带有带有ElementCollection的HBase的DataNucleus / Kundera - 无法找到具有空id的对象

时间：2013-04-03 07:17:24

标签： java sql hbase datanucleus kundera

首先，我使用HBase 0.94.5（也尝试了0.92.2，结果相同）。

我有这样的情况：

变量类： 

@Entity
@Table(name = "variable", schema = "keyspace@hbase-pu")
public class Variable {
    @Id
    private String Id;

    @Column(name = "Name")
    private String Name;

    @ElementCollection(fetch = FetchType.EAGER)
   //@CollectionTable(name = "datavalues") // Doesn't work with or without.
    private List<DataValue> DataValues;

    // Getters and setters omitted.
}

DataValue类： 

@Embeddable
public class DataValue {
    @Column(name = "Value")
    private Object Value;

    // Getters and setters omitted.
}

现在，存储这个根本不是问题，但是当我想要检索它时，繁荣就是炸药。抛出此异常：

引起：org.datanucleus.exceptions.NucleusUserException：无法找到空id的对象！ 

Exception in thread "main" javax.persistence.PersistenceException: Unable to find the object with a null id!
    at org.datanucleus.api.jpa.NucleusJPAHelper.getJPAExceptionForNucleusException(NucleusJPAHelper.java:414)
    at org.datanucleus.api.jpa.JPAQuery.getResultList(JPAQuery.java:203)
    at Main.main(Main.java:73)
Caused by: org.datanucleus.exceptions.NucleusUserException: Unable to find the object with a null id!
    at org.datanucleus.ExecutionContextImpl.findObject(ExecutionContextImpl.java:3441)
    at org.datanucleus.store.hbase.fieldmanager.FetchFieldManager.fetchObjectField(FetchFieldManager.java:287)
    at org.datanucleus.state.JDOStateManager.replacingObjectField(JDOStateManager.java:2178)
    at Variable.jdoReplaceField(Variable.java)
    at Variable.jdoReplaceFields(Variable.java)
    at org.datanucleus.state.JDOStateManager.replaceFields(JDOStateManager.java:3415)
    at org.datanucleus.state.JDOStateManager.replaceFields(JDOStateManager.java:3442)
    at org.datanucleus.store.hbase.query.HBaseQueryUtils$2.fetchFields(HBaseQueryUtils.java:270)
    at org.datanucleus.state.JDOStateManager.loadFieldValues(JDOStateManager.java:2547)
    at org.datanucleus.state.JDOStateManager.initialiseForHollow(JDOStateManager.java:298)
    at org.datanucleus.state.ObjectProviderFactoryImpl.newForHollow(ObjectProviderFactoryImpl.java:89)
    at org.datanucleus.ExecutionContextImpl.newObjectProviderForHollowPopulated(ExecutionContextImpl.java:1237)
    at org.datanucleus.ExecutionContextImpl.findObject(ExecutionContextImpl.java:3053)
    at org.datanucleus.store.hbase.query.HBaseQueryUtils.getObjectUsingApplicationIdForResult(HBaseQueryUtils.java:265)
    at org.datanucleus.store.hbase.query.HBaseQueryUtils.getObjectsOfType(HBaseQueryUtils.java:194)
    at org.datanucleus.store.hbase.query.HBaseQueryUtils.getObjectsOfCandidateType(HBaseQueryUtils.java:93)
    at org.datanucleus.store.hbase.query.JPQLQuery.performExecute(JPQLQuery.java:327)
    at org.datanucleus.store.query.Query.executeQuery(Query.java:1786)
    at org.datanucleus.store.query.Query.executeWithMap(Query.java:1690)
    at org.datanucleus.api.jpa.JPAQuery.getResultList(JPAQuery.java:186)
    ... 1 more

这是因为ElementCollection，因为当我删除它时，它完全从HBase中检索变量类。我也尝试过Kundera 2.4（相同的示例代码），这比这个DataNucleus'增强'更容易设置，但是它会抛出一些Stream异常。两个站点都显示了与我上面的代码类似的代码示例，所以我非常好奇我在这里做错了。

相关的pom.xml：

    <dependency>
        <groupId>org.apache.geronimo.specs</groupId>
        <artifactId>geronimo-jpa_2.0_spec</artifactId>
        <version>1.1</version>
    </dependency>

    <dependency>
        <groupId>javax.jdo</groupId>
        <artifactId>jdo-api</artifactId>
        <version>3.0</version>
    </dependency>

