博客开发笔记二——Spring3 数据库最小系统

 

在Spring 3中开发数据库应用其实挺简单的，只要在Spring3的最小配置基础上，稍微配置一下就好了，如下所示：

       < bean   id = "oracleDataSource"   class = "org.apache.commons.dbcp.BasicDataSource"

             destroy-method = "close" >

             < property   name = "driverClassName"   value = "oracle.jdbc.driver.OracleDriver"   />

             < property   name = "url"   value = "jdbc:oracle:thin:@localhost:1521:WebLog"   />

             < property   name = "username"   value = "admin"   />

             < property   name = "password"   value = "admin"   />

       </ bean >

上面就不解释了，你懂的。下面主要使用注解的方式，有以下几个特点：

1、类是 AnnotationSessionFactoryBean

2、有一个属性 packagesToScan 指定的是注解扫描的路径

3、Hibernate的属性 hibernate.hbm2ddl.auto 如果是create会自动建表

       < bean   id = "sessionFactory"

             class = "org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean" >

             < property   name = "dataSource"   ref = "oracleDataSource"   />

             < property   name = "packagesToScan" >

                   < list >

                         < value > myproject.module.* </ value >

                   </ list >

             </ property >

             < property   name = "hibernateProperties" >

                   < props >

                         < prop   key = "hibernate.dialect" >

                              org.hibernate.dialect.OracleDialect

                  </ prop >

                         < prop   key = "hibernate.hbm2ddl.auto" >

                              update

                  </ prop >

                         < prop   key = "hibernate.show_sql" >

                              true

                  </ prop >

                         < prop   key = "hibernate.format_sql" > basic </ prop >

                         <!-- 连接释放 -->

                         < prop   key = "hibernate.connection.release_mode" > after_transaction </ prop >

                   </ props >

             </ property >

       </ bean >

配置依然是很简单，接下来 创建实体类，也很简单，不解释了：

@Entity

@Table (name= "article" )

public   class   Article {

       @ Id

       @GeneratedValue

       @Column

       private   long   id ;

      

       @Column

       private   String   title ;

      

       @Column

       @Lob

       @Basic (fetch=FetchType. LAZY )

       private   String   content ;

      

       @ManyToOne

       @JoinColumn (name= "username" )

       private   User   author ;

      

       @Column

       private   Date   createDate ;

      

       @Column

       private   Date   updateDate ;

       public   long   getId() {

             return   id ;

      }

       public   void   setId( long   id) {

             this . id   = id;

      }

       public   String getTitle() {

             return   title ;

      }

       public   void   setTitle(String title) {

             this . title   = title;

      }

       public   String getContent() {

             return   content ;

      }

       public   void   setContent(String content) {

             this . content   = content;

      }

       public   User getAuthor() {

             return   author ;

      }

       public   void   setAuthor(User author) {

             this . author   = author;

      }

       public   Date getCreateDate() {

             return   createDate ;

      }

       public   void   setCreateDate(Date createDate) {

             this . createDate   = createDate;

      }

       public   Date getUpdateDate() {

             return   updateDate ;

      }

       public   void   setUpdateDate(Date updateDate) {

             this . updateDate   = updateDate;

      }

      

}

最后创建DAO类，可以操作数据库了， @Repository 注解就是告诉Spring这个Bean是数据存储的 ：

@Repository

public   class   ContentDao   extends   CommonDao<Article>   {

      

       public   List<Article> list() {

            Session session = openSession();

             return   session.createQuery( "from Article order by updateDate desc" ).list() ;

      }

      

       public   List<Article> list( int   start,   int   count) {

            Session session = openSession();

            Query query = session.createQuery( "from Article order by updateDate desc" );

            query.setFirstResult(start);

            query.setMaxResults(count);

             return   query.list() ;

      }

      

       public   Article get(Long id) {

            Session session = openSession();

            Article article = (Article) session.get(Article. class , id);

            session.close();

             return   article;

      }

      

       public   long   getArticleCount() {

            Query query = openSession().createQuery( "select count(id) from Article" );

             return   (Long) query.uniqueResult();

      }

}

是不是很简单，使用注解真的很简单，总结一下只需三步即可：

1、配置

2、编写实体Bean

3、编写DAO