struts+spring+hibernate的web使用<二> Dao层代码编写

struts+spring+hibernate的web应用<二> Dao层代码编写

前一篇文章(struts+spring+hibernate的web应用<一>? 架构搭建)让我们打好了架子，接下来就来编写代码了。在编码之前，我们需要先自行了解strust,spring,hibernate基础知识，后面的文章将不会过多的介绍这些框架的基础知识。整个项目由Dao,Services,Web三层组成，Dao层主要通过hibernate来操作数据库，Service层主要体现了业务，事务的处理，Web层由struts来控制。整个项目的控制交由spring管理。

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现在的这个小项目除了完成基本的添删改查，还有一个简单的分页功能。这个分页功能不仅前台分页，而且在后台数据库也进行了分页处理。

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现在就来编写Dao层的代码。

首先写好pojo的代码：

在com.game.products.model中新建products.hbm.xml类，代码如下：

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<?xml?version="1.0"?encoding="GB2312"?>
<!DOCTYPE?hibernate-mapping?PUBLIC?"-//Hibernate/Hibernate?Mapping?DTD?3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
?????<class?name="com.game.products.model.Products"?table="products"?>
?????????<id?name="gameId"?type="string">
????????????<column?name="game_id"?length="5"?/>
????????????<generator?class="assigned"?/>
????????</id>
????????<property?name="gameNameCn"?type="string">
????????????<column?name="game_name_cn"?length="100"?/>
????????</property>
?????????<property?name="gameNameEn"?type="string">
????????????<column?name="game_name_en"?length="100"?/>
????????</property>
????????<property?name="gameCapacity"?type="string">
????????????<column?name="game_capacity"?length="4"?/>
????????</property>
?????????<property?name="gameVersion"?type="string">
????????????<column?name="game_version"?length="4"?/>
????????</property>
??????????<property?name="gameMedia"?type="string">
????????????<column?name="game_media"?length="4"?/>
????????</property>
????????<property?name="gameCopyright"?type="string">
????????????<column?name="game_copyright"?length="4"?/>
????????</property>
????????<property?name="gamePrice"?type="string">
????????????<column?name="game_price"?length="4"?/>
????????</property>?
?????????<property?name="gameContent"?type="string">
????????????<column?name="game_content"?length="100"?/>
????????</property>
?????</class>
</hibernate-mapping>

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注意这里的ID不是数据库自动生成的，而是根据需要由程序生成，一般项目中的主键ID都是采取这种方式。

然后在这个包中再新建Products类，代码如下：

package?com.game.products.model;

public?class?Products?{
????//????Fields?
????private?String?gameId;//编号
????private?String?gameNameCn;//中文名称
????private?String?gameNameEn;//英文名称
????private?String?gameCapacity;//碟数
????private?String?gameVersion;//版本
????private?String?gameMedia;//介质
????private?String?gameCopyright;//版权
????private?String?gamePrice;//价格
????private?String?gameContent;//攻略
????
????//????Constructors
????public?Products(){}
????
????//????Property?accessors
????public?String?getGameCapacity()?{
????????return?gameCapacity;
????}

????public?void?setGameCapacity(String?gameCapacity)?{
????????this.gameCapacity?=?gameCapacity;
????}

????public?String?getGameId()?{
????????return?gameId;
????}

????public?void?setGameId(String?gameId)?{
????????this.gameId?=?gameId;
????}

????public?String?getGameNameCn()?{
????????return?gameNameCn;
????}

????public?void?setGameNameCn(String?gameNameCn)?{
????????this.gameNameCn?=?gameNameCn;
????}

????public?String?getGameNameEn()?{
????????return?gameNameEn;
????}

????public?void?setGameNameEn(String?gameNameEn)?{
????????this.gameNameEn?=?gameNameEn;
????}

????public?String?getGameVersion()?{
????????return?gameVersion;
????}

????public?void?setGameVersion(String?gameVersion)?{
????????this.gameVersion?=?gameVersion;
????}

????public?String?getGameMedia()?{
????????return?gameMedia;
????}

????public?void?setGameMedia(String?gameMedia)?{
????????this.gameMedia?=?gameMedia;
????}

