java hibernate of the associated one-way based on the foreign key mapping

This explanation based on the associated one-way foreign key mapping

1. examine the following information is a one to one relationship between human identity card. Table design

Note: Based on the table structure and many-to-one association table structure of the foreign key is consistent, however, the foreign key is unique.

2. The structure of the class

Person.java

public class Person implements Serializable{
    private int id;
    private String name;
    private IdCard idCard;
    public Person() {
    }
    public Person(String name) {
        super();
        this.name = name;
    }

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public IdCard getIdCard() {
        return idCard;
    }
    public void setIdCard(IdCard idCard) {
        this.idCard = idCard;
    }
}

IdCard.java

public class IdCard implements Serializable{
    private String id;
    private String address;
    public IdCard() {
        // TODO Auto-generated constructor stub
    }
    
    public IdCard(String id, String address) {
        super();
        this.id = id;
        this.address = address;
    }

    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    
}

3. Mapping file information:

IdCard.hbm.xml

<hibernate-mapping package="cn.sxt.pojo">
    <class name="IdCard" table="t_idCard">
        <id name="id">
            <generator class="assigned"></generator>
        </id>
        <property name="address"/>
    </class>
</hibernate-mapping>

Person.hbm.xml

<-Hibernate Mapping Package = "cn.sxt.pojo"> 
    < class name = " the Person " Table = "t_person"> 
        <name ID = "ID"> 
            <Generator class = "Native"> </ Generator> 
        </ ID > 
        <Property name = "name" /> 
        <-! on-one and many-to-foreign key table structure is the same, so the mapping file is the same, to ensure that the foreign key is unique -> 
        < MANY One--to name = "idCard" column = "idCardId" UNIQUE = "to true" > </ MANY-to-One> 
    </ class > 
</ Hibernate-Mapping>

4. Test

public  class HibernateTest {
     / ** 
     * means a method for generating database tables 
     * * / 
    @Test 
    public  void testCreateDB () { 
        the Configuration CFG = new new the Configuration () Configure ();. 
        the SchemaExport SE = new new the SchemaExport (CFG);
         // first sql script print parameters whether
         // if the second parameter to the database exported script execution 
        se.create ( to true , to true ); 
    } 
    / ** 
     * initialization table data
      * / 
    @Test 
    public  void testInit () {
        Session session = null;
        Transaction tx = null;
        try {
            session = HibernateUtil.getSession();
            tx = session.beginTransaction();
            IdCard card1 = new IdCard("110086", "湖北武当");
            IdCard card2 = new IdCard("110087", "光明顶");
            Person p1 = new Person("张三疯");
            p1.setIdCard(card1);
            Person p2 = new Person("殷素素");
            p2.setIdCard(card2);
            session.save(card1);
            session.save(card2);
            session.save(p1);
            session.save(p2);
            tx.commit();
            
        } catch (Exception e) {
            if(tx!=null)
                tx.rollback();
        }finally {
            HibernateUtil.close();
        }
    }
    /**
     */
    @Test
    public void testGetData(){
        Session session = HibernateUtil.getSession();
        Person p1 = (Person)session.get(Person.class, 1);
        System.out.println(p1.getName()+"----"+p1.getIdCard().getId()+"----"+p1.getIdCard().getAddress());
        HibernateUtil.close();
    }
}