hibernate 多对多数据表配置

一 多对多配置（以角色和用户为例）

1 创建两个实体类（Role 和 User）,代码如下：

public class User {


private Integer user_id;
private String user_name;
private String user_password;

//一个用户对应多个角色
private Set<Role> SetRole = new HashSet<Role>();



public Set<Role> getSetRole() {
return SetRole;
}

public void setSetRole(Set<Role> setRole) {
SetRole = setRole;
}

public Integer getUser_id() {
return user_id;
}
public void setUser_id(Integer user_id) {
this.user_id = user_id;
}
public String getUser_name() {
return user_name;
}
public void setUser_name(String user_name) {
this.user_name = user_name;
}
public String getUser_password() {
return user_password;
}
public void setUser_password(String user_password) {
this.user_password = user_password;
}

public class Role {


private Integer role_id;
private String role_name;
private String role_memo;


//一个角色对应多个用户
private Set<User> SetCustum = new HashSet<User>() ;



public Set<User> getSetCustum() {
return SetCustum;
}

public void setSetCustum(Set<User> setCustum) {
SetCustum = setCustum;
}

public Integer getRole_id() {
return role_id;
}
public void setRole_id(Integer role_id) {
this.role_id = role_id;
}
public String getRole_name() {
return role_name;
}
public void setRole_name(String role_name) {
this.role_name = role_name;
}
public String getRole_memo() {
return role_memo;
}
public void setRole_memo(String role_memo) {
this.role_memo = role_memo;
}

2 连个实体类基本映射配置：代码如下：

Role.hbm.xml 文件配置如下：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    
 <hibernate-mapping>
 
   <class name="com.grl.manytomany.Role" table="t_role">
   <id name="role_id" column="role_id">
     <generator class="native"></generator>
   </id>
   <property name="role_name" column="role_name"></property>
   <property name="role_memo" column="role_memo"></property>
   
   <set name="SetCustum" table="uer2_role">
      <key column="roleid"></key>
      <many-to-many class="com.grl.manytomany.User" column = "userid"></many-to-many>
   </set>
   </class>

User.hbm.xml 文件配置如下：

<?xml version="1.0" encoding="UTF-8"?>


<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="com.grl.manytomany.User"  table="t_user2">
      <id name="user_id" column="user_id">
        <generator class="native"></generator>
      </id>
      <property name="user_name" column="user_name"></property>
      <property name="user_password" column="user_password"></property>
      
      <set name="SetRole" table="uer2_role" cascade="save-update,delete">
      
        <key column="userid"></key>
       
        <many-to-many class="com.grl.manytomany.Role" column = "roleid"></many-to-many>
      </set>
    </class>
</hibernate-mapping>
   
 </hibernate-mapping>

3 核心配置文件的映射，代码如下：

<mapping resource="com/grl/manytomany/Role.hbm.xml" />
      <mapping resource="com/grl/manytomany/User.hbm.xml" />

4 测试，执行单元测试代码，就会在数据库中生成三张数据表

public class OneToManyTest {


@Test
public void test()
{
SessionFactory sessionFactory = HibernateUtils.getSessionFactory();
}
}