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SSH(Spring + Struts + Hibernate)小试(转)

之前对Spring Struts Hibernate都稍有了解,Spring的IOC给我留下了很深的印象,容器管理的对象生成
方法极大地简化了程序逻辑,Spring也提供了用于Web的Spring MVC 框架,由于我感觉其易用性还是不及
Struts,所以我还是选择Struts作为前端WEB框架,Hibernate我一直没有在Web应用中试过,这次当然不会
错过机会了。


开发环境的塔建我就不多说了,具体可以参考我以前的几篇日志。

在Eclipse中新建一个动态Web工程,将Struts 、Spring、Hibernate需要的jar都添加到WEB-INF/lib目录下,
将Struts标签所需的tld文件、struts-config.xml文件(可以由StrutsIDE生成)添加到WEB-INF下,另外在
此目录下添加一个Spring的配置文件applicationContext.xml。


我参考的例子是夏昕的《深入浅出Hibernate》上的第6章,很好的一个论坛示例。

首先按照书上的ER模型,在数据库(MySQL)中建立相应的数据库。


create database forum;

use forum;

create table user(
 id int not null auto_increment primary key,
 name varchar(50),
 pwd varchar(50),
 email varchar(50)

)type=innodb;


create table board(
 id int not null auto_increment primary key, 
 parent_id int,
 create_by int not null,
 name varchar(50) not null,
 remark varchar(255),
 create_time datetime,

 index(parent_id),
 index(create_by),

 foreign key(parent_id) references board(id) on delete cascade,
 foreign key(create_by) references user(id) on delete no action
 
)type=innodb;


create table article(
 id int not null auto_increment primary key, 
 parent_id int ,
 board_id int not null,
 article_type int not null,
 title varchar(255),
 body text,
 create_by int not null,

 create_time datetime,
 hits int unsigned,
 bytes int unsigned,
 last_update_by int not null,
 last_update_time datetime,

 index(parent_id),
 index(board_id),
 index(create_by),
 index(last_update_by),

 foreign key(parent_id) references article(id) on delete no action,
 foreign key(board_id) references board(id) on delete cascade,
 foreign key(create_by) references user(id) on delete no action,
 foreign key(last_update_by) references user(id) on delete no action
 
)type=innodb;

之后,我选择了用Hibernate Sychonizer来生成映射文件和实体类,然后对生成的类进行修改(删掉了生成的Base类),
实际上Hibernate Sychonizer生成的映射文件也有错误,需要修改,我也是后来在使用中发现的。

//User.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
 "-//Hibernate/Hibernate Mapping DTD//EN"
 "
http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd " >

<hibernate-mapping package="com.lzy.forum.domain">
 <class
  name="User"
  table="user"
 >

  <id
   name="Id"
   type="integer"
   column="id"
  >
   <generator class="native"/>
  </id>

  <property
   name="Name"
   column="name"
   type="string"
   not-null="false"
   length="50"
  />
  <property
   name="Pwd"
   column="pwd"
   type="string"
   not-null="false"
   length="50"
  />
  <property
   name="Email"
   column="email"
   type="string"
   not-null="false"
   length="50"
  />
 

  <set name="ArticlesByLastUpdateBy" inverse="true" lazy="true">
   <key column="last_update_by"/>
   <one-to-many class="Article"/>
  </set>

  <set name="ArticlesByCreateBy" inverse="true" lazy="true">
   <key column="create_by"/>这里的create_by是后来修改的,Hibernate Sychonizer生成的有错,后面有几处同样的错误】
   <one-to-many class="Article"/>
  </set>

  <set name="Boards" inverse="true" lazy="true">
   <key column="create_by"/>【这里的create_by是后来修改的】

   <one-to-many class="Board"/>
  </set>


 </class> 
</hibernate-mapping>

//User.java
package com.lzy.forum.domain;


public class User{
 private static final long serialVersionUID = 1L;

//  primary key
 private java.lang.Integer id;

 // fields
 private java.lang.String name;
 private java.lang.String pwd;
 private java.lang.String email;