????public?String?getGameCopyright()?{
????????return?gameCopyright;
????}

????public?void?setGameCopyright(String?gameCopyright)?{
????????this.gameCopyright?=?gameCopyright;
????}

????public?String?getGameContent()?{
????????return?gameContent;
????}

????public?void?setGameContent(String?gameContent)?{
????????this.gameContent?=?gameContent;
????}

????public?String?getGamePrice()?{
????????return?gamePrice;
????}

????public?void?setGamePrice(String?gamePrice)?{
????????this.gamePrice?=?gamePrice;
????}

}

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需要注意的是，我这里都是采用了string类型，因为在项目中传递数据，用string类型最为方便，同时也便于代码的编写。只是在前台需要编写验证代码，免得有字符数据插入整数字段而造成数据库异常。

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在com.game.products.dao.iface包中新建ProductsDao接口。

代码如下所示：

package?com.game.products.dao.iface;

import?java.util.List;

import?com.game.products.model.Products;

public?interface?ProductsDao?{
????List?getProducts();//获得所有记录
????List?getProducts(int?pageSize,?int?startRow);//获得一段记录
????int?getRows();//获得总行数
????int?getRows(String?fieldname,String?value);//获得总行数
????List?queryProducts(String?fieldname,String?value);//根据条件查询的所有记录
????List?queryProducts(String?fieldname,String?value,int?pageSize,?int?startRow);//根据条件查询的一段记录
????Products?getProduct(String?gameId);//根据ID获得记录
????String?getMaxID();//获得最大ID值
????void?addProduct(Products?pd);//添加记录
????void?updateProductd(Products?pd);//修改记录
????void?deleteProduct(Products?pd);//删除记录????
}

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在com.game.products.dao.hibernate包中新建继承HibernateDaoSupport的ProductsMapDao类，并实现了ProductsDao接口。

代码如下：

package?com.game.products.dao.hibernate;

import?java.sql.SQLException;
import?java.util.Iterator;
import?java.util.List;

import?org.hibernate.HibernateException;
import?org.hibernate.Query;
import?org.hibernate.Session;
import?org.springframework.orm.hibernate3.HibernateCallback;
import?org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import?com.game.products.dao.iface.ProductsDao;
import?com.game.products.model.Products;


/**
?*?@author?cwf
?*
?*/
public?class?ProductsMapDao?extends?HibernateDaoSupport?implements?ProductsDao?{

????public?ProductsMapDao(){}

????/**
?????*?函数说明：添加信息
?????*?参数说明：对象?
?????*?返回值：
?????*/
????public?void?addProduct(Products?pd)?{
????????this.getHibernateTemplate().save(pd);
????}

????/**
?????*?函数说明：删除信息
?????*?参数说明：?对象
?????*?返回值：
?????*/
????public?void?deleteProduct(Products?pd)?{
????????this.getHibernateTemplate().delete(pd);
????}

????/**
?????*?函数说明：获得所有的信息
?????*?参数说明：?
?????*?返回值：信息的集合
?????*/
????public?List?getProducts()?{
????????String?sql="FROM?Products?ORDER?BY?gameNameCn";
????????return?this.getHibernateTemplate().find(sql);
????}
????
????/**
?????*?函数说明：获得总行数
?????*?参数说明：?
?????*?返回值：总行数
?????*/
????public?int?getRows()?{
????????String?sql="FROM?Products?ORDER?BY?gameNameCn";
????????List?list=this.getHibernateTemplate().find(sql);
????????return?list.size();
????}
????
????/**
?????*?函数说明：获得一段记录信息
?????*?参数说明：?
?????*?返回值：信息的集合
?????*/
????public?List?getProducts(int?pageSize,?int?startRow)?throws?HibernateException?{
????????final?int?pageSize1=pageSize;
????????final?int?startRow1=startRow;
????????return?this.getHibernateTemplate().executeFind(new?HibernateCallback(){

