5.9. JPA

在以下示例中，您可以使用 JBoss EAP in-memory ExampleDS 数据源，该数据源在 JBoss EAP standalone.xml 配置文件中配置。

<persistence version="2.0"
    xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">

    <persistence-unit name="camel">
        <jta-data-source>java:jboss/datasources/ExampleDS</jta-data-source>
        <class>org.wildfly.camel.test.jpa.model.Customer</class>
        <properties>
            <property name="hibernate.hbm2ddl.auto" value="create-drop"/>
            <property name="hibernate.show_sql" value="true"/>
        </properties>
    </persistence-unit>

</persistence>

@Entity
@Table(name = "customer")
public class Customer implements Serializable {
    @Id
    @GeneratedValue
    private Long id;
    private String firstName;
    private String lastName;

    public Customer() {
    }

    public Customer(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    public Long getId() {
        return id;
    }

    public void setId(final Long id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
}

配置 JPA 后，您可以使用 CDI 将 EntityManager 和 UserTransaction 实例注入 RouteBuilder 类或测试案例中：

@PersistenceContext
EntityManager em;

@Inject
UserTransaction userTransaction;

现在，配置 Camel 路由和 JPA 端点：

WildFlyCamelContext camelctx = contextFactory.createCamelContext(getClass().getClassLoader());

EntityManagerFactory entityManagerFactory = em.getEntityManagerFactory();

// Configure a transaction manager
JtaTransactionManager transactionManager = new JtaTransactionManager();
transactionManager.setUserTransaction(userTransaction);
transactionManager.afterPropertiesSet();

// Configure the JPA endpoint to use the correct EntityManagerFactory and JtaTransactionManager
final JpaEndpoint jpaEndpoint = new JpaEndpoint();
jpaEndpoint.setCamelContext(camelctx);
jpaEndpoint.setEntityType(Customer.class);
jpaEndpoint.setEntityManagerFactory(entityManagerFactory);
jpaEndpoint.setTransactionManager(transactionManager);

camelctx.addRoutes(new RouteBuilder() {
@Override
public void configure() throws Exception {
    from("direct:start")
    .to(jpaEndpoint);
}
});

camelctx.start();

最后，您可以将 'Customer' 实体发送到 'direct:start' 端点，然后查询 ExampleDS 数据源来验证已保存记录。

Customer customer = new Customer("John", "Doe");
ProducerTemplate producer = camelctx.createProducerTemplate();
producer.sendBody("direct:start", customer);

// Query the in memory database customer table to verify that a record was saved
CriteriaBuilder criteriaBuilder = em.getCriteriaBuilder();
CriteriaQuery<Long> query = criteriaBuilder.createQuery(Long.class);
query.select(criteriaBuilder.count(query.from(Customer.class)));

long recordCount = em.createQuery(query).getSingleResult();

Assert.assertEquals(1L, recordCount);