 // collections
 private java.util.Set<Article> articlesByLastUpdateBy;
 private java.util.Set<Article> articlesByCreateBy;
 private java.util.Set<Board> boards;
 
 
 public java.util.Set<Article> getArticlesByCreateBy() {
  return articlesByCreateBy;
 }
 public void setArticlesByCreateBy(java.util.Set<Article> articlesByCreateBy) {
  this.articlesByCreateBy = articlesByCreateBy;
 }
 public java.util.Set<Article> getArticlesByLastUpdateBy() {
  return articlesByLastUpdateBy;
 }
 public void setArticlesByLastUpdateBy(
   java.util.Set<Article> articlesByLastUpdateBy) {
  this.articlesByLastUpdateBy = articlesByLastUpdateBy;
 }
 public java.util.Set<Board> getBoards() {
  return boards;
 }
 public void setBoards(java.util.Set<Board> boards) {
  this.boards = boards;
 }
 public java.lang.String getEmail() {
  return email;
 }
 public void setEmail(java.lang.String email) {
  this.email = email;
 }
 public java.lang.Integer getId() {
  return id;
 }
 public void setId(java.lang.Integer id) {
  this.id = id;
 }
 public java.lang.String getName() {
  return name;
 }
 public void setName(java.lang.String name) {
  this.name = name;
 }
 public java.lang.String getPwd() {
  return pwd;
 }
 public void setPwd(java.lang.String pwd) {
  this.pwd = pwd;
 }


}

//Board.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
 "-//Hibernate/Hibernate Mapping DTD//EN"
 "
http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd " >

<hibernate-mapping package="com.lzy.forum.domain">
 <class
  name="Board"
  table="board"
 >
   <meta attribute="sync-DAO">false</meta>
  <id
   name="Id"
   type="integer"
   column="id"
  >
   <generator class="native"/>
  </id>

  <property
   name="Name"
   column="name"
   type="string"
   not-null="true"
   length="50"
  />
  <property
   name="Remark"
   column="remark"
   type="string"
   not-null="false"
   length="255"
  />
  <property
   name="CreateTime"
   column="create_time"
   type="timestamp"
   not-null="false"
   length="19"
  />
  <many-to-one
   name="CreateBy"
   column="create_by"
   class="User"
   not-null="true"
  >
  </many-to-one>
  <many-to-one
   name="Parent"
   column="parent_id"
   class="Board"   
   not-null="false"
   lazy="false">
  </many-to-one>
 

  <set name="Articles" inverse="true" lazy="true" order-by="id">
   <key column="board_id"/>【这里的board_id是后来修改的】
   <one-to-many class="Article"/>
  </set>

  <set name="ChildBoards" inverse="true"  lazy="true" order-by="id">
   <key column="parent_id"/>这里的parent_id是后来修改的】
   <one-to-many class="Board"/>
  </set>


 </class> 
</hibernate-mapping>

//Board.java
package com.lzy.forum.domain;

 


public class Board  {
 private static final long serialVersionUID = 1L;

//  primary key
 private java.lang.Integer id;

 // fields
 private java.lang.String name;
 private java.lang.String remark;
 private java.util.Date createTime;

 // many to one
 private com.lzy.forum.domain.User createBy;
 private com.lzy.forum.domain.Board parent;

 // collections
 private java.util.Set<com.lzy.forum.domain.Article> articles;
 private java.util.Set<com.lzy.forum.domain.Board> childBoards;
 
