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