Hibernate MTM Federated Primary Key

//apply to Table no other columns, only primary key//course.java entity class PackageCom.tao.pojo;ImportJava.util.HashSet;ImportJava.util.Set; Public classCourse {Private intID; PrivateString name; PrivateSet<student> stu=NewHashset<student>();  PublicCourse () {Super(); }     PublicCourse (intID, String name) {        Super();  This. ID =ID;  This. Name =name; }     Public intgetId () {returnID; }     Public voidSetId (intID) { This. ID =ID; }     PublicString GetName () {returnname; }     Public voidsetName (String name) { This. Name =name; }     PublicSet<student>Getstu () {returnStu; }     Public voidSetstu (set<student>Stu) {         This. Stu =Stu; } @Override PublicString toString () {return"Course [id=" + ID + ", name=" + name + "]"; }}//student.java entity class PackageCom.tao.pojo;ImportJava.util.HashSet;ImportJava.util.Set; Public classStudent {Private intID; PrivateString name; PrivateString Gender; PrivateSet<course> cou=NewHashset<course>();  PublicStudent () {Super(); }     PublicStudent (intID, string name, String gender) {        Super();  This. ID =ID;  This. Name =name;  This. Gender =gender; }     Public intgetId () {returnID; }     Public voidSetId (intID) { This. ID =ID; }     PublicString GetName () {returnname; }     Public voidsetName (String name) { This. Name =name; }     PublicString Getgender () {returngender; }     Public voidSetgender (String gender) { This. Gender =gender; }     PublicSet<course>Getcou () {returncou; }     Public voidSetcou (set<course>cou) {         This. Cou =cou; } @Override PublicString toString () {return"Student [id=" + ID + ", name=" + name + ", gender=" + Gender + "]"; }}//profile//course.hbm.xml file name<?xml version= "1.0"? ><! DOCTYPE hibernate-Mapping Public"-//hibernate/hibernate Mapping DTD 3.0//en" "Http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd" >< Hibernate-mapping> <className= "Com.tao.pojo.Course" table= "Course" > <id name= "id" > <!--auto-grow--<genera Torclass= "Native" ></generator> </id> <property name= "name"/> <!--Name: attribute name in Entity (Claz Z name) Clazz: attribute type (clazz type is clazz)-<!--column: Foreign key Column name--<!--Stu is the name of the set set in the entity class, SC is the table name, CID is course Foreign keys in SC table,--<set name= "Stu" table= "SC" > <key column= "cid" ></key> <! The object type student class SID that is stored in the--set collection is the student foreign key in the SC table--and <many-to-manyclass= "Com.tao.pojo.Student" column= "Sid" ></many-to-many> </set> </class>//Student.hbm.xml<?xml version= "1.0"? ><! DOCTYPE hibernate-Mapping Public"-//hibernate/hibernate Mapping DTD 3.0//en" "Http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd" >< Hibernate-mapping> <className= "Com.tao.pojo.Student" table= "Student" > <id name= "id" > <!--auto-grow--<gene Ratorclass= "Native" ></generator> </id> <!--normal column--<property name= "name"/> & Lt;property name= "Gender"/> <!--the configuration SID of the set set is student column name in the SC table---<set name= "cou" table= "SC"        ; <!--Student own key--<key column= "Sid" ></key> <!--Set Database Type CID is course in SC table Foreign keys--<!--course--<many-to-manyclass= "Com.tao.pojo.Course" column= "CID" ></many-to-many> </set> </class>//Map file Hibernate.cfg.xml
<?xml version= ' 1.0 ' encoding= ' utf-8 '? ><! DOCTYPE hibernate-Configuration Public"-//hibernate/hibernate Configuration DTD 3.0//en" "Http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd" & Gt;//localhost:3306/test0105_mtm</property><property name= "Connection.username" >root</property> <property name= "Connection.password" >root& lt;/property> <property name= "Show_sql" >true</property> <property name= "Format_sql" >true</property> <!--automatically create or update a table (without creating it, update it)-<property name= "Hbm2ddl.auto" >update</propert y> <!--database dialect (set the database dialect if the foreign key is not generated)-<!--Org.hibernate.dialect.MySQL5InnoDBDialect is Mys                The class name of the QL database dialect in the Java file MySQL5 Mysql5innodbdialect-<!--If the execution is finished without an error, the foreign key or not, the table was deleted, and then executed again- <property name= "Hibernate.dialect" >org.hibernate.dialect.MySQL5InnoDBDialect</property> <!--configuration map Pieces--<mapping resource= "Com/tao/pojo/course.hbm.xml"/> <mapping resource= "com/tao/pojo/student . Hbm.xml "/> </session-factory>//Test class//Testjunit.java Packagecom.tao.test;Importorg.hibernate.Session;Importorg.hibernate.SessionFactory;Importorg.hibernate.cfg.Configuration;ImportOrg.junit.After;ImportOrg.junit.Before;Importorg.junit.Test;ImportCom.tao.pojo.Course;Importcom.tao.pojo.Student; Public classTestjunit {sessionfactory factory;    Session session; @Before Public voidtest001 () {Configuration Configure=NewConfiguration (). Configure (); Factory=configure.buildsessionfactory (); Session=factory.opensession ();    Session.begintransaction (); } @After Public voidtest002 () {session.gettransaction (). commit ();        Session.close ();    Factory.close (); } @Test Public voidteststudent () {}} The test class does not have to write content, here with the teststudent() test

Hibernate MTM Federated Primary Key