 
 public java.util.Set<com.lzy.forum.domain.Article> getArticles() {
  return articles;
 }
 public void setArticles(java.util.Set<com.lzy.forum.domain.Article> articles) {
  this.articles = articles;
 }
 public java.util.Set<com.lzy.forum.domain.Board> getChildBoards() {
  return childBoards;
 }
 public void setChildBoards(java.util.Set<com.lzy.forum.domain.Board> childBoards) {
  this.childBoards = childBoards;
 }
 public com.lzy.forum.domain.User getCreateBy() {
  return createBy;
 }
 public void setCreateBy(com.lzy.forum.domain.User createBy) {
  this.createBy = createBy;
 }
 public java.util.Date getCreateTime() {
  return createTime;
 }
 public void setCreateTime(java.util.Date createTime) {
  this.createTime = createTime;
 }
 public java.lang.Integer getId() {
  return id;
 }
 public void setId(java.lang.Integer id) {
  this.id = id;
 }
 public java.lang.String getName() {
  return name;
 }
 public void setName(java.lang.String name) {
  this.name = name;
 }
 public com.lzy.forum.domain.Board getParent() {
  return parent;
 }
 public void setParent(com.lzy.forum.domain.Board parent) {
  this.parent = parent;
 }
 public java.lang.String getRemark() {
  return remark;
 }
 public void setRemark(java.lang.String remark) {
  this.remark = remark;
 }


}

//Article.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
 "-//Hibernate/Hibernate Mapping DTD//EN"
 "
http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd " >

<hibernate-mapping package="com.lzy.forum.domain">
 <class
  name="Article"
  table="article"
 >
  <meta attribute="sync-DAO">false</meta>
  <id
   name="Id"
   type="integer"
   column="id"
  >
   <generator class="native"/>
  </id>

  <property
   name="ArticleType"
   column="article_type"
   type="integer"
   not-null="true"
   length="11"
  />
  <property
   name="Title"
   column="title"
   type="string"
   not-null="false"
   length="255"
  />
  <property
   name="Body"
   column="body"
   type="string"
   not-null="false"
  />
  <property
   name="Hits"
   column="hits"
   type="integer"
   not-null="false"
   length="10"
  />
  <property
   name="Bytes"
   column="bytes"
   type="integer"
   not-null="false"
   length="10"
  />
  <property
   name="CreateTime"
   column="create_time"
   type="timestamp"
   not-null="false"
   length="19"
  />
  <property
   name="LastUpdateTime"
   column="last_update_time"
   type="timestamp"
   not-null="false"
   length="19"
  />
  <many-to-one
   name="LastUpdateBy"
   column="last_update_by"
   class="User"
   not-null="true"
  >
  </many-to-one>
  <many-to-one
   name="CreateBy"
   column="create_by"
   class="User"
   not-null="true"
  >
  </many-to-one>
  <many-to-one
   name="Parent"
   column="parent_id"
   class="Article"
   not-null="false"
  >
  </many-to-one>
  <many-to-one
   name="Board"
   column="board_id"
   class="Board"
   not-null="true"
  >
  </many-to-one>
 

  <set name="Articles" inverse="true" lazy="false" order-by="id">
   <key column="parent_id"/>【这里的parent_id是后来修改的】
   <one-to-many class="Article"/>
  </set>


 </class> 
</hibernate-mapping>



//Article.java
package com.lzy.forum.domain;

import java.util.Date;

 


public class Article  {
 private static final long serialVersionUID = 1L;
 // primary key
 private java.lang.Integer id;

 // fields
 private java.lang.Integer articleType;
 private java.lang.String title;
 private java.lang.String body;
 private java.lang.Integer hits;
 private java.lang.Integer bytes;
 private java.util.Date lastUpdateTime;
 private java.util.Date createTime;
 

 // many to one
 private com.lzy.forum.domain.User lastUpdateBy;
 private com.lzy.forum.domain.User createBy;
 private com.lzy.forum.domain.Article parent;
 private com.lzy.forum.domain.Board board;

