?以下是兩個hibernate映射文件：Activity:<?xml?version="1.0"?encoding="gb2312"?> <!DOCTYPE?hibernate-mapping?PUBLIC??? ????"-//Hibernate/Hibernate?Mapping?DTD?3.0//EN"?? ????"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">? <hibernate-mapping?package="com.ywt.domain">?? ????<class?name="Activity"?table="activity"?lazy="true">?? ????????<!--?id元素定義持久化類的標(biāo)識屬性?-->?? ????????<id?name="id"> ????????????<!--?指定主鍵生成策略?-->?? ????????????<generator?class="native"?/>?? ????????</id>?? ????????<!--?property元素定義常規(guī)屬性?-->?? ????????<property?name="name"?not-null="true"/>?? ????????<property?name="time"?not-null="true"/>?? ????????<property?name="imageurl"?not-null="true"/>?? ????????<property?name="hostone"?not-null="true"/>?? ????????<property?name="hosttwo"?not-null="true"/>?? ????????<property?name="introduce"?not-null="true"/>?? ????????<property?name="problem"?/>?? ????????<property?name="award"?/>?? ????????<property?name="schedule"?/>?? ????????<property?name="number"?/>?? ????????<property?name="status"?not-null="true"/>?? ????????<set?name="studentSet"?table="activity_student"?inverse="true"> ???????? <key> ???????? <column?name="A_ID"></column> ???????? </key> ???????? <many-to-many?class="Student"?column="S_ID"?></many-to-many> ????????</set>?? ????</class>?? </hibernate-mapping>Student:<?xml?version="1.0"?encoding="gb2312"?> <!DOCTYPE?hibernate-mapping?PUBLIC??? ????"-//Hibernate/Hibernate?Mapping?DTD?3.0//EN"?? ????"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">? <hibernate-mapping?package="com.ywt.domain">?? ????<!--?每個class元素對應(yīng)一個持久化對象?lazy="true"?代表加載延遲?對象A對對象B引用才會用到-->?? ????<class?name="Student"?table="student"?lazy="true">?? ????????<!--?id元素定義持久化類的標(biāo)識屬性?-->?? ????????<id?name="id"> ????????????<!--?指定主鍵生成策略?-->?? ????????????<generator?class="native"?/>?? ????????</id>?? ????????<!--?property元素定義常規(guī)屬性?-->?? ????????<property?name="username"?not-null="true"/>?? ????????<property?name="password"?not-null="true"/>?? ????????<property?name="name"?not-null="true"/>?? ????????<property?name="sex"?not-null="true"/>?? ????????<property?name="major"?not-null="true"/>?? ????????<property?name="academy"?not-null="true"/>?? ????????<property?name="tel"?/>?? ????????<property?name="coin"/>?? ????????<property?name="activities"?/>?? ????????<property?name="honor"?/>? ????????<set?name="activitySet"?table="activity_student"> ???????? <key> ???????? <column?name="S_ID"></column> ???????? </key> ???????? <many-to-many?class="Activity"?column="A_ID"></many-to-many> ????????</set>?? ????</class>?? </hibernate-mapping>所出現(xiàn)的問題是：只要Activity映射文件中一加set集合就報如下錯誤（Student映射文件中加set不報錯，已確認各屬性書寫沒錯誤）：嚴(yán)重: Servlet.service() for servlet [mvc] in context with path [/dxshdw] threw exception [Handler processing failed; nested exception is java.lang.NoClassDefFoundError: Could not initialize class com.ywt.util.HibernateUtil] with root causejava.lang.NoClassDefFoundError: Could not initialize class com.ywt.util.HibernateUtil其中HibernateUtil是獲取session工廠的類