持久扩展类的适当方法是什么？

考虑图:

我一直在JPA工作了很短的时间,到目前为止,我从来没有需要坚持扩大班......你可以通过的例子,看SNMPNode,IPNode等是从所有的扩展类Node,它也从延长GeoLocation.

我知道我可以使用and 来修改主类,@MappedSuperclass并且将继承它们的属性以便持久化......但是在这种情况下,我将得到几乎相同的表,据我所知,我可以将所有信息分组到节点并使用单个表.IPNodeSNMPNode

这是JPA工作或我的概念上的扩展类的持久性是错误的吗？

与恢复的代码相同:

public class Node extends GeoLocation {
    private String name;
    private Group group;
    private Location location;
    private Type type;
    private Company company;
}

public class IPNode extends Node {
    private Long id;
    private String ipAddress;
}

public class SNMPNode extends Node {
    private Long id;
    private SNMPServer server;
}

[[在此点之后回复]]

为了贡献,这里有一个我最终做的样本:

索引节点:

public interface INode {
    public Long getId();
    public void setId(Long id);

    public String getName();
    public void setName(String name);

    public String getIpAddress();
    public void setIpAddress(String ipAddress);

    public String getCommunity();
    public void setCommunity(String community);
}

节点:

@Entity
@DiscriminatorValue("N")
@DiscriminatorColumn(name="NODE_TYPE",discriminatorType=DiscriminatorType.STRING, length=20)
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
public abstract class Node extends GeoLocation implements INode {
    @Id
    @GeneratedValue
    private Long id;
    private String name;

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

    public String getName() {return name;}
    public void setName(String name) {this.name = name;}

    (... Overrides from INode ...)
}

IPNode:

@Entity
@DiscriminatorValue("I")
public class IPNode extends Node {
    private String ipAddress;

    public String getIpAddress() { return this.ipAddress;}
    public void setIpAddress(String ipAddress) { this.ipAddress = ipAddress; }

    (... Overrides from INode ...)
}

SNMPNode:

@Entity
@DiscriminatorValue("S")
public class SNMPNode extends Node {
    private String community;

    public String getCommunity() { return community;}
    public void setCommunity(String community) { this.community = community; }

    (... Overrides from INode ...)
}

NodeRepository:

@Repository
public interface NodeRepository extends JpaRepository { }

所以现在我可以做这样的事情:

@ContextConfiguration("classpath:/spring/application-context.xml")
@RunWith(SpringJUnit4ClassRunner.class)
public class NodeRepositoryTest {

    @Autowired
    NodeRepository repo;

    private INode node;

    @Before
    @Transactional
    @Rollback(false)
    public void setup() {
        node = new IPNode();
        node.setName("ipNode");
        node.setIpAddress("1.1.1.1");
        repo.save((IPNode)node);

        node = new SNMPNode();
        node.setName("snmpNode");
        node.setIpAddress("2.2.2.2");
        node.setCommunity("some text");
        repo.save((SNMPNode)node);
    }

    @Test
    @Transactional
    public void Test() throws Exception {
        INode testNode = repo.findOne(1L);
        assertNotNull(testNode);
    }
}

两种节点类型都保存在同一个表中,因此它们的密钥不能重复...我的REST URL可以通过/ nodes/1或/ nodes/2获取它们,这毕竟是我的主要目标......

谢谢 :)