 // collections
 private java.util.Set<com.lzy.forum.domain.Article> articles;

 public java.util.Set<com.lzy.forum.domain.Article> getArticles() {
  return articles;
 }

 public void setArticles(java.util.Set<com.lzy.forum.domain.Article> articles) {
  this.articles = articles;
 }

 public java.lang.Integer getArticleType() {
  return articleType;
 }

 public void setArticleType(java.lang.Integer articleType) {
  this.articleType = articleType;
 }

 public com.lzy.forum.domain.Board getBoard() {
  return board;
 }

 public void setBoard(com.lzy.forum.domain.Board board) {
  this.board = board;
 }

 public java.lang.String getBody() {
  return body;
 }

 public void setBody(java.lang.String body) {
  this.body = body;
 }

 public java.lang.Integer getBytes() {
  return bytes;
 }

 public void setBytes(java.lang.Integer bytes) {
  this.bytes = bytes;
 }

 public com.lzy.forum.domain.User getCreateBy() {
  return createBy;
 }

 public void setCreateBy(com.lzy.forum.domain.User createBy) {
  this.createBy = createBy;
 }

 public java.lang.Integer getHits() {
  return hits;
 }

 public void setHits(java.lang.Integer hits) {
  this.hits = hits;
 }

 public java.lang.Integer getId() {
  return id;
 }

 public void setId(java.lang.Integer id) {
  this.id = id;
 }

 public com.lzy.forum.domain.User getLastUpdateBy() {
  return lastUpdateBy;
 }

 public void setLastUpdateBy(com.lzy.forum.domain.User lastUpdateBy) {
  this.lastUpdateBy = lastUpdateBy;
 }

 public java.util.Date getLastUpdateTime() {
  return lastUpdateTime;
 }

 public void setLastUpdateTime(java.util.Date lastUpdateTime) {
  this.lastUpdateTime = lastUpdateTime;
 }

 public com.lzy.forum.domain.Article getParent() {
  return parent;
 }

 public void setParent(com.lzy.forum.domain.Article parent) {
  this.parent = parent;
 }

 public java.lang.String getTitle() {
  return title;
 }

 public void setTitle(java.lang.String title) {
  this.title = title;
 }
 public java.util.Date getCreateTime(){
  return createTime;
 }

 public void setCreateTime(java.util.Date createTime) {
  // TODO Auto-generated method stub
  this.createTime = createTime;
 }
 

}

接下来将会在web中加入Spring支持和为实体类提供DAO支持。

Spring和Struts结合有几种方法,我选了最常用的PlugIn方式,在struts-config.xml中加入

<plug-in className="org.springframework.web.struts.ContextLoaderPlugIn">
      <set-property property="contextConfigLocation"
            value="/WEB-INF/action-servlet.xml" />
 </plug-in>

WEB-INF目录下的action-servlet.xml就是Spring的配置文件,下面给出的是整个的action-servlet.xml文件:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING/DTD BEAN/EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>

//Data Source

 <bean id="dataSource"
  class="org.springframework.jdbc.datasource.DriverManagerDataSource">
  <property name="driverClassName">
   <value>com.mysql.jdbc.Driver</value>
  </property>
  <property name="url">
   <value>jdbc:mysql://localhost:3306/forum</value>
  </property>
  <property name="username">
   <value>test</value>
  </property>
  <property name="password">
   <null />
  </property>
 </bean>

// For Hibernate
 <bean id="sessionFactory"
  class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
  <property name="dataSource">
   <ref local="dataSource" />
  </property>
  <property name="mappingResources">
   <list>
    <value>com/lzy/forum/domain/User.hbm.xml</value>
    <value>com/lzy/forum/domain/Article.hbm.xml</value>
    <value>com/lzy/forum/domain/Board.hbm.xml</value>
   </list>
  </property>
  <property name="hibernateProperties">
   <props>
    <prop key="hibernate.dialect">
     org.hibernate.dialect.MySQLDialect
    </prop>
    <prop key="hibernate.show_sql">true</prop>
   </props>
  </property>
 </bean>

 <bean id="transactionManager"
  class="org.springframework.orm.hibernate3.HibernateTransactionManager">
  <property name="sessionFactory">
   <ref local="sessionFactory" />
  </property>
 </bean>

 

// For DAO
 <bean id="userDAO"
  class="com.lzy.forum.dao.impl.UserDAOHibernate">
  <property name="sessionFactory">
   <ref local="sessionFactory" />
  </property>
 </bean>

 

