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();
        }
    }

}