// 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>
經過這樣的配置之后，Hibernate事務交由Spring管理，sessionFactory從Spring容器獲得。下面通過其中的一個DAO實例來看看這樣做帶來的方便。
//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繼承 HibernateDaoSupport后，通過getHibernateTemplate()得到一個HibernateTemplate實例，然后執行CRUD操作，非常簡單。需要注意的是，由于執行一次CRUD操作后，Hibernate session關閉，如果有使用延遲加載策略的對象沒有加載，在后面的Web層很容易出現如下錯誤：
failed to lazily initialize a collection of role
從網上搜到的解決方法是Open Session In View，
<filter>
???? <filter-name>hibernateFilter</filter-name>
???? <filter-class> org.springframework.orm.hibernate3.support.OpenSessionInViewFilter
???? </filter-class>
???? <!-- singleSession默認為true,若設為false則等于沒用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>
我試了試，還是有一些問題，所以后來還是放棄了這種方法，所有在Web層中需要的對象都必須在Business層中加載完成。如下面的代碼所示：
ArrayList list = (ArrayList) this.getHibernateTemplate().find(
????"from Board b left join fetch b.Articles where b.Id = ? ", new Object[] { id });
這樣Hibernate和Spring的結合也算完成了。其他的一些DAO類和實現代碼我沒有給出，但是大同小異，和Board的實現類似。
最后將是Struts 和Spring的結合，將在下一篇給出。（未完待續）