struts2+hibernate4+spring3+maven搭建项目：简单账务管理系统第三篇：设计思路之model层，dao层，和service层

根据需求，数据库按照如下设计：

根据业务，表之间的关系如上图所示（hibernate可自动建表）。

本系统拟采用贫血模式设计，model层只有字段的内容，不包含数据库的操作方法，业务方法等。dao层只有sql文不包含业务，仅仅是根据数据表之间的关系，以可以想到的任何方式把对应model层的数据库中的内容取出，service层可以包含多个dao层，根据业务调用不同的dao层取出相应的内容，所谓业务，即任何与该Model有关的业务，不管是传入该Model作为参数还是得到该Model的实例或者List只要是跟该Model有关都是该Model的业务。不知道这样理解对不对，反正我就这么做啦，还是望大神们不吝赐教啊。

说这么多也没用，最重要的是上代码~~~

先看pojo和hibernate文件，找两个关系最简单地表，其他的依次类推，就比如goods表和goodsprice表

package com.medclub.pojo;

import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

public class GoodsPojo implements Serializable{

    @Override
    public String toString() {
        return "GoodsPojo [id=" + id + ", name=" + name + ", goodsPrices="
                + goodsPrices + "]";
    }
    private Integer id;
    private String name;
    //private Set<GoodsCommentPojo> goodsComments=new HashSet<GoodsCommentPojo>();
    private Set<GoodsPricePojo> goodsPrices=new HashSet<GoodsPricePojo>();
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
/*    public Set<GoodsCommentPojo> getGoodsComments() {
        return goodsComments;
    }
    public void setGoodsComments(Set<GoodsCommentPojo> goodsComments) {
        this.goodsComments = goodsComments;
    }*/
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        GoodsPojo other = (GoodsPojo) obj;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
    public Set<GoodsPricePojo> getGoodsPrices() {
        return goodsPrices;
    }
    public void setGoodsPrices(Set<GoodsPricePojo> goodsPrices) {
        this.goodsPrices = goodsPrices;
    }
    
}

package com.medclub.pojo;

import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

public class GoodsPricePojo implements Serializable{
    @Override
    public String toString() {
        return "GoodsPricePojo [id=" + id + ", price=" + price + ", goods="
                + goods + ", market=" + market + "]";
    }
    private Integer id;
    private Double price;
    private GoodsPojo goods;
    private MarketPojo market;
    private Set<OrderItemPojo> orderItems=new HashSet<OrderItemPojo>();
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public GoodsPojo getGoods() {
        return goods;
    }
    public void setGoods(GoodsPojo goods) {
        this.goods = goods;
    }
    public MarketPojo getMarket() {
        return market;
    }
    public void setMarket(MarketPojo market) {
        this.market = market;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((goods == null) ? 0 : goods.hashCode());
        result = prime * result + ((market == null) ? 0 : market.hashCode());
        return result;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        GoodsPricePojo other = (GoodsPricePojo) obj;
        if (goods == null) {
            if (other.goods != null)
                return false;
        } else if (!goods.equals(other.goods))
            return false;
        if (market == null) {
            if (other.market != null)
                return false;
        } else if (!market.equals(other.market))
            return false;
        return true;
    }
    public Double getPrice() {
        return price;
    }
    public void setPrice(Double price) {
        this.price = price;
    }
    public Set<OrderItemPojo> getOrderItems() {
        return orderItems;
    }
    public void setOrderItems(Set<OrderItemPojo> orderItems) {
        this.orderItems = orderItems;
    }
    
}

 <class entity-name="com.medclub.pojo.GoodsPojo" name="GoodsPojo" table="Goods">
  <id column="id" name="id">
   <generator class="identity"/>
  </id>
  <property generated="never" lazy="false"  name="name"/>
   <set lazy="false" inverse="true" name="goodsPrices" sort="unsorted">
   <key column="goods_id"/>
   <one-to-many class="GoodsPricePojo"/>
  </set>
 </class>
 <class entity-name="com.medclub.pojo.GoodsPricePojo" name="GoodsPricePojo" table="GoodsPrice">
 <id column="id" name="id">
 <generator class="identity"></generator>
</id>
<property generated="never" lazy="false"  name="price"/>
<many-to-one name="market" lazy="false"  column="market_id"/>
<many-to-one name="goods" lazy="false"  column="goods_id"/>
<set  lazy="false" inverse="true"  name="orderItems">
<key column="goodsprice_id"/>
<one-to-many class="OrderItemPojo"/>
</set>
 </class>

