使用数据库的spring+hibernate的树形结构

花了两个小时做了个spring+hibernate的树形结构,以下代码随手写的,还没来得及调试,欢迎各位提建议!

DAO代码:
[code:1]
package infoweb.admin.dao;

import java.util.List;
import java.util.Iterator;
import infoweb.pojo.Board;

import net.sf.hibernate.HibernateException;
import net.sf.hibernate.Query;
import net.sf.hibernate.Session;

import org.springframework.orm.hibernate.HibernateCallback;
import org.springframework.orm.hibernate.support.HibernateDaoSupport;


/**
* <p>Title: 版块分类DAOImpl</p>
* <p>Description: 用树型结构实现</p>
* <p>Copyright: Copyright (c) 2004</p>
* <p>Company: </p>
* @author 段洪杰
* @version 1.0
*/


public class BoardTreeDAOImpl extends HibernateDaoSupport implements
IBoardTreeDAO {
/**
* 构造函数
*/
public BoardTreeDAOImpl() {
super();
}


/**
* 取根叶
* @return List
*/
public List getRoots() throws HibernateException {
String queryString =
"select board as Board where board.parent_id='root' order by board.id desc";
List roots = getHibernateTemplate().find(queryString);
return roots;
}


/**
* 存根叶
* @param board Board
*/
public void setRoot(Board board) {
board.setParentId("root");
getHibernateTemplate().save(board);
}


/**
* 取子叶
* @param parentid String
* @return List
*/
public Iterator getChildren(String parentid) {
/*
String queryString =
"select board as Board where board.parent_id='parentid' order by board.id desc";
List children = getHibernateTemplate().find(queryString);
return children;
*/
Board parent = (Board) getHibernateTemplate().load(Board.class, parentid);
return parent.getChildren().iterator();
}


/**
* 取子叶数
* @param parentid String
* @return int
*/

public int getChildsCount(String parentid) {
/*
String queryString =
"select count(*) Board where board.parent_id='parentid' order by board.id desc";
List children = getHibernateTemplate().find(queryString);
int count = ((Integer) children.iterator().next()).intValue();
return count;
*/
Board parent = (Board) getHibernateTemplate().load(Board.class, parentid);
return parent.getChildren().size();
}


/**
* 存子叶
* @param parentLeaf Leaf
*/
public void setChild(Board board, String parentid) {
board.setParentId(parentid);
getHibernateTemplate().save(board);
}


/**
*
* 删除该叶和它的子叶
* @param board Board
*/
public void deleteBranch(Board board) {

}


/**
* 根据子叶得到父叶
* @param child Board
* @return Board
*/
public Board getParentByChild(Board child) {

}


/**
* 通过子ID得到父叶
* @param id String
* @return Board
*/
public Board getParentByChildId(String id) {

}
}
[/code:1]



Board代码
[code:1]
package infoweb.pojo;

import java.io.Serializable;
import java.util.Date;
import java.util.Set;
import org.apache.commons.lang.builder.ToStringBuilder;


/** @author Hibernate CodeGenerator */
public class Board implements Serializable {

/** identifier field */
private String id;

/** nullable persistent field */
private String parentId;

/** nullable persistent field */
private String name;

/** nullable persistent field */
private Date createDate;

/** persistent field */
private Set infos;

/** persistent field */
private Set children;

/** full constructor */
public Board(String parentId, String name, Date createDate, Set infos, Set children) {
this.parentId = parentId;
this.name = name;
this.createDate = createDate;
this.infos = infos;
this.children = children;
}

/** default constructor */
public Board() {
}

/** minimal constructor */
public Board(Set infos, Set children) {
this.infos = infos;
this.children = children;
}

public String getId() {
return this.id;
}

public void setId(String id) {
this.id = id;
}

public String getParentId() {
return this.parentId;
}

public void setParentId(String parentId) {
this.parentId = parentId;
}

public String getName() {
return this.name;
}

public void setName(String name) {
this.name = name;
}

public Date getCreateDate() {
return this.createDate;
}

public void setCreateDate(Date createDate) {
this.createDate = createDate;
}

public Set getInfos() {
return this.infos;
}

public void setInfos(Set infos) {
this.infos = infos;
}

public Set getChildren() {
return this.children;
}

public void setChildren(Set children) {
this.children = children;
}

public String toString() {
return new ToStringBuilder(this)
.append("id", getId())
.toString();
}

}

[/code:1]

Board.hbm.xml代码
[code:1]
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >

<hibernate-mapping>
<!--
Created by the Middlegen Hibernate plugin 2.1

http://boss.bekk.no/boss/middlegen/
http://www.hibernate.org/
-->

<class
name="infoweb.pojo.Board"
table="board"
>

<id
name="id"
type="java.lang.String"
column="id"
>
<generator class="uuid.hex" />
</id>