 <bean id="boardDAO"
  class="com.lzy.forum.dao.impl.BoardDAOHibernate">
  <property name="sessionFactory">
   <ref local="sessionFactory" />
  </property>
 </bean>

 <bean id="articleDAO"
  class="com.lzy.forum.dao.impl.ArticleDAOHibernate">
  <property name="sessionFactory">
   <ref local="sessionFactory" />
  </property>
 </bean>

//For Struts Action

 <bean name="/regist" class="com.lzy.forum.action.RegistAction"
  singleton="false">
  <property name="userDAO">
   <ref local="userDAO" />
  </property>

 </bean>


 <bean name="/login" class="com.lzy.forum.action.LoginAction"
  singleton="false">
  <property name="userDAO">
   <ref local="userDAO" />
  </property>

 </bean>

 <bean name="/boardManage"
  class="com.lzy.forum.action.BoardManageAction" singleton="false">
  <property name="userDAO">
   <ref local="userDAO" />
  </property>
  <property name="boardDAO">
   <ref local="boardDAO" />
  </property>

 </bean>

 <bean name="/boardNavigate"
  class="com.lzy.forum.action.BoardNavigateAction" singleton="false">
  <property name="boardDAO">
   <ref local="boardDAO" />
  </property>

 </bean>

 <bean name="/boardDisplay"
  class="com.lzy.forum.action.BoardDisplayAction" singleton="false">
  <property name="boardDAO">
   <ref local="boardDAO" />
  </property>

 </bean>

 <bean name="/articleManage"
  class="com.lzy.forum.action.ArticleManageAction" singleton="false">
  <property name="userDAO">
   <ref local="userDAO" />
  </property>
  <property name="boardDAO">
   <ref local="boardDAO" />
  </property>
  <property name="articleDAO">
   <ref local="articleDAO" />
  </property>


 </bean>


</beans>

经过这样的配置之后,Hibernate事务交由Spring管理,sessionFactory从Spring容器获得。下面通过其中的一个DAO实例来看看这样做带来的方便。


//BoardDAO.java

package com.lzy.forum.dao;

import java.util.ArrayList;

import com.lzy.forum.domain.Board;

public interface BoardDAO {
 
 public boolean isBoardExist(String name);
 
 public void addBoard(Board board);
 
 public void deleteBoard(Board board);
 
 public Board loadBoard(int id);
 
 public Board loadBoard(String name);
 
 public Board loadBoardWithArticles(int id);
 
 public ArrayList getRootBoardsList();
 
 
 
}


//BoardDAOHibernate.java

package com.lzy.forum.dao.impl;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.ListIterator;
import java.util.Set;

import org.hibernate.Hibernate;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import com.lzy.forum.dao.BoardDAO;
import com.lzy.forum.domain.Board;

public class BoardDAOHibernate extends HibernateDaoSupport implements BoardDAO {

 public void deleteBoard(Board board) {
  // TODO Auto-generated method stub
  this.getHibernateTemplate().delete(board);
 }

 public void addBoard(Board board) {
  // TODO Auto-generated method stub
  this.getHibernateTemplate().saveOrUpdate(board);

 }

 public boolean isBoardExist(String name) {
  // TODO Auto-generated method stub
  ArrayList list = (ArrayList) this.getHibernateTemplate().find(
    "from Board where name = ? ", new Object[] { name });
  if (list.size() > 0) {
   // System.out.println("find it");
   return true;
  }
  return false;
 }

 public Board loadBoard(int id) {
  // TODO Auto-generated method stub
  ArrayList list = (ArrayList) this.getHibernateTemplate().find(
    "from Board where id = ? ", new Object[] { id });

  Board b = null;
  if (list.size() > 0) {
   b = (Board) list.get(0);
  }

  return b;
 }

 public Board loadBoard(String name) {
  // TODO Auto-generated method stub
  ArrayList list = (ArrayList) this.getHibernateTemplate().find(
    "from Board where name = ? ", new Object[] { name });

