struts+hibernate+spring分页的简单实现(一)

今天终于实现了hibernate实现分页了。。把oksonic的SSH的例子做了增加，实现了查询的分页。

同时现在也把srtuts + spring + hibernate  结合的实现方法重新复习了一下，总结如下：

1  首先肯定是要把对应的数据库的表进行映射的，把影射类和表的映射XML文件放到包bo中：

    包含文件AbstractUser.java        User.java        User.hbm.xml

    表的映射配置文件如下：

<hibernate-mapping>    <class name="com.oa.data.bo.User" table="userlist">        <id name="id" type="integer">            <column name="id" />            <generator class="native"></generator>        </id>        <property name="userName" type="string">            <column name="userName" length="100" not-null="true" />        </property>        <property name="userPwd" type="string">            <column name="userPwd" length="100" not-null="true" />        </property>    </class></hibernate-mapping>

2  写DAO数据访问接口IUserDAO .java，放在dao包中：

package com.oa.data.dao;

import java.util.List;

import com.oa.data.bo.User;

public interface IUserDAO {

public abstract void save(User transientInstance);

 public abstract void delete(User persistentInstance);

 public abstract User findById(java.lang.Integer id);

 public abstract List findByExample(User instance);

 public abstract User merge(User detachedInstance);

 public abstract void attachDirty(User instance);

 public abstract void attachClean(User instance);  public abstract User findByUsername(String username);  public List findWithPage(int pageSize, int startRow);  public int counter();

}

3   写DAO数据访问实现类 UserDAO .java，放在dao.imp包中：

package com.oa.data.dao.impl;

import java.util.ArrayList;import java.util.List;

import net.sf.hibernate.Transaction;

import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.hibernate.LockMode;import org.hibernate.criterion.Example;import org.springframework.context.ApplicationContext;import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import com.oa.data.bo.User;import com.oa.data.dao.IUserDAO;

/** * Data access object (DAO) for domain model class User. * @see .User * @author MyEclipse - Hibernate Tools */public class UserDAO extends HibernateDaoSupport implements IUserDAO {

    private static final Log log = LogFactory.getLog(UserDAO.class);

 protected void initDao() {  //do nothing }        /* (non-Javadoc)  * @see com.oa.data.dao.impl.IUserDAO#save(com.oa.data.bo.User)  */    public void save(User transientInstance) {        log.debug("saving User instance");        try {         this.getHibernateTemplate().saveOrUpdate(transientInstance);            log.debug("save successful");        } catch (RuntimeException re) {            log.error("save failed", re);            throw re;        }    }     /* (non-Javadoc)  * @see com.oa.data.dao.impl.IUserDAO#delete(com.oa.data.bo.User)  */ public void delete(User persistentInstance) {        log.debug("deleting User instance");        try {            getHibernateTemplate().delete(persistentInstance);            log.debug("delete successful");        } catch (RuntimeException re) {            log.error("delete failed", re);            throw re;        }    }        /* (non-Javadoc)  * @see com.oa.data.dao.impl.IUserDAO#findById(java.lang.Integer)  */    public User findById( java.lang.Integer id) {        log.debug("getting User instance with id: " + id);        try {            User instance = (User) getHibernateTemplate()                    .get("User", id);            return instance;        } catch (RuntimeException re) {            log.error("get failed", re);            throw re;        }    }            /* (non-Javadoc)  * @see com.oa.data.dao.impl.IUserDAO#findByExample(com.oa.data.bo.User)  */    public List findByExample(User instance) {        log.debug("finding User instance by example");        try {            List results = getSession()                    .createCriteria("User")                    .add(Example.create(instance))            .list();            log.debug("find by example successful, result size: " + results.size());            return results;        } catch (RuntimeException re) {            log.error("find by example failed", re);            throw re;        }    }            /* (non-Javadoc)  * @see com.oa.data.dao.impl.IUserDAO#merge(com.oa.data.bo.User)  */    public User merge(User detachedInstance) {        log.debug("merging User instance");        try {            User result = (User) getHibernateTemplate()                    .merge(detachedInstance);            log.debug("merge successful");            return result;        } catch (RuntimeException re) {            log.error("merge failed", re);            throw re;        }    }

    /* (non-Javadoc)  * @see com.oa.data.dao.impl.IUserDAO#attachDirty(com.oa.data.bo.User)  */    public void attachDirty(User instance) {        log.debug("attaching dirty User instance");        try {            getHibernateTemplate().saveOrUpdate(instance);            log.debug("attach successful");        } catch (RuntimeException re) {            log.error("attach failed", re);            throw re;        }    }        /* (non-Javadoc)  * @see com.oa.data.dao.impl.IUserDAO#attachClean(com.oa.data.bo.User)  */    public void attachClean(User instance) {        log.debug("attaching clean User instance");        try {            getHibernateTemplate().lock(instance, LockMode.NONE);            log.debug("attach successful");        } catch (RuntimeException re) {            log.error("attach failed", re);            throw re;        }    }

 public static IUserDAO getFromApplicationContext(ApplicationContext ctx) {     return (IUserDAO) ctx.getBean("UserDAO"); }

 public User findByUsername(String username) {  log.debug("getting User instance with userName: " + username);  try {   List list = getHibernateTemplate().find(     "from User as u where userName = ?", username);   if(list.size() > 0) {    User instance = (User) list.get(0);    return instance;   } else {    return null;   }  } catch (RuntimeException re) {   log.error("get failed", re);   throw re;  } }

 public List findWithPage(int pageSize, int startRow) {  List list=new ArrayList();  Transaction tx = null;   log.debug("ShowAllUser");  try {   org.hibernate.Query q ;   q=this.getSessionFactory().openSession().createQuery("from User");   q.setFirstResult(startRow);   q.setMaxResults(pageSize);                                                 //  hibernate简单分页的设置，设置起始行和每页的记录数   list=q.list();     } catch (RuntimeException e) {   // TODO Auto-generated catch block          e.printStackTrace();  }    return list; }

 public int counter() {  int counter=0;  Transaction tx = null;   log.debug("counter");  counter = ((Integer)this.getHibernateTemplate().iterate("select count(*) from User").next()).intValue();   return counter; }}

4  因为用到了spring，需要做DAO服务代理，所以有必要实现服务类。service包中：

package com.oa.model.service;

import java.util.List;

import com.oa.data.bo.User;

public interface IUserService {//  验证用户是否合法，并返回一个 User 对像     public User isValidUser(String username,String password);     public List findWithPage(int pageSize, int startRow);      public int counter();}

5  有服务接口就有实现类：service.imp包中：

package com.oa.model.service.impl;

import java.util.ArrayList;import java.util.List;

import com.oa.data.bo.User;import com.oa.data.dao.IUserDAO;import com.oa.model.service.IUserService;

public class UserService implements IUserService {

 private IUserDAO userDAO;  public IUserDAO getUserDAO() {  return userDAO; }

 public void setUserDAO(IUserDAO userDAO) {  this.userDAO = userDAO; }

 public User isValidUser(String username, String password) {  // TODO Auto-generated method stub  User user = userDAO.findByUsername(username);  if(user == null)   return null;  if(user.getUserPwd().equals(password))   return user;  return null; }

 public List findWithPage(int pageSize, int startRow) {  // TODO Auto-generated method stub  ArrayList list=new ArrayList();  list=(ArrayList) userDAO.findWithPage(pageSize,startRow);  return list; }

 public int counter() {  // TODO Auto-generated method stub  int counter=0;  counter=userDAO.counter();  return counter; }

}