<property
name="parentId"
type="java.lang.String"
column="parent_id"
length="50"
/>

<property
name="name"
type="java.lang.String"
column="name"
length="255"
/>
<property
name="createDate"
type="java.sql.Timestamp"
column="createDate"
length="19"
/>

<!-- Associations -->

<!-- bi-directional one-to-many association to Info -->
<set
name="infos"
lazy="true"
inverse="true"
cascade="none"
>
<key>
<column name="board_id" />
</key>
<one-to-many
class="infoweb.pojo.Info"
/>
</set>


<set cascade="save-update"
inverse="true"
lazy="true"
name="children"
>
<key column="parent_id" />
<one-to-many
class="infoweb.pojo.Board" />
</set>



</class>

</hibernate-mapping>

[/code:1]

这个板块最热心最无私的莫过于dhj1。
呵呵 从他的文章学到了不少东西

今早又花了两个小时,把代码全部调试通过了,现在把测试代码贴在下面:

[code:1]
package infoweb.admin.dao;

import junit.framework.*;
import infoweb.pojo.*;
import java.util.*;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
import net.sf.hibernate.HibernateException;
/**
* <p>Title: </p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2004</p>
* <p>Company: </p>
* @author 段洪杰
* @version 1.0
*/

public class TestBoardTreeDAOImpl extends TestCase {
private IBoardTreeDAO boardTreeDAO = null;
private ApplicationContext ac;

protected void setUp() throws Exception {
super.setUp();
ac = new FileSystemXmlApplicationContext("F:/jbproject/info_web/infoweb/WEB-INF/applicationContext-hibernate.xml");
boardTreeDAO =(BoardTreeDAOImpl) ac.getBean("boardTreeDAO");
}

protected void tearDown() throws Exception {
boardTreeDAO = null;
super.tearDown();
}


public void testgetBoardById() {
Board board=boardTreeDAO.getBoardById("40288548ff334c2300ff334c27700003");
String actualReturn=board.getName();
String expectedReturn= "中国新闻";
assertEquals("return value", expectedReturn, actualReturn);
}


public void testDeleteBranch() {
Board board= boardTreeDAO.getBoardById("40288548ff38b15e00ff38b163c00003");
boardTreeDAO.deleteBranch(board);

}

public void testGetChildren() {
String parentid = "40288548ff334c2300ff334c27700003";
List actualReturn=new ArrayList();
List expectedReturn = new ArrayList();
expectedReturn.add("港台新闻");
expectedReturn.add("云南新闻");
Iterator it = boardTreeDAO.getChildren(parentid);

while(it.hasNext()){
Board board=(Board)it.next();
actualReturn.add(board.getName());
}

assertEquals("return value", expectedReturn, actualReturn);

}

public void testGetChildrenCount() {
String parentid = "40288548ff334c2300ff334c27700003";
int expectedReturn = 2;
int actualReturn = boardTreeDAO.getChildrenCount(parentid);
assertEquals("return value", expectedReturn, actualReturn);
}

public void testGetParentByChild() {
Board board=boardTreeDAO.getBoardById("40288548ff38b26900ff38b26b8b0001");
String expectedReturn = "ROOT789";
String actualReturn = boardTreeDAO.getParentByChild(board).getName();
assertEquals("return value", expectedReturn, actualReturn);

}

public void testGetParentByChildId() {
String id = "40288548ff38b26900ff38b26b8b0001";
String expectedReturn = "ROOT789";
Board actualReturn =(Board) boardTreeDAO.getParentByChildId(id);
assertEquals("return value", expectedReturn, actualReturn.getName());

}

public void testGetRoots() throws HibernateException{
List expectedReturn =new ArrayList();
List actualReturn=new ArrayList();
expectedReturn.add("中国新闻");
expectedReturn.add("国际新闻");

expectedReturn.add("我是一个人111");
Iterator roots = boardTreeDAO.getRoots();
while(roots.hasNext()){
Board board=(Board)roots.next();
actualReturn.add(board.getName());
}
assertEquals("ROOTS版块值", expectedReturn, actualReturn);

}

public void testSetChild() {
Board board = new Board();
board.setName("r00t123-1-111");
String parentid = "40288548ff38b15e00ff38b163c00003";
boardTreeDAO.setChild(board, parentid);

}

public void testSetRoot() {
Board board = new Board();
board.setName("ROOT789");
boardTreeDAO.setRoot(board);

}

}

[/code:1]

我的做法:
1.加入level(层次),levelcode(层次码),orderno(层内顺序号)，以提供快速的子父关系查找,这几个参数的计算在一个facade bean 提供.
2.提供取某一节点子树的方法
3.提供先根和后根遍历