只是这两个Pojo的配置文件，因此就单独列出来，便于理解，其他的依次类推就好（不同的model层可以配置在不同的*.hbm.xml文件中此处不深究）。

然后是Dao层，Dao层的设计如下：

DAO接口是所有最基础的增删查改的方法的定义，其他的ModelDao接口继承该接口并拥有自己独立的方法；

BaseDao实现（implements）DAO接口，并继承(extends)SpringSessionContext（这个类操作事务提供数据库的Session）其他的ModelDaoImpl继承(extends)这个BaseDao并实现（implements）自己的接口,如ModelDao

说这么多还是举例子最靠谱，是上面GoodsPojo和GoodsPrice对应的Dao层：

package com.medclub.dao;

import java.io.Serializable;
import java.util.List;

public interface DAO{
public Object getObject(Class clazz,Serializable id);
public List getObjectList(Class clazz);
public void saveObject(Object obj);
public void deleteObject(Class clazz,Serializable id);
public List getObjectListByExample(Object example);
public void saveOrUpdateObject(Object obj);
public List getByExampleLike(Object example);
public void save(Object obj);
}

package com.medclub.dao;

import java.io.Serializable;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.criterion.MatchMode;
import org.hibernate.criterion.Restrictions;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.springframework.orm.ObjectRetrievalFailureException;
import org.springframework.orm.hibernate4.SpringSessionContext;
import org.hibernate.Criteria;

import com.kc.reign.util.ReflectHelper;
import com.medclub.pojo.DepartmentPojo;


public class BaseDao<T extends Serializable,PK extends Serializable> extends SpringSessionContext implements DAO{
    public BaseDao(SessionFactoryImplementor sessionFactory) {
        super(sessionFactory);
        // TODO Auto-generated constructor stub
    }
    protected ReflectHelper helper;
    public ReflectHelper getHelper() {
        return helper;
    }


    public void setHelper(ReflectHelper helper) {
        this.helper = helper;
    }


    public Object getObject(Class clazz, Serializable id) {
        // TODO Auto-generated method stub
    Object o= getHibernateTemplate().get(clazz, id);
    if(o==null){
        throw new ObjectRetrievalFailureException(clazz,id);
    }
    return o;
    }


    protected Session getHibernateTemplate() {
        // TODO Auto-generated method stub
        return currentSession();
    }


    public List<T> getObjectList(Class clazz) {
        // TODO Auto-generated method stub

        return getHibernateTemplate().createQuery("from "+clazz.getName()).list();
    }

    public void saveObject(Object obj) {
        // TODO Auto-generated method stub
        getHibernateTemplate().save(obj);
    }

    public void deleteObject(Class clazz, Serializable id) {
        // TODO Auto-generated method stub
        getHibernateTemplate().delete(getObject(clazz, id));
    }
    public List<T> getObjectListByExample(Object example){
        Map<String,Object> objmap=helper.getMapFromObj(example);
        return getHibernateTemplate().createCriteria(example.getClass()).add(Restrictions.allEq(objmap)).list();
    }


    public void saveOrUpdateObject(Object obj) {
        // TODO Auto-generated method stub
        getHibernateTemplate().saveOrUpdate(obj);
    }

    public void save(Object obj){
        getHibernateTemplate().save(obj);
    }
    public List<T> getByExampleLike(Object example) {
        // TODO Auto-generated method stub
        Map<String,Object> objmap=helper.getMapFromObj(example);
        Criteria criteria=getHibernateTemplate().createCriteria(example.getClass());
           Set<Entry<String, Object>> entries=objmap.entrySet();
           if(entries!=null)
           {
               Iterator<Entry<String, Object>> it=entries.iterator();
               while(it.hasNext())
               {
                   Map.Entry<String,Object> entry=(Entry<String, Object>) it.next();
                   if(entry.getKey()!=null&&entry.getValue()!=null)
                   {
                       if(!entry.getValue().toString().trim().equals("")){
                           criteria.add(Restrictions.ilike(entry.getKey(),(String)entry.getValue(),MatchMode.ANYWHERE));
                       }
                   }
               }
           }
        return criteria.list(); 
    }

