Hibernate中过滤器的使用

我们有一个Team实体，一个Student实体，他们之间的关系是1对多，Team中持有一个Student集合，如果我们不想检索出全部的student,而是希望检索符合一定条件的Student集合，可以使用HQL和Filter的方

数据库结构：

 

create table testStu (id varchar(32),name varchar(32),age int,team_id varchar(32));

insert into teststu values("1","tom1",11,"1");
insert into teststu values("2","tom2",12,"2");
insert into teststu values("3","tom3",13,"1");
insert into teststu values("4","tom4",14,"2");
insert into teststu values("5","tom5",15,"1");
insert into teststu values("6","tom6",16,"2");
insert into teststu values("7","tom7",17,"1");
insert into teststu values("8","tom8",18,"2");
insert into teststu values("9","tom9",19,"1");
insert into teststu values("10","tom10",20,"2");


create table testteam (id varchar(32) primary key,name varchar(32));

insert into testteam values("1","team1");
insert into testteam values("2","team2");

 POJO:

 

package Search.filter;

public class TestStu ...{
    private String id; //标识id
    private String name; //学生姓名
    private int age; //岁数
    private TestTeam team;
  

     public int getAge() ...{
        return age;
    }

    public String getName() ...{
        return name;
    }



    public void setId(String id) ...{
        this.id = id;
    }

    public void setAge(int age) ...{
        this.age = age;
    }

    public void setName(String stuName) ...{
        this.name = stuName;
    }



    public String getId() ...{
        return id;
    }

    public TestStu() ...{ //无参的构造函数
    }

    public TestTeam getTeam() ...{
        return team;
    }

    public void setTeam(TestTeam team) ...{
        this.team = team;
    }

}


package Search.filter;

import java.util.Set;

public class TestTeam ...{
   private String id;
   private String name;
   private Set students;
public String getId() ...{
    return id;
}
public void setId(String id) ...{
    this.id = id;
}
public String getName() ...{
    return name;
}
public void setName(String name) ...{
    this.name = name;
}
public Set getStudents() ...{
    return students;
}
public void setStudents(Set students) ...{
    this.students = students;
}
}

 

Hibernate.cfg.xml

 

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration>

<session-factory>
    <property name="connection.username">root</property>
    <property name="connection.url">
        jdbc:mysql://localhost:3306/schoolproject?characterEncoding=gb2312&amp;useUnicode=true
    </property>
    <property name="dialect">
        org.hibernate.dialect.MySQLDialect
    </property>
    <property name="myeclipse.connection.profile">mysql</property>
    <property name="connection.password">1234</property>
    <property name="connection.driver_class">
        com.mysql.jdbc.Driver
    </property>
    <property name="hibernate.dialect">
        org.hibernate.dialect.MySQLDialect
    </property>
    <property name="hibernate.show_sql">true</property>
    <property name="current_session_context_class">thread</property>
    <mapping resource="Search/filter/TestStu.hbm.xml" />
    <mapping resource="Search/filter/TestTeam.hbm.xml" />

</session-factory>

</hibernate-configuration>

 

TestStu.hbm.xml

 

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
<hibernate-mapping package="Search.fetch" >
   
    <class name="Search.filter.TestStu" table="teststu" lazy="true">
       <id name="id" column="id" unsaved-value="null">
         <generator class="uuid.hex"></generator>
       </id>

       <property name="name" column="name"></property>
       <property name="age" column="age"></property>
       <many-to-one name="team" column="team_id">
       </many-to-one>
      </class>
</hibernate-mapping>

 

TestTeam.hbm.xml

 

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
<hibernate-mapping>
<class name="Search.filter.TestTeam" table="testteam" lazy="true">
    <id name="id" column="id" unsaved-value="null">
        <generator class="uuid.hex"></generator>
    </id>
    <property name="name" column="name" type="string"></property>
    <set name="students" inverse="true" lazy="true" fetch="select">
      <key column="team_id"></key>
      <one-to-many class="Search.filter.TestStu"/>
     
      <filter name="stuFilter" condition="age>:age"/>
    </set>
 </class>   
 <!-- 定义配置的filter -->
 <filter-def name="stuFilter">
   <filter-param name="age" type="java.lang.Integer"/>
 </filter-def>
</hibernate-mapping>

 

实现方式有三种

（1）HQL条件检索
（2）使用编码式过滤器createFilter(),注意，第一个参数必须是持久化的集合，第二个参数是过滤条件
（3）使用hbm配置文件中的配置filter这样team.getStudent()返回的直接就是经过过滤的集合

 

package Search.filter;

import java.io.File;
import java.util.Iterator;
import java.util.Set;

import org.hibernate.Filter;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

public class Test ...{


    public static void main(String[] args)...{
        String filePath=System.getProperty("user.dir")+File.separator+"src/Search/filter"+File.separator+"hibernate.cfg.xml";
        File file=new File(filePath);
        SessionFactory sessionFactory=new Configuration().configure(file).buildSessionFactory();
        Session session=sessionFactory.openSession();
        Transaction t=(Transaction)session.beginTransaction();
        
        /**//*
         * 目标：查询年龄在15岁以上的学生
         */
        //方法1：使用HQL条件查询
//        TestTeam team=(TestTeam)session.get(TestTeam.class, "1");
//        Query query=session.createQuery("from TestStu s where s.team=:team and s.age>:age");
//        query.setParameter("team",team,Hibernate.entity(TestTeam.class));
//        //或者使用query.setEntity("team",team);
//        query.setParameter("age", 15);
//        List list=query.list();
//        System.out.println(list.size());
//        for (Iterator iterator = list.iterator(); iterator.hasNext();) {
//            TestStu object = (TestStu) iterator.next();
//            System.out.println(object.getAge());
//        }
        
        //方法1：使用集合过滤
//        TestTeam team=(TestTeam)session.get(TestTeam.class, "1");
//        //createFilter的第一个参数必须为持久化的对象
//        Query query=session.createFilter(team.getStudents(), "where this.age>?");
//        query.setParameter(0,15);
//        List list=query.list();
//        for (Iterator iterator = list.iterator(); iterator.hasNext();) {
//            TestStu object = (TestStu) iterator.next();
//            System.out.println(object.getAge());
//        }
        //方法1：使用hbm配置过滤器
        TestTeam team=(TestTeam)session.get(TestTeam.class, "1");
        Filter f=session.enableFilter("stuFilter");
        f.setParameter("age",new Integer(15));
        Set list=team.getStudents();
        for (Iterator iterator = list.iterator(); iterator.hasNext();) ...{
            TestStu object = (TestStu) iterator.next();
            System.out.println(object.getAge());
        }
        t.commit();

    }

}