精通Hibernate类与类关联关系：[三]映射一对多双向自身关联关系

三、映射一对多双向自身关联关

Category.java:

package mypack;
import java.util.HashSet;
import java.util.Set;
publicclass Category  implements java.io.Serializable {
     privatelong id;
     private String name;
     private Set childCategories = new HashSet(0);
     private Category parentCategory;
    public Category() {
                }
    public Category(String name, Set childCategories, Category parentCategory) {
       this.name = name;
       this.childCategories = childCategories;
       this.parentCategory = parentCategory;
    }

    publiclong getId() {
        returnthis.id;
    }

    publicvoid setId(long id) {
        this.id = id;
    }
    public String getName() {
        returnthis.name;
    }

    publicvoid setName(String name) {
        this.name = name;
    }
    public Set getChildCategories() {
        returnthis.childCategories;
    }

    publicvoid setChildCategories(Set childCategories) {
        this.childCategories = childCategories;
    }
    public Category getParentCategory() {
        returnthis.parentCategory;
    }

    publicvoid setParentCategory(Category parentCategory) {
        this.parentCategory = parentCategory;
    }
}

      配置文件Category.hbm.xml:

<?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.Category" table="CATEGORIES" >
    <id name="id" type="long" column="ID">
      <generator class="increment"/>
    </id>
    <property name="name" type="string" >
        <column name="NAME" length="15" />
    </property>
    <set
        name="childCategories"
        cascade="save-update"
        inverse="true"
        >
        <key column="CATEGORY_ID" />
        <one-to-many class="mypack.Category" />
     </set>
   <many-to-one
        name="parentCategory"
        column="CATEGORY_ID"
        class="mypack.Category"
       />
  </class>
</hibernate-mapping>