Hibernate逍遥游记-第12章 映射值类型集合-005对集合排序(<order-by>\<sort>)

1.

2.

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

   <class name="mypack.Monkey" table="MONKEYS" >
     <id name="id" type="long" column="ID">
       <generator class="increment"/>
     </id>

     <property name="name" type="string" >
         <column name="NAME" length="15" />
     </property>

    <property name="age" type="int" >
         <column name="AGE" />
    </property>

    <set   name="images"   table="IMAGES"    lazy="true" sort="natural" >

    <!--
    <set   name="images"   table="IMAGES"    lazy="true" sort="mypack.ReverseStringComparator">
    -->

      <key column="MONKEY_ID" />
         <element column="FILENAME" type="string"  not-null="true"/>
    </set>   

   </class>

 </hibernate-mapping>

3.

 package mypack;

 import java.io.Serializable;
 import java.util.Set;
 import java.util.TreeSet;

 public class Monkey implements Serializable {
     private Long id;
     private String name;
     private int age;
     private Set images=new TreeSet();

     /** full constructor */
     public Monkey(String name, int age,Set images) {
         this.name = name;
         this.age=age;
         this.images = images;
     }

     /** default constructor */
     public Monkey() {
     }

     /** minimal constructor */
     public Monkey(Set images) {
         this.images = images;
     }

     public Long getId() {
         return this.id;
     }

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

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

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

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

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

     public Set getImages() {
         return this.images;
     }

     public void setImages(Set images) {
         this.images = images;
     }

 }

4.

 package mypack;

 import java.util.*;
 public class ReverseStringComparator implements Comparator{

   public int compare(Object o1,Object o2){
     String s1=(String)o1;
     String s2=(String)o2;

     if(s1.compareTo(s2)>0) return -1;
     if(s1.compareTo(s2)<0) return 1;

     return 0;
   }
 }

5.