一个用dom编写的目录树形结构，请大家提提意见。
03-08-26
jander
目录可以在任何层次添加、删除。
category.dtd
<?xml version="1.0" encoding="GBK"?>
<!ELEMENT category ( category*)>
<!ATTLIST category
id ID #REQUIRED
name CDATA #REQUIRED
locked (true|false) "false"
disvisible (true|false) "false"
level CDATA #REQUIRED
>
<p>
|
category.xml
<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE category SYSTEM "category.dtd">
<category id="c0" name="category0" locked="false" disvisible="false" level="0">
<category id="c1" name="category1" locked="false" disvisible="false" level="1"/>
</category>
<p>
|
CategoryDetail
import java.util.List;
public class CategoryDetail {
private String id;
private String name;
private boolean locked;
private boolean disvisible;
private int level;
private List parentList;//所有父亲的集合，按继承顺序排列。
private List childList;//所有孩子的集合
public CategoryDetail(String id, String name, boolean locked, boolean disvisible, int level, List parentList, List childList) {
this.id = id;
this.name = name;
this.locked = locked;
this.disvisible = disvisible;
this.level = level;
this.parentList = parentList;
this.childList = childList;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public boolean isLocked() {
return locked;
}
public void setLocked(boolean locked) {
this.locked = locked;
}
public boolean isDisvisible() {
return disvisible;
}
public void setDisvisible(boolean disvisible) {
this.disvisible = disvisible;
}
public int getLevel() {
return level;
}
public void setLevel(int level) {
this.level = level;
}
public List getParentList() {
return parentList;
}
public void setParentList(List parentList) {
this.parentList = parentList;
}
public List getChildList() {
return childList;
}
public void setChildList(List childList) {
this.childList = childList;
}
public String printTag(int count,String tag){
StringBuffer sb=new StringBuffer();
for(int i=0;i<count;i++){
sb.append(tag);
}
return sb.toString();
}
}
<p>
|
CategoryData
public class CategoryData {
public static CategoryData Empty=new CategoryData();
private String id;
private String name;
private boolean locked;
private boolean disvisible;
private int level;
public CategoryData() {
}
public CategoryData(String id, String name, boolean locked, boolean disvisible, int level) {
this.id = id;
this.name = name;
this.locked = locked;
this.disvisible = disvisible;
this.level = level;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public boolean isLocked() {
return locked;
}
public void setLocked(boolean locked) {
this.locked = locked;
}
public boolean isDisvisible() {
return disvisible;
}
public void setDisvisible(boolean disvisible) {
this.disvisible = disvisible;
}
public int getLevel() {
return level;
}
public void setLevel(int level) {
this.level = level;
}
public String toString() {
return "CategoryData: id="+id+" name="+name;
}
}
<p>
|
CategoryTree
import org.w3c.dom.*;
import javax.xml.parsers.*;
import java.io.*;
import java.util.*;
public class CategoryTree {
private Document doc;
private String xmlFile = "D:\\myapp\\xmltree\\build\\category.xml";
private final static String ID_ATTR = "id";
private final static String NAME_ATTR = "name";
private final static String LOCKED_ATTR = "locked";
private final static String DISVISIBLE_ATTR = "disvisible";
private final static String LEVEL_ATTR = "level";
private final static String CATEGORY_ELEMENT = "category";
public CategoryTree() {
load();
}
public CategoryDetail getCategoryDetail(String id) throws CategoryNotFoundException {
Element element = doc.getElementById(id);
if (element == null)
throw new CategoryNotFoundException();
return new CategoryDetail(
id,
element.getAttribute(NAME_ATTR),
Boolean.getBoolean(element.getAttribute(LOCKED_ATTR)),
Boolean.getBoolean(element.getAttribute(DISVISIBLE_ATTR)),
Integer.parseInt(element.getAttribute(LEVEL_ATTR)),
getParentList(element),
getChildList(element)
);
}
public CategoryData getCategoryData(String id) throws CategoryNotFoundException {
Element element = doc.getElementById(id);
if (element == null)
throw new CategoryNotFoundException();
else
return new CategoryData(
id,
element.getAttribute(NAME_ATTR),
Boolean.getBoolean(element.getAttribute(LOCKED_ATTR)),
Boolean.getBoolean(element.getAttribute(DISVISIBLE_ATTR)),
Integer.parseInt(element.getAttribute(LEVEL_ATTR))
);
}
public void createCategory(String name, String parentID) throws CategoryNotFoundException {
Element parent = doc.getElementById(parentID);
if (parent == null)
throw new CategoryNotFoundException();
int parentLevel = Integer.parseInt(parent.getAttribute(LEVEL_ATTR));
Element element = doc.createElement(CATEGORY_ELEMENT);
//测试时，用时间作ID.
