我就给出一个例子，抛砖引玉。1.准备一个存有属性数据的xml文件，把它放在classpath中，我这里是org.xml。[pre]<?xml version="1.0" encoding="utf-8"?><!–sample xml file generated by xmlspy v5 rel. 3 u (http://www.xmlspy.com)–><node xmlns="http://www.javabox.com/schemas/org" xmlns:xsi="http://www.w3.org/2001/xmlschema-instance" xsi:schemalocation="http://www.javabox.com/schemas/orge:\mydemo\org.xsd" name="组织机构" id="-1" desc="" link="#"> <node name="总经理" id="1" desc="" link="#"> <node name="管理副总经理" id="2" desc="" link="#"/> <node name="生产副总经理" id="3" desc="" link="#"> <node name="项目部" id="7" desc="" link="#"/> <node name="机械公司" id="8" desc="" link="#"/> <node name="贝盟公司" id="9" desc="" link="#"/> <node name="洛斯韦公司" id="9" desc="" link="#"/> </node> <node name="总工程师" id="4" desc="" link="#"/> <node name="总会计师" id="5" desc="" link="#"/> <node name="总经济师" id="6" desc="" link="#"/> </node></node>[/pre]2.确保你可以使用jdom解析器，你如果没有可以去这里下载。3.用于代表树结点节点的javabean,treenode.javapackage com.javabox.jtree;public class treenode{ private string id; private string name; private string link; public treenode(string id,string name,string link){ this.id=id; this.name=name; this.link=link; } public string getid(){ return id; } public void setid(string id){ this.id=id; } public void setname(string name){ this.name=name; } public string getname(){ return name; } public string tostring(){ return name; } public string getlink(){ return link; } public void setlink(string link){ this.link=link; }}4.自己写的treecellrenderer,iconrender.javapackage com.javabox.jtree;import javax.swing.*;import java.awt.*;import javax.swing.tree.*;import javax.swing.tree.defaulttreecellrenderer;class iconrender extends defaulttreecellrenderer { //你需要替换成你的icon public static final icon leafselectedicon = new imageicon("greeball.jpg"); public static final icon leafunselectedicon = new imageicon("greyball.jpg"); public static final icon folderopen = new imageicon("folderopen.jpg"); public static final icon folderclose = new imageicon("folderclose.jpg"); public component gettreecellrenderercomponent(jtree tree, object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasfocus) { super.gettreecellrenderercomponent(tree, value, selected, expanded, leaf, row, hasfocus); if (leaf && selected) { seticon(iconrender.leafselectedicon); } else if (leaf) { seticon(iconrender.leafunselectedicon); } return this; } public iconrender() { super(); this.setleaficon(leafunselectedicon); this.setopenicon(folderopen); this.setclosedicon(folderclose); }}5.applettree.java,该文件解析xml文件，生成含jtree的applet，你可以把它嵌入到jsp,html文件中使用，也可以直接运行该文件。package com.javabox.jtree;import javax.swing.event.*;import java.awt.*;import java.applet.*;import javax.swing.*;import javax.swing.tree.*;import java.awt.event.*;import org.jdom.*;import org.jdom.input.*;import java.io.*;import java.util.*;import java.awt.*;import javax.swing.*;import javax.swing.border.*;import javax.swing.plaf.*;import javax.swing.plaf.basic.*;import javax.swing.plaf.metal.*;import java.io.*;import netscape.javascript.*;public class applettree extends applet implements treeselectionlistener{ private jtree tree; private treepath path; private panel toppanel; private defaultmutabletreenode top; private defaultmutabletreenode clicknode; private string link; public applettree(){ } public void init(){ try{ super.init(); this.setlayout(new gridlayout(1,1)); tree=createtree(new fileinputstream("org.xml")); tree.getselectionmodel().setselectionmode(treeselectionmodel.single_tree_selection); tree.putclientproperty("jtree.linestyle","angled"); tree.setshowsroothandles(true); tree.seteditable(false); tree.addtreeselectionlistener( this ); iconrender render=new iconrender(); tree.setcellrenderer(render); toppanel=new panel(new borderlayout()); toppanel.add(tree); this.add(toppanel); }catch(exception e){ e.printstacktrace(); } } public jtree createtree(inputstream is){ saxbuilder builder = new saxbuilder(); try { document doc = builder.build(is); element root=doc.getrootelement(); treenode rootnode=new treenode(root.getattributevalue("id"),root.getattributevalue("name"),root.getattributevalue("link")); top=new defaultmutabletreenode(rootnode); addnode(root,top); } catch (exception ex) { ex.printstacktrace(); } //你可以在这里改变jtree中连线的颜色，我请教国外的高手才找到的，很酷的哦:) uimanager.put( "tree.hash", new coloruiresource(color.red) ); return new jtree(top); } /** * * @param e 待加入树种的jdom元素 * @param rootnode 树根节点 */ private void addnode(element e,defaultmutabletreenode rootnode){ string id=e.getattributevalue("id"); string name=e.getattributevalue("name"); string link=e.getattributevalue("link"); treenode node=new treenode(id,name,link); //如有父节点 element father=e.getparent(); if(father!=null){ string fid=father.getattributevalue("id"); defaultmutabletreenode fathernode=gettreenode(fid,rootnode); if(fathernode!=null){ fathernode.add(new defaultmutabletreenode(node)); } } //如有子节点 iterator it=e.getchildren().iterator(); while(it.hasnext()){ element child=(element)it.next(); addnode(child,rootnode); } } /** * 根据id,查找树节点,//广度优先 * @param id 节点id * @param rootnode 树根节点 * @return defaultmutabletreenode */ private defaultmutabletreenode gettreenode(string id,defaultmutabletreenode rootnode){ defaultmutabletreenode returnnode=null; if(rootnode!=null){ enumeration enum=rootnode.breadthfirstenumeration(); while(enum.hasmoreelements()){ defaultmutabletreenode temp=(defaultmutabletreenode)enum.nextelement(); treenode node=(treenode)temp.getuserobject(); if(node.getid().equals(id)){ returnnode=temp; break; } } } return returnnode; } public void valuechanged( treeselectionevent event ){ if( event.getsource() == tree ){ path = event.getpath(); clicknode=(defaultmutabletreenode)path.getlastpathcomponent(); object uo=clicknode.getuserobject(); if(uo instanceof treenode){ treenode nd=(treenode)clicknode.getuserobject(); link=nd.getlink(); } //调用一个javascript函数； // jsobject.getwindow (this).eval ("javascript:window.open("+link+")") ; } } public static void main(string[] args ){ jframe frame=new jframe("test"); applettree tree=new applettree(); tree.init(); frame.getcontentpane().add(tree); frame.setsize(600,600); frame.show(); }}6.运行一个这个类，是不是很cool哦，你还可以把它嵌在网页中，调用javasript函数，达到刷新页面的目的。
