搭建ssh后的简化
对于SSh框架的简化，我们可以从下面几个方面来剖析：
1、实体类entity
2.注入
3.类注解
下面，我来一一为大家讲解。ps:写的不好还请多多指教，欢迎大家”来找茬“。
关于实体类的简化，我们一般是将.hbm.xml文件删除，然后配着注解来实现简化，下面我们举一个简单的例子来体验实体类的简化给我们带来的便利
如下:
以前我们需要编写实体类.hbm.xml来完成映射
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="news.entity"> <class name="News" table="news"> <id name="id"> <generator class="increment"/> </id> <property name="title" type="string" length="50" column="title" not-null="true"></property> <property name="content"></property> <property name="begintime"></property> <property name="usename"></property> </class> </hibernate-mapping>
而现在，我们用了注解就不需要了，代码如下：
package news.entity; import java.util.Date; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.Table; /** * @author Administrator * */ @Entity @Table(name="news")//这里的name对应的是数据库那边的表名 public class News { private Integer id; private String title; private String content; private Date begintime; private String usename; @Id @GeneratedValue(strategy = GenerationType.AUTO)public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } @Column public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } @Column public String getContent() { return content; } public void setContent(String content) { this.content = content; } @Column public Date getBegintime() { return begintime; } public void setBegintime(Date begintime) { this.begintime = begintime; } @Column public String getUsename() { return usename; } public void setUsename(String usename) { this.usename = usename; } }
接下来我们来看注入。
对于注入的简化，我的理解就是不需要new，把它交给spring去完成
而在这之前，我们都是定义一个私有属性，并给他设置set方法，然后在applicationContext.xml中设置如下
<bean id="newsAction" class="news.action.NewsAction"> <property name="ns" ref="myNewsService"/> </bean> <bean id="myNewsService"class="news.service.NewsServiceImpl"> <property name="nd" ref="myNewsDao"/> </bean> <bean id="myNewsDao" class="news.dao.NewsDaoImpl"> <property name="sf" ref="sessionFactory"></property> </bean>
然而我们用上注解的话，applicationContext.xml文件就变成了这样
<bean id="newsAction" class="news.action.NewsAction"/> <bean id="myNewsService"class="news.service.NewsServiceImpl"/> <bean id="myNewsDao" class="news.dao.NewsDaoImpl"/>
删除完映射文件，我们还需要在applicationContext.xml里面配置，如下：
这样才能知道她找到对应的实体类
当然我们所对应的Action,dao.service类都需要加上注解，如下：
package news.action; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import com.opensymphony.xwork2.ActionSupport; import news.entity.News; import news.service.NewsService; public class NewsAction extends ActionSupport { //@Resource(name="myNewsService") 这是jdk自带注解 @Autowired @Qualifier//这两个是spring的注解 private NewsService ns; private List<News> listAll; private Integer id; private String message; public List<News> getListAll() { return listAll; } public void setId(Integer id) { this.id = id; } public Integer getId() { return id; } public String getMessage() { return message; } public void setMessage(String message) { this.message = message; } public String showAll(){ listAll=ns.showAll(); // System.out.println(ns); return "success"; } public String deleteSingleNews(){ message=ns.deleteSingleNews(id); return message; } }
package news.dao; import java.util.List; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.query.Query; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import news.entity.News; public class NewsDaoImpl implements NewsDao { //@Resource(name="sessionFactory") @Autowired @Qualifier private SessionFactory sf; public List<News> showAll(){ Session session =sf.openSession(); //Session session=sf.getCurrentSession(); Query query=session.createQuery("from News"); List<News> listAll=query.getResultList(); return listAll; } public String deleteSingleNews(Integer id){ Session session =sf.openSession(); //Session session=sf.getCurrentSession(); Query query =session.createQuery("from News where id=:myid"); query.setParameter("myid", id); List<News> deleteList=query.getResultList(); String returnValue="fail"; if(deleteList.size()==1){ News news=deleteList.get(0); session.getTransaction().begin(); session.delete(news); returnValue="deleteList"; session.getTransaction().commit(); session.close(); } return returnValue; } }
package news.service; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import news.dao.NewsDao; import news.entity.News; public class NewsServiceImpl implements NewsService { //@Resource(name="myNewsDao") @Autowired @Qualifier private NewsDao nd=null; public List<News> showAll(){ List<News> listAll=nd.showAll(); return listAll; } public String deleteSingleNews(Integer id){ String returnValue="fail"; returnValue=nd.deleteSingleNews(id); return returnValue; } }
上面的代码，之所以没用jdk自带的注解是因为？
我稍后给大家公布答案~.~
最后，我来给大家说说类注解吧。类注解是什么呢？
用我自己的话来说就是标签的类自动注册到spring容器。
接下来我们来看代码：
其他的都一样，所以后面的就不做批注了。
这了这一步，我们就来公布答案为什么不用jdk自带注解而用spring注解。
写的不好的地方还请大家多多指教~。~