}

package com.medclub.tests.dao;

import java.util.Date;
import java.util.List;

import com.medclub.dao.DAO;
import com.medclub.pojo.GoodsPojo;
import com.medclub.pojo.GoodsPricePojo;

public interface GoodsDao extends DAO{
    public List<GoodsPojo> getByNameLike(String name);
}

package com.medclub.tests.dao;

import java.util.Date;
import java.util.List;

import com.medclub.dao.DAO;
import com.medclub.pojo.GoodsCarPojo;
import com.medclub.pojo.GoodsPojo;
import com.medclub.pojo.GoodsPricePojo;
import com.medclub.pojo.MarketPojo;
import com.medclub.pojo.OrderItemPojo;

public interface GoodsPriceDao extends DAO{
    
    public List<GoodsPricePojo> getByGoods(GoodsPojo pojo);//通过商品得到商品对应单价
    public List<GoodsPricePojo> getByMarket(MarketPojo pojo);//通过超市得到超市对应的所有单价
    public List<GoodsPricePojo> getOneByGoodsAndMarket(GoodsPojo goods,MarketPojo market);//通过商品和超市得到具体的商品单价
    public GoodsPricePojo getTheLowestPriceByGoods(GoodsPojo goods);//通过商品得到最低单价（未实现！）
}

package com.medclub.tests.daoimpl;

import java.util.Date;
import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.engine.spi.SessionFactoryImplementor;

import com.medclub.dao.BaseDao;
import com.medclub.pojo.GoodsCarPojo;
import com.medclub.pojo.GoodsPojo;
import com.medclub.pojo.GoodsPricePojo;
import com.medclub.tests.dao.GoodsDao;

public class GoodsDaoImpl extends BaseDao<GoodsPojo,Integer> implements GoodsDao{

    public GoodsDaoImpl(SessionFactoryImplementor sessionFactory) {
        super(sessionFactory);//sessionFactory：注入
        // TODO Auto-generated constructor stub
    }
               //通过商品名称得到商品
    public List<GoodsPojo> getByNameLike(String name) {
        // TODO Auto-generated method stub
        GoodsPojo goods=new GoodsPojo();
        goods.setName(name);
        return getByExampleLike(goods);//通过Like得到List
    }


}

package com.medclub.tests.daoimpl;

import java.util.List;

import org.hibernate.Query;
import org.hibernate.engine.spi.SessionFactoryImplementor;

import com.medclub.dao.BaseDao;
import com.medclub.pojo.GoodsCarPojo;
import com.medclub.pojo.GoodsPojo;
import com.medclub.pojo.GoodsPricePojo;
import com.medclub.pojo.MarketPojo;
import com.medclub.pojo.OrderItemPojo;
import com.medclub.tests.dao.GoodsPriceDao;

public class GoodsPriceDaoImpl extends BaseDao<GoodsPricePojo,Integer> implements GoodsPriceDao{
    private final String HQL="from GoodsPricePojo as g";
    public GoodsPriceDaoImpl(SessionFactoryImplementor sessionFactory) {
        super(sessionFactory);
        // TODO Auto-generated constructor stub
    }

    public List<GoodsPricePojo> getByGoods(GoodsPojo pojo) {
        // TODO Auto-generated method 
        Integer goodsid=pojo.getId();
        StringBuffer hql=new StringBuffer(HQL);
        hql.append(" where g.goods.id=:goodsid");//单价与商品：多对一，由单价来维护与商品之间的关系
        Query q=getHibernateTemplate().createQuery(hql.toString());
        q.setParameter("goodsid",goodsid);
        return q.list();
    }

    public List<GoodsPricePojo> getByMarket(MarketPojo pojo) {
        // TODO Auto-generated method stub
        Integer marketid=pojo.getId();
        StringBuffer hql=new StringBuffer(HQL);
        hql.append(" where g.market.id=:marketid");
//单价与超市：一对多，由单价 维护与超市之间的关系        
Query q=getHibernateTemplate().createQuery(hql.toString());
        q.setParameter("marketid",marketid);
        return q.list();
    }

    public List<GoodsPricePojo> getOneByGoodsAndMarket(GoodsPojo goods,
            MarketPojo market) {
        // TODO Auto-generated method stub
        Integer marketid=market.getId();
        Integer goodsid=goods.getId();
        StringBuffer hql=new StringBuffer(HQL);
        hql.append(" where g.goods.id=:goodsid and g.market.id=:marketid");
        Query q=getHibernateTemplate().createQuery(hql.toString());
        q.setParameter("goodsid",goodsid);
        q.setParameter("marketid", marketid);
        return q.list();
    }