????????????public?List?doInHibernate(Session?session)?throws?HibernateException,?SQLException?{
????????????????Query?query=session.createQuery("FROM?Products?ORDER?BY?gameNameCn");
????????????????query.setFirstResult(startRow1);
????????????????query.setMaxResults(pageSize1);
????????????????return?query.list();
????????????}
????????});
????}

????/**
?????*?函数说明：获得一条的信息
?????*?参数说明：?ID
?????*?返回值：对象
?????*/
????public?Products?getProduct(String?gameId)?{
????????return?(Products)this.getHibernateTemplate().get(Products.class,gameId);
????}

????/**
?????*?函数说明：获得最大ID
?????*?参数说明：?
?????*?返回值：最大ID
?????*/
????public?String?getMaxID()?{
????????String?sql="SELECT?MAX(gameId)+1?FROM?Products??";
????????String?noStr?=?null;
????????List?ll?=?(List)?this.getHibernateTemplate().find(sql);
????????Iterator?itr?=?ll.iterator();
????????if?(itr.hasNext())?{
????????????Object?noint?=?itr.next();
????????????if(noint?==?null){
????????????????noStr?=?"1";????????????????
????????????}else{
????????????????noStr?=?noint.toString();
????????????}
????????}
????????
????????if(noStr.length()==1){
????????????noStr="000"+noStr;
????????}else?if(noStr.length()==2){
????????????noStr="00"+noStr;
????????}else?if(noStr.length()==3){
????????????noStr="0"+noStr;
????????}else{
????????????noStr=noStr;
????????}
????????return?noStr;
????}

????/**
?????*?函数说明：修改信息
?????*?参数说明：?对象
?????*?返回值：
?????*/
????public?void?updateProductd(Products?pd)?{
????????this.getHibernateTemplate().update(pd);
????}

????/**
?????*?函数说明：查询的所有信息
?????*?参数说明：?集合
?????*?返回值：
?????*/
????public?List?queryProducts(String?fieldname,String?value)?{
????????System.out.println("value:?"+value);
????????String?sql="FROM?Products?where?"+fieldname+"?like?'%"+value+"%'"+"ORDER?BY?gameNameCn";
????????return?this.getHibernateTemplate().find(sql);
????}
????
????/**
?????*?函数说明：获得总行数
?????*?参数说明：?
?????*?返回值：总行数
?????*/
????public?int?getRows(String?fieldname,String?value)?{
????????String?sql="FROM?Products?where?"+fieldname+"?like?'%"+value+"%'"+"ORDER?BY?gameNameCn";
????????List?list=this.getHibernateTemplate().find(sql);
????????return?list.size();
????}
????
????/**
?????*?函数说明：查询的一段信息
?????*?参数说明：?集合
?????*?返回值：
?????*/
????public?List?queryProducts(String?fieldname,String?value,int?pageSize,?int?startRow)?{
????????final?int?pageSize1=pageSize;
????????final?int?startRow1=startRow;
????????final?String?sql="FROM?Products?where?"+fieldname+"?like?'%"+value+"%'"+"ORDER?BY?gameNameCn";
????????return?this.getHibernateTemplate().executeFind(new?HibernateCallback(){

????????????public?List?doInHibernate(Session?session)?throws?HibernateException,?SQLException?{
????????????????Query?query=session.createQuery(sql);
????????????????query.setFirstResult(startRow1);
????????????????query.setMaxResults(pageSize1);
????????????????return?query.list();
????????????}
????????});
????}

}

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在com.game.bean.hibernate包中新建hibernate.cfg.xml，代码如下：

<?xml?version="1.0"?encoding="GB2312"?>
<!DOCTYPE?hibernate-configuration?PUBLIC
????"-//Hibernate/Hibernate?Configuration?DTD?3.0//EN"
????"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
????<session-factory>
????????<property?name="dialect">org.hibernate.dialect.SQLServerDialect</property>
????????<property?name="show_sql">true</property>

????????<mapping?resource="com/game/products/model/products.hbm.xml"></mapping>
????</session-factory>
</hibernate-configuration>

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至此，DAO层的代码已经编写完成。下一篇，将编写service层代码。

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