hibernate双向多对一(一对多)及自身一对多关联

/**
*
* 双向的一对多（多对一）
* 少的一端,需要对多的一端进行集合的引用
*/
public class Account {

private int id;
private String accName;

//对多端对象集合的引用
private Set<Orders> setOrders;

public Account(){

}

/**
* @return the id
*/
public int getId() {
return id;
}

/**
* @param id the id to set
*/
public void setId(int id) {
this.id = id;
}

/**
* @return the accName
*/
public String getAccName() {
return accName;
}

/**
* @param accName the accName to set
*/
public void setAccName(String accName) {
this.accName = accName;
}

/**
* @return the setOrders
*/
public Set<Orders> getSetOrders() {
return setOrders;
}

/**
* @param setOrders the setOrders to set
*/
public void setSetOrders(Set<Orders> setOrders) {
this.setOrders = setOrders;
}

}

/**
*
* 双向的一对多（多对一）
* 多的一端需要对少的一端进行对象的引用
*/
public class Orders {

private int id;
private String orderNum;
private Date orderTime;
private Account account;

public Orders(){

}

/**
* @return the id
*/
public int getId() {
return id;
}

/**
* @param id the id to set
*/
public void setId(int id) {
this.id = id;
}

/**
* @return the orderNum
*/
public String getOrderNum() {
return orderNum;
}

/**
* @param orderNum the orderNum to set
*/
public void setOrderNum(String orderNum) {
this.orderNum = orderNum;
}

/**
* @return the orderTime
*/
public Date getOrderTime() {
return orderTime;
}

/**
* @param orderTime the orderTime to set
*/
public void setOrderTime(Date orderTime) {
this.orderTime = orderTime;
}

public Account getAccount() {
return account;
}

public void setAccount(Account account) {
this.account = account;
}

}

<?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>
<!-- name属性指定类名（全限定名） table指明表名，不指明table数据默认的表名和实体名一致 -->
<class name="com.entity.Account" table="acc_tab">
<!-- type指明当前字段的类型    name对应实体中的属性名 -->
<id type="integer" name="id">
<!-- 提供ID自增的策略  native会根据数据库自行判断 -->
<generator class="native"/>
</id>
<property name="accName" type="string"></property>
<set name="setOrders" cascade="all" inverse="true">
<key column="acc_id"></key>
<one-to-many class="com.entity.Orders"/>
</set>

</class>
</hibernate-mapping>

<?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>
<!-- name属性指定类名（全限定名） table指明表名，不指明table数据默认的表名和实体名一致 -->
<class name="com.entity.Orders" table="order_tab">
<!-- type指明当前字段的类型    name对应实体中的属性名 -->
<id type="integer" name="id">
<!-- 提供ID自增的策略  native会根据数据库自行判断 -->
<generator class="native"/>
</id>
<property name="orderNum" type="string"></property>
<property name="orderTime" type="timestamp"></property>

<many-to-one name="account" column="acc_id"></many-to-one>

</class>
</hibernate-mapping>

@Test
public void add(){
Transaction tx=null;
Session session=null;
try{
session=HibernateUtils.getSession();
tx=session.beginTransaction();
Account account=new Account();
account.setAccName("lm");
Orders order1=new Orders();
order1.setOrderNum("100");
order1.setOrderTime(new Date());
//session.save(order1);

Orders order2=new Orders();
order2.setOrderNum("10061");
order2.setOrderTime(new Date());
//session.save(order2);

order1.setAccount(account);
order2.setAccount(account);
Set<Orders> setOrders=new HashSet<Orders>();
setOrders.add(order1);
setOrders.add(order2);
account.setSetOrders(setOrders);

session.save(account);
tx.commit();
}catch(HibernateException he){
if(tx!=null){
tx.rollback();
}
he.printStackTrace();
}finally{
HibernateUtils.closeSession(session);
}
}

/**
*
* 双向一对多或多对一 自身关联
*
*/
public class Category {

private int id;
private String name;

//如果把Category看成是多的一端
private Category parent;

//如果把Category看成是少的一端,则需要对多的一端进行对象集合的引用
private Set<Category> clist;

public Category(){

}

/**
* @return the id
*/
public int getId() {
return id;
}

/**
* @param id the id to set
*/
public void setId(int id) {
this.id = id;
}

/**
* @return the name
*/
public String getName() {
return name;
}

/**
* @param name the name to set
*/
public void setName(String name) {
this.name = name;
}

/**
* @return the parent
*/
public Category getParent() {
return parent;
}

/**
* @param parent the parent to set
*/
public void setParent(Category parent) {
this.parent = parent;
}

/**
* @return the clist
*/
public Set<Category> getClist() {
return clist;
}

/**
* @param clist the clist to set
*/
public void setClist(Set<Category> clist) {
this.clist = clist;
}

}

<?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>
<!-- name属性指定类名（全限定名） table指明表名，不指明table数据默认的表名和实体名一致 -->
<class name="com.entity.Category" table="cate_tab">
<!-- type指明当前字段的类型    name对应实体中的属性名 -->
<id type="integer" name="id">
<!-- 提供ID自增的策略  native会根据数据库自行判断 -->
<generator class="native"/>
</id>
<property name="name" type="string"></property>
<set name="clist" inverse="true">
<key column="parent_id"></key>
<!-- 配置一对多的关联映射 -->
<one-to-many class="com.entity.Category"/>
</set>
<many-to-one name="parent" column="parent_id"></many-to-one>

</class>
</hibernate-mapping>

@Test
public void add(){
Transaction tx=null;
Session session=null;
try{
session=HibernateUtils.getSession();
tx=session.beginTransaction();
//添加一级分类
Category c1=new Category();
c1.setName("computer");

session.save(c1);

//添加二级分类
Category c2=new Category();
c2.setName("java");
c2.setParent(c1);
session.save(c2);
//添加二级分类
Category c3=new Category();
c3.setName(".net");
c3.setParent(c1);
session.save(c3);
tx.commit();
}catch(HibernateException he){
if(tx!=null){
tx.rollback();
}
he.printStackTrace();
}finally{
HibernateUtils.closeSession(session);
}
}