//    public List<GoodsPricePojo> getByOrderItem(OrderItemPojo order) {
//        // TODO Auto-generated method stub
//        return null;
//    }

//    public List<GoodsPricePojo> getByGoodsCar(GoodsCarPojo goodsCar) {
//        // TODO Auto-generated method stub
//        Integer goodscarid=goodsCar.getId();
//        StringBuffer hql=new StringBuffer(HQL);
//        hql.append(" where g.goodscar.id=:goodscarid");
//        return null;
//    }
                //未实现，也没用到
    public GoodsPricePojo getTheLowestPriceByGoods(GoodsPojo goods) {
        // TODO Auto-generated method stub
        return null;
    }


}

泛型的话，是因为在类加载前加载父类时就初始化Model的实例，对性能比较好，而且可以对BaseDao中的返回值进行处理，不用返回Object再强转，这只是我浅薄的理解，具体的望大神们不吝赐教！

不过貌似大神们都是来看热闹的哎，，，好吧，我献丑啦

接下来是最后的Service层，在Service-Context.xml中配置Service层的组件，依然是先接口再实例，spring的代理之前讲过，是先JDK代理再CGLIB，即配置文件中是实体类，引用的时候引用接口，此处就提一下，不深究啦。配置文件以及例子（还是Goods和GoodsPrice）如下：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
"http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="goodsService" class="com.medclub.service.impl.GoodsServiceImpl">
<property name="daoGoods"><ref bean="goodsDao"/></property>
<property name="daoGoodsPrice"><ref bean="goodsPriceDao"/></property>
</bean>
<bean id="goodsPriceService" class="com.medclub.service.impl.GoodsPriceServiceImpl">
<property name="daoGoodsPrice"><ref bean="goodsPriceDao"/></property>
</bean>
</beans>

package com.medclub.service;

import java.util.Date;
import java.util.List;

import com.medclub.pojo.GoodsCarPojo;
import com.medclub.pojo.GoodsPojo;
import com.medclub.pojo.GoodsPricePojo;
import com.medclub.pojo.MarketPojo;

public interface GoodsService {
public void saveOrUpdateGoods(GoodsPojo goods);//保存或者更新商品
public List<GoodsPojo> getAllGoods();//得到所有的商品
public List<GoodsPojo> getNameSpecifiedGoods(String name);//通过商品名的到商品
public List<GoodsPricePojo> getGoodsPricesByGoods(GoodsPojo goods);//通过商品得到商品单价
public void DeleteGoods(GoodsPojo goods);//删除商品
public List<GoodsPojo> getByExample(GoodsPojo goods);//通过实体得到列表

}

package com.medclub.service;



import java.util.List;

import com.medclub.pojo.GoodsPojo;
import com.medclub.pojo.GoodsPricePojo;
import com.medclub.pojo.MarketPojo;

public interface GoodsPriceService {
    public void SaveOrUpdateGoodsPrice(GoodsPricePojo goodsPrice);
    public void deleteGoodsPrice(GoodsPricePojo goodsPrice);
    public List<GoodsPricePojo> getByMarket(MarketPojo market);
    public List<GoodsPricePojo> getByGoods(GoodsPojo goods);
    public List<GoodsPricePojo> getByGoodsAndMarket(GoodsPojo goods,MarketPojo market);
    public List<GoodsPricePojo> getAllPrices();
}

package com.medclub.service.impl;

import java.util.List;

import com.medclub.pojo.GoodsPojo;
import com.medclub.pojo.GoodsPricePojo;
import com.medclub.pojo.MarketPojo;
import com.medclub.service.GoodsService;
import com.medclub.tests.dao.GoodsDao;
import com.medclub.tests.dao.GoodsPriceDao;

