JavaPersistenceWithHibernate第二版笔记-第六章-Mapping inheritance-009Polymorphic collections(@OneToMany(mappedBy = "user")、@ManyToOne、)

一、代码

1.

 package org.jpwh.model.inheritance.associations.onetomany;

 import org.jpwh.model.Constants;

 import javax.persistence.*;
 import javax.validation.constraints.NotNull;

 // Can not be @MappedSuperclass when it's a target class in associations!
 @Entity
 @Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
 public abstract class BillingDetails {

     @Id
     @GeneratedValue(generator = Constants.ID_GENERATOR)
     protected Long id;

     @ManyToOne(fetch = FetchType.LAZY)
     protected User user;

     @NotNull
     protected String owner;

     protected BillingDetails() {
     }

     protected BillingDetails(String owner) {
         this.owner = owner;
     }

     public Long getId() {
         return id;
     }

     public String getOwner() {
         return owner;
     }

     public void setOwner(String owner) {
         this.owner = owner;
     }

     public User getUser() {
         return user;
     }

     public void setUser(User user) {
         this.user = user;
     }

     public void pay(int amount) {
         // NOOP
     }

     // ...
 }

2.

 package org.jpwh.model.inheritance.associations.onetomany;

 import javax.persistence.Entity;
 import javax.validation.constraints.NotNull;

 @Entity
 public class BankAccount extends BillingDetails {

     @NotNull
     protected String account;

     @NotNull
     protected String bankname;

     @NotNull
     protected String swift;

     public BankAccount() {
         super();
     }

     public BankAccount(String owner, String account, String bankname, String swift) {
         super(owner);
         this.account = account;
         this.bankname = bankname;
         this.swift = swift;
     }

     public String getAccount() {
         return account;
     }

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

     public String getBankname() {
         return bankname;
     }

     public void setBankname(String bankname) {
         this.bankname = bankname;
     }

     public String getSwift() {
         return swift;
     }

     public void setSwift(String swift) {
         this.swift = swift;
     }
 }

3.

 package org.jpwh.model.inheritance.associations.onetomany;

 import javax.persistence.Entity;
 import javax.validation.constraints.NotNull;

 @Entity
 public class CreditCard extends BillingDetails {

     @NotNull
     protected String cardNumber;

     @NotNull
     protected String expMonth;

     @NotNull
     protected String expYear;

     public CreditCard() {
         super();
     }

     public CreditCard(String owner, String cardNumber, String expMonth, String expYear) {
         super(owner);
         this.cardNumber = cardNumber;
         this.expMonth = expMonth;
         this.expYear = expYear;
     }

     public String getCardNumber() {
         return cardNumber;
     }

     public void setCardNumber(String cardNumber) {
         this.cardNumber = cardNumber;
     }

     public String getExpMonth() {
         return expMonth;
     }

     public void setExpMonth(String expMonth) {
         this.expMonth = expMonth;
     }

     public String getExpYear() {
         return expYear;
     }

     public void setExpYear(String expYear) {
         this.expYear = expYear;
     }

 }

4.

 package org.jpwh.model.inheritance.associations.onetomany;

 import org.jpwh.model.Constants;

 import javax.persistence.*;
 import javax.validation.constraints.NotNull;
 import java.util.HashSet;
 import java.util.Set;

 @Entity
 @Table(name = "USERS")
 public class User {

     @Id
     @GeneratedValue(generator = Constants.ID_GENERATOR)
     protected Long id;

     @NotNull
     protected String username;

     @OneToMany(mappedBy = "user")
     protected Set<BillingDetails> billingDetails = new HashSet<>();

     public User() {
     }

     public User(String username) {
         this.username = username;
     }

     public Long getId() {
         return id;
     }

     public String getUsername() {
         return username;
     }

     public void setUsername(String username) {
         this.username = username;
     }

     public Set<BillingDetails> getBillingDetails() {
         return billingDetails;
     }

     public void setBillingDetails(Set<BillingDetails> billingDetails) {
         this.billingDetails = billingDetails;
     }

     // ...
 }

5.测试

 package org.jpwh.test.inheritance;

 import org.jpwh.env.JPATest;
 import org.jpwh.model.inheritance.associations.onetomany.BankAccount;
 import org.jpwh.model.inheritance.associations.onetomany.BillingDetails;
 import org.jpwh.model.inheritance.associations.onetomany.CreditCard;
 import org.jpwh.model.inheritance.associations.onetomany.User;
 import org.testng.annotations.BeforeClass;
 import org.testng.annotations.Test;

 import javax.persistence.EntityManager;
 import javax.transaction.UserTransaction;

 import static org.testng.Assert.assertEquals;

 public class PolymorphicOneToMany extends JPATest {

     @Override
     public void configurePersistenceUnit() throws Exception {
         configurePersistenceUnit("PolymorphicOneToManyPU");
     }

     @Test
     public void storeAndLoadItemBids() throws Exception {
         UserTransaction tx = TM.getUserTransaction();
         try {
             tx.begin();
             EntityManager em = JPA.createEntityManager();

             BankAccount ba = new BankAccount(
                 "Jane Roe", "445566", "One Percent Bank Inc.", "999"
             );
             CreditCard cc = new CreditCard(
                 "John Doe", "1234123412341234", "06", "2015"
             );
             User johndoe = new User("johndoe");

             johndoe.getBillingDetails().add(ba);
             ba.setUser(johndoe);

             johndoe.getBillingDetails().add(cc);
             cc.setUser(johndoe);

             em.persist(ba);
             em.persist(cc);
             em.persist(johndoe);

             tx.commit();
             em.close();

             Long USER_ID = johndoe.getId();

             tx.begin();
             em = JPA.createEntityManager();
             {
                 User user = em.find(User.class, USER_ID);

                 for (BillingDetails billingDetails : user.getBillingDetails()) {
                     billingDetails.pay(123);
                 }
                 assertEquals(user.getBillingDetails().size(), 2);
             }

             tx.commit();
             em.close();

         } finally {
             TM.rollback();
         }
     }

 }