element.setAttribute(ID_ATTR, "c" + String.valueOf(System.currentTimeMillis()));
element.setAttribute(NAME_ATTR, name);
element.setAttribute(LOCKED_ATTR, "true");
element.setAttribute(DISVISIBLE_ATTR, "true");
element.setAttribute(LEVEL_ATTR, String.valueOf(++parentLevel));
parent.appendChild(element);
store();
}
public void removeCategory(String id) throws CategoryNotFoundException {
Element element = doc.getElementById(id);
if (element == null)
throw new CategoryNotFoundException();
Node parent = element.getParentNode();
parent.removeChild(element);
store();
}
private void load() {
try {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setValidating(true);
factory.setNamespaceAware(false);
factory.setIgnoringElementContentWhitespace(true);
DocumentBuilder builder = factory.newDocumentBuilder();
doc = builder.parse(new File(xmlFile));
} catch (Exception e) {
e.printStackTrace();
System.out.println("can not load xml resource.");
}
}
private void store() {
try {
//实现一个DOMSerializer类，来存储xml。
DOMSerializer serializer = new DOMSerializer("GBK");
serializer.serialize(doc, new File(xmlFile));
} catch (Exception e) {
e.printStackTrace();
}
}
private List getChildList(Element element) {
List childList = new ArrayList();
NodeList nodeList = element.getChildNodes();
for (int i = 0; i < nodeList.getLength(); i++) {
Node node = nodeList.item(i);
if (node.getNodeType() == Node.ELEMENT_NODE) {
Element child = (Element) node;
childList.add(
new CategoryData(
child.getAttribute(ID_ATTR),
child.getAttribute(NAME_ATTR),
Boolean.getBoolean(child.getAttribute(LOCKED_ATTR)),
Boolean.getBoolean(child.getAttribute(DISVISIBLE_ATTR)),
Integer.parseInt(child.getAttribute(LEVEL_ATTR))
)
);
}
}
return childList;
}
private List getParentList(Element element) throws CategoryNotFoundException {
int level = Integer.parseInt(element.getAttribute("level"));
LinkedList parentList = new LinkedList();
Element tmp = null;
for (int i = 0; i < level; i++) {
tmp = (Element) element.getParentNode();
parentList.addFirst(getCategoryData(tmp.getAttribute("id")));
element = tmp;
}
return parentList;
}
public static void main(String[] args) throws Exception {
CategoryTree tree = new CategoryTree();
long start = System.currentTimeMillis();
tree.createCategory("我的文档", "c0");
tree.removeCategory("c3");
CategoryDetail c = tree.getCategoryDetail("c0");
Iterator iter = c.getChildList().iterator();
while (iter.hasNext()) {
System.out.println(iter.next());
}
long end = System.currentTimeMillis() - start;
System.out.println("run :" + end + " ms");
}
}
<p>
|
neuhawk
2003-08-26 18:00
应该跟用户权限结合起来。
比如权限分配，只能由administrator看见。
jander
2003-08-26 18:13
这只是一个简单的演示。
如果要加权限，可以直接在可以加上readRole,addRole,adminRole等属性，就可以了。
jander
2003-08-26 22:00
感觉用dom解析，速度慢了点，占内存。
还是应该用数据库来产生目录的xml文档。然后在页面格式化显示xml文档的速度快。
banq
2003-08-27 08:58
非常不错
XML实现树形结构有其优势，但是很多情况下，我们并不需要知道整个树形结构，因为整个树形结构显示出来也许非常复杂，一般只关系某个层次的父子、兄弟关系。
树形结构比较麻烦的是数据库节点实现和前台页面节点管理相结合。
使用数据库节点管理的好处是可以接受非常大的树结构数据。
节点如何和资源挂钩，也是一个比较麻烦的事情。
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