public class GoodsServiceImpl implements GoodsService{

    private GoodsDao daoGoods;//商品Dao注入
    private GoodsPriceDao daoGoodsPrice;//商品单价Dao注入
             /*保存商品*/
    public void saveOrUpdateGoods(GoodsPojo goods) {
        // TODO Auto-generated method stub
        daoGoods.saveOrUpdateObject(goods);
    }
               /*得到所有商品*/
    public List<GoodsPojo> getAllGoods() {
        // TODO Auto-generated method stub
        return daoGoods.getObjectList(GoodsPojo.class);
    }
                /*通过名字得到商品*/
    public List<GoodsPojo> getNameSpecifiedGoods(String name) {
        // TODO Auto-generated method stub
        return daoGoods.getByNameLike(name);
    }
               /*通过超市得到商品列表*/
    public List<GoodsPojo> getGoodsByMarket(MarketPojo market) {
        // TODO Auto-generated method stub
        return null;
    }
                /*删除商品*/
    public void DeleteGoods(GoodsPojo goods) {
        // TODO Auto-generated method stub
        daoGoods.deleteObject(GoodsPojo.class,goods.getId());
    }
                 /*注入商品dao*/
    public GoodsDao getDaoGoods() {
        return daoGoods;
    }

    public void setDaoGoods(GoodsDao daoGoods) {
        this.daoGoods = daoGoods;
    }
                /*通过商品得到单价*/

    public List<GoodsPricePojo> getGoodsPricesByGoods(GoodsPojo goods) {
        // TODO Auto-generated method stub
        return daoGoodsPrice.getByGoods(goods);
    }
                 /*通过例子得到商品列表*/

    public List<GoodsPojo> getByExample(GoodsPojo goods) {
        // TODO Auto-generated method stub
        return daoGoods.getObjectListByExample(goods);
    }
                 /*注入单价Dao*/
    public GoodsPriceDao getDaoGoodsPrice() {
        return daoGoodsPrice;
    }

    public void setDaoGoodsPrice(GoodsPriceDao daoGoodsPrice) {
        this.daoGoodsPrice = daoGoodsPrice;
    }
}

package com.medclub.service.impl;

import java.util.List;

import com.medclub.pojo.GoodsPojo;
import com.medclub.pojo.GoodsPricePojo;
import com.medclub.pojo.MarketPojo;
import com.medclub.service.GoodsPriceService;
import com.medclub.tests.dao.GoodsPriceDao;

public class GoodsPriceServiceImpl implements GoodsPriceService{
    private GoodsPriceDao daoGoodsPrice;//注入单价dao
                //保存或者更新单价
    public void SaveOrUpdateGoodsPrice(GoodsPricePojo goodsPrice) {
        // TODO Auto-generated method stub
        daoGoodsPrice.saveOrUpdateObject(goodsPrice);
    }
               //删除单价
    public void deleteGoodsPrice(GoodsPricePojo goodsPrice) {
        // TODO Auto-generated method stub
        daoGoodsPrice.deleteObject(GoodsPricePojo.class, goodsPrice.getId());
    }
                //注入单价dao
    public GoodsPriceDao getDaoGoodsPrice() {
        return daoGoodsPrice;
    }

    public void setDaoGoodsPrice(GoodsPriceDao daoGoodsPriceDao) {
        this.daoGoodsPrice = daoGoodsPriceDao;
    }
               //通过超市得到所有单价
    public List<GoodsPricePojo> getByMarket(MarketPojo market) {
        // TODO Auto-generated method stub
        return daoGoodsPrice.getByMarket(market);
    }
               //通过商品得到单价
    public List<GoodsPricePojo> getByGoods(GoodsPojo goods) {
        // TODO Auto-generated method stub
        return daoGoodsPrice.getByGoods(goods);
    }
                 //通过商品和超市得到单价
    public List<GoodsPricePojo> getByGoodsAndMarket(GoodsPojo goods,
            MarketPojo market) {
        // TODO Auto-generated method stub
        return daoGoodsPrice.getOneByGoodsAndMarket(goods, market);
    }
               //得到所有单价
    public List<GoodsPricePojo> getAllPrices() {
        // TODO Auto-generated method stub
        return daoGoodsPrice.getObjectList(GoodsPricePojo.class);
    }

}

恩，这一篇就写到这里吧，后面再总结action和jsp表现层部分