JPA 1.0 错误：名称不是可识别的实体或标识符。已知实体名称：[]

Question

当我尝试执行简单的 JPA 1.0 代码时，出现以下异常。 可能是什么原因？

5453  DevPQRWDPBSSPersist  WARN   [P=351601:O=0:CT] openjpa.Enhance - This configuration disallows runtime optimization, but the following listed types were not enhanced at build time or at class load time with a javaagent: "[class com.XYZ.PQR.bss.client.db.data.markerentry, class com.XYZ.PQR.bss.client.db.data.Serviceproduct, class com.XYZ.PQR.bss.client.db.data.Agreementterms, class com.XYZ.PQR.bss.client.db.data.Offeringattribute, class com.XYZ.PQR.bss.client.db.data.marker, class com.XYZ.PQR.bss.client.db.data.OfferingpriceadjustmentrelPK, class com.XYZ.PQR.bss.client.db.data.Serviceoffering, class com.XYZ.PQR.bss.client.db.data.Offeringassociation, class com.XYZ.PQR.bss.client.db.data.OfferingpriceserviceofferingrelPK, class com.XYZ.PQR.bss.client.db.data.Offer, class com.XYZ.PQR.bss.client.db.data.Offeringpriceadjustmentrel, class com.XYZ.PQR.bss.client.db.data.Offeringfamily, class com.XYZ.PQR.bss.client.db.data.Offeringpriceserviceofferingrel, class com.XYZ.PQR.bss.client.db.data.Serviceproductattribute, class com.XYZ.PQR.bss.client.db.data.Offeringprice, class com.XYZ.PQR.bss.client.db.data.Agreement]".
6563  DevPQRWDPBSSPersist  TRACE  [P=351601:O=0:CT] openjpa.jdbc.SQL - <t 1183336072, conn 944453707> executing prepstmnt 152307988 SELECT so.* from DB2INST1.SERVICEOFFERING so where so.ISDELETED = 0 and so.id in (select oa.SERVICEOFFERINGID from DB2INST1.OFFERINGATTRIBUTE oa where oa.SERVICEOFFERINGID = so.id AND oa.name = ? and oa.STRINGVALUE = ? and oa.ISDELETED = 0) [params=(String) productbundleid, (String) attrValue]
7281  DevPQRWDPBSSPersist  TRACE  [P=351601:O=0:CT] openjpa.jdbc.SQL - <t 1183336072, conn 944453707> [718 ms] spent
Exception in thread "P=351601:O=0:CT" <openjpa-1.2.1-SNAPSHOT-r422266:686069 nonfatal user error> org.apache.openjpa.persistence.ArgumentException: An error occurred while parsing the query filter "SELECT OBJECT(attr) FROM Offeringattribute attr WHERE attr.serviceofferingid IN (:OfferingIds) AND attr.isdeleted = 0". Error message: The name "Offeringattribute" is not a recognized entity or identifier. Known entity names: []
 at org.apache.openjpa.kernel.exps.AbstractExpressionBuilder.parseException(AbstractExpressionBuilder.java:118)
 at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getClassMetaData(JPQLExpressionBuilder.java:180)
 at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.resolveClassMetaData(JPQLExpressionBuilder.java:150)
 at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateMetaData(JPQLExpressionBuilder.java:225)
 at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateMetaData(JPQLExpressionBuilder.java:195)
 at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateType(JPQLExpressionBuilder.java:188)
 at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.access$600(JPQLExpressionBuilder.java:69)
 at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder$ParsedJPQL.populate(JPQLExpressionBuilder.java:1756)
 at org.apache.openjpa.kernel.jpql.JPQLParser.populate(JPQLParser.java:56)
 at org.apache.openjpa.kernel.ExpressionStoreQuery.populateFromCompilation(ExpressionStoreQuery.java:153)
 at org.apache.openjpa.kernel.QueryImpl.newCompilation(QueryImpl.java:658)
 at org.apache.openjpa.kernel.QueryImpl.compilationFromCache(QueryImpl.java:639)
 at org.apache.openjpa.kernel.QueryImpl.compileForCompilation(QueryImpl.java:605)
 at org.apache.openjpa.kernel.QueryImpl.compileForExecutor(QueryImpl.java:667)
 at org.apache.openjpa.kernel.QueryImpl.getOperation(QueryImpl.java:1492)
 at org.apache.openjpa.kernel.DelegatingQuery.getOperation(DelegatingQuery.java:123)
 at org.apache.openjpa.persistence.QueryImpl.execute(QueryImpl.java:243)
 at org.apache.openjpa.persistence.QueryImpl.getResultList(QueryImpl.java:293)
 at com.XYZ.PQR.bss.client.offering.impl.OfferingServiceImpl.getOfferingsByStringAttribute(OfferingServiceImpl.java:661)
 at com.XYZ.PQR.bss.marker.impl.testAks.testAPI(testAks.java:38)
 at com.XYZ.PQR.bss.marker.impl.testAks.main(testAks.java:24)

    <properties>

<property name="openjpa.ConnectionDriverName" value="com.XYZ.db2.jcc.DB2Driver"/>
   <property name="openjpa.ConnectionURL" value="jdbc:