下面是一个示例 服务的示例,该示例使用 进行持久性而使用 进行消息传递,实现为会话Bean 。
package org.example;
import java.util.List;
import javax.ejb.*;
import javax.persistence.*;
import javax.ws.rs.*;
import javax.ws.rs.core.MediaType;
@Stateless
@LocalBean
@Path("/customers")
public class CustomerService {
@PersistenceContext(unitName="CustomerService",
type=PersistenceContextType.TRANSACTION)
EntityManager entityManager;
@POST
@Consumes(MediaType.APPLICATION_XML)
public void create(Customer customer) {
entityManager.persist(customer);
}
@GET
@Produces(MediaType.APPLICATION_XML)
@Path("{id}")
public Customer read(@PathParam("id") long id) {
return entityManager.find(Customer.class, id);
}
@PUT
@Consumes(MediaType.APPLICATION_XML)
public void update(Customer customer) {
entityManager.merge(customer);
}
@DELETE
@Path("{id}")
public void delete(@PathParam("id") long id) {
Customer customer = read(id);
if(null != customer) {
entityManager.remove(customer);
}
}
@GET
@Produces(MediaType.APPLICATION_XML)
@Path("findCustomersByCity/{city}")
public List<Customer> findCustomersByCity(@PathParam("city") String city) {
Query query = entityManager.createNamedQuery("findCustomersByCity");
query.setParameter("city", city);
return query.getResultList();
}
}
以下是其中一个实体的示例。它包含JPA和JAXB批注。
package org.example;
import java.io.Serializable;
import javax.persistence.*;
import javax.xml.bind.annotation.XmlRootElement;
import java.util.Set;
@Entity
@NamedQuery(name = "findCustomersByCity",
query = "SELECT c " +
"FROM Customer c " +
"WHERE c.address.city = :city")
@XmlRootElement
public class Customer implements Serializable {
private static final long serialVersionUID = 1L;
@Id
private long id;
@Column(name="FIRST_NAME")
private String firstName;
@Column(name="LAST_NAME")
private String lastName;
@OneToOne(mappedBy="customer", cascade={CascadeType.ALL})
private Address address;
@OneToMany(mappedBy="customer", cascade={CascadeType.ALL})
private Set<PhoneNumber> phoneNumbers;
}
需要什么jar
您可以将JAX-RS / EJB / JPA / JAXB应用程序部署到任何符合Java EE 6的应用程序服务器,而无需设置任何其他服务器。对客户端进行编程,您可以从Jersey(http://jersey.java.net/)获得JAX- RS API ,并从EclipseLink(http://www.eclipse.org/eclipselink/)获得JPA和JAXB API 。
以及数据库连接的写入位置
您需要在应用程序服务器上配置连接池。以下是在GlassFish上执行此操作的步骤。步骤将因所使用的应用程序服务器而异。
然后,我们参考上面在persistence.xml
文件中为JPA实体创建的数据库连接,如下所示:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0"
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_1_0.xsd">
<persistence-unit name="CustomerService" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<jta-data-source>CustomerService</jta-data-source>
<class>org.example.Customer</class>
<class>org.example.Address</class>
<class>org.example.PhoneNumber</class>
<properties>
<property name="eclipselink.target-database" value="Oracle" />
<property name="eclipselink.logging.level" value="FINEST" />
<property name="eclipselink.logging.level.ejb_or_Metadata" value="WARNING" />
<property name="eclipselink.logging.timestamp" value="false"/>
<property name="eclipselink.logging.thread" value="false"/>
<property name="eclipselink.logging.session" value="false"/>
<property name="eclipselink.logging.exceptions" value="false"/>
<property name="eclipselink.target-server" value="SunAS9"/>
</properties>
</persistence-unit>
</persistence>