  Board b = null;
  if (list.size() > 0) {
   b = (Board) list.get(0);
  }

  return b;
 }

 public ArrayList getRootBoardsList() {
  // TODO Auto-generated method stub
  ArrayList list = (ArrayList) this.getHibernateTemplate().find(
    "from Board b left join fetch b.ChildBoards where b.Parent = null order by b.id");
  System.out.println(list.size() + " root boards found ");
  

  ListIterator index = list.listIterator();
  while (index.hasNext()) {

   Board s = (Board) index.next();
   //this.getSession(true);
   //Hibernate.initialize(s.getChildBoards());
   ///*
    Set children  = (Set) s.getChildBoards();
    Iterator it = children.iterator();
   
    while(it.hasNext()){
    Board b = (Board)it.next();
    //Hibernate.initialize(b);
    System.out.println(b.getName());
    }
    //*/

   //System.out.println(children.size() + "child(ren) found ");
   //s.setChildBoards(s.getChildBoards());
  }

  return list;
 }

 public Board loadBoardWithArticles(int id) {
  // TODO Auto-generated method stub
  ArrayList list = (ArrayList) this.getHibernateTemplate().find(
    "from Board b left join fetch b.Articles where b.Id = ? ", new Object[] { id });

  Board b = null;
  if (list.size() > 0) {
   b = (Board) list.get(0);
  }

  return b;

 }


}


BoardDAOHibernate继承 HibernateDaoSupport后,通过getHibernateTemplate()得到一个HibernateTemplate实例,然后执行CRUD操作,非常简单。需要注意的是,由于执行一次CRUD操作后,Hibernate session关闭,如果有使用延迟加载策略的对象没有加载,在后面的Web层很容易出现如下错误:
failed to lazily initialize a collection of role
从网上搜到的解决方法是Open Session In View,
<filter>
     <filter-name>hibernateFilter</filter-name>
     <filter-class> org.springframework.orm.hibernate3.support.OpenSessionInViewFilter
     </filter-class>

     <!-- singleSession默认为true,若设为false则等于没用OpenSessionInView -->
    <init-param>
       <param-name>singleSession</param-name>
       <param-value>true</param-value>
    </init-param>
  </filter>

   <filter-mapping>
     <filter-name>hibernateFilter</filter-name>
     <url-pattern>*.do</url-pattern>
   </filter-mapping>
我试了试,还是有一些问题,所以后来还是放弃了这种方法,所有在Web层中需要的对象都必须在Business层中加载完成。如下面的代码所示:

ArrayList list = (ArrayList) this.getHibernateTemplate().find(
    "from Board b left join fetch b.Articles where b.Id = ? ", new Object[] { id });


这样Hibernate和Spring的结合也算完成了。其他的一些DAO类和实现代码我没有给出,但是大同小异,和Board的实现类似。


最后将是Struts 和Spring的结合,将在下一篇给出。

前面通过PlugIn我们实现了Spring Context的加载,不过仅仅加载Context并没有什么实际
意义,我们还需要修改配置,将Struts Action交给Spring容器进行管理。下面将通过一个Regsit
实例加以说明。

首先准备好regist.jsp和login.jsp,在regist.jsp中 的form有name,password,password2,email域。

在struts-config.xml中添加配置:

<form-bean name="registForm" type="com.lzy.forum.form.RegistForm" />

<action path="/regist" name="registForm"
type="org.springframework.web.struts.DelegatingActionProxy"

validate="true" input="/regist.jsp" scope="request">
<forward name="failure" path="/regist.jsp" />
<forward name="success" path="/login.jsp" />
</action>


RegistForm,RegistAction按照原来Struts的方法去写,我在RegistAction中加入了一个UserDAO对象
userDAO,这个对象由Spring注入。

<bean name="/regist" class="com.lzy.forum.action.RegistAction"
singleton="false">
<property name="userDAO">
<ref local="userDAO" />
</property>
</bean>

基本上SSH的架构已经完成,经确认后可以自己测试一下了。

posted on 2006-07-21 01:45 liaojiyong 阅读(577) 评论(0)  编辑  收藏 所属分类: Spring


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