使用Hibernate过滤集合元素的两种方法

 （1）通过代码
       

List list=session.createQuery("from Programer").list();
        
        for(Iterator iter=list.iterator();iter.hasNext();)
        ...{
           Programer p=(Programer)iter.next();
           Collection pcs=session.createFilter(p.getComputers(), "where this.id>'3'").list();
           
           for(Iterator iter1=pcs.iterator();iter1.hasNext();)...{
               Computer c=(Computer)iter1.next();
               System.out.println(c.getName());
           }          
}

 

（2）通过HBM文件

    注意，必须设置lazy="true" 否则hibernate会预先加载computer数据，达不到过滤器再过滤的效果

      <set name="computers" cascade="save-update" lazy="true">
            <key>
                <column name="programer_id" length="50" />
            </key>
            <one-to-many class="com.Computer" />
            <filter name="idFilter" condition="id>:idStr"></filter>
        </set>
    </class>
    <filter-def name="idFilter">
       <filter-param name="idStr" type="string"/>
    </filter-def>

 

调用过滤器代码

 

List list=session.createQuery("from Programer").list();
        
        for(Iterator iter=list.iterator();iter.hasNext();)
        ...{
           Programer p=(Programer)iter.next();
           Filter filter=session.enableFilter("idFilter");
           filter.setParameter("idStr", "3");
           for(Iterator iter1=p.getComputers().iterator();iter1.hasNext();)...{
               Computer c=(Computer)iter1.next();
               System.out.println(c.getName());
           }          
        }