   <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-core</artifactId>
        <version>3.2.1</version>
    </dependency>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-api-jpa</artifactId>
        <version>3.2.0-release</version>
    </dependency>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-hbase</artifactId>
        <version>3.2.0-release</version>
    </dependency>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-enhancer</artifactId>
        <version>3.1.1</version>
    </dependency>
    <dependency>
        <groupId>javax.persistence</groupId>
        <artifactId>persistence-api</artifactId>
        <version>2.0</version>
    </dependency>
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-core</artifactId>
        <version>1.1.2</version>
        <exclusions>
            <exclusion>
                <groupId>org.codehaus.jackson</groupId>
                <artifactId>jackson-mapper-asl</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.codehaus.jackson</groupId>
                <artifactId>jackson-core-asl</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.apache.hbase</groupId>
        <artifactId>hbase</artifactId>
        <version>0.94.5</version>
    </dependency>


        <plugin>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-maven-plugin</artifactId>
            <version>3.2.0-release</version>
            <configuration>
                <api>JPA</api>
                <persistenceUnitName>hbase-pu</persistenceUnitName>
                <verbose>true</verbose>
            </configuration>
            <executions>
                <execution>
                    <phase>process-classes</phase>
                    <goals>
                        <goal>enhance</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>

DataNucleus的persistance.xml：

    <persistence 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" version="2.0">

    <!-- JPA tutorial "unit" -->
    <persistence-unit name="hbase-pu" transaction-type="RESOURCE_LOCAL">
        <provider>org.datanucleus.api.jpa.PersistenceProviderImpl</provider>
        <class>Variable</class>
        <class>DataValue</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>
        <properties>
            <property name="datanucleus.storeManagerType" value="hbase" />
            <property name="datanucleus.ConnectionURL" value="hbase:localhost:2281"/>
            <property name="datanucleus.ConnectionUserName" value=""/>
            <property name="datanucleus.ConnectionPassword" value=""/>
            <property name="datanucleus.autoCreateSchema" value="true"/>
            <property name="datanucleus.autoCreateTables" value="true" />
            <property name="datanucleus.autoCreateColumns" value="true" />
            <property name="datanucleus.validateTables" value="true"/>
            <property name="datanucleus.validateConstraints" value="false"/>
            <property name="datanucleus.Optimistic" value="false"/>
            <property name="datanucleus.Multithreaded" value="true" />
        </properties>
    </persistence-unit>
</persistence>

昆德拉的persistence.xml：

<persistence 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
https://raw.github.com/impetus-opensource/Kundera/Kundera-2.0.4/kundera-core/src/test/resources/META-INF/persistence_2_0.xsd"
version="2.0">
 <persistence-unit name="hbase-pu">
        <provider>com.impetus.kundera.KunderaPersistence</provider>
        <properties>
            <property name="kundera.nodes" value="localhost" />
            <property name="kundera.port" value="2182" />
            <property name="kundera.keyspace" value="keyspace" />
            <property name="kundera.dialect" value="hbase" />
            <property name="kundera.client.lookup.class" value="com.impetus.client.hbase.HBaseClientFactory" />
        <property name="kundera.cache.provider.class" value="com.impetus.kundera.cache.ehcache.EhCacheProvider" />
        <property name="kundera.cache.config.resource" value="/ehcache-test.xml" />
        <property name="kundera.ddl.auto.prepare" value="update" />
        </properties>
    </persistence-unit>
</persistence>

我有点在这里用空白拍摄空白，我有一种感觉，我现在几乎尝试了所有事情，并且不知道如何继续。

- 请参阅下面的评论。

新变量类： 

@Entity
@Table(name = "variable", schema = "keyspace@hbase-pu")
public class Variable {
    @Id
    private String Id;

    @Column(name = "Name")
    private String Name;

    @ElementCollection(fetch = FetchType.EAGER) 
    private List<Object> DataValues;

    @Column(name = "Value")
    @Lob
    private Object Value;
    // Getters and setters omitted.
}

1 个答案:

答案 0 :(得分：1)

所以你想拥有一个嵌入式系列？但是作为this page shows clearly enough，目前HBi不支持这种方式（支持MongoDB，但是那时它具有更灵活的数据存储结构以允许它）。您可以拥有非实体的集合（与所有者持久保存在同一个HTable中），并且您可以拥有（非嵌入式）实体的集合，但不能拥有嵌入式集合。显然，如果它对你很重要，你可以贡献你的时间来提供支持（我甚至会在代码中为你提供起点）。

没有理由“CollectionTable”应该有所作为......它是模式的RDBMS的注释（但是JPA仅为RDBMS设计）。

PS 1，这个“增强功能”就像在pom.xml中添加“插件”块一样简单。因此，除非你准备好向DataNucleus项目表达 你的困难是什么，那么他们怎么知道呢。

PS 2，如果报告问题，我希望你能够显示异常+堆栈跟踪，无论涉及什么软件，因为从异常消息中你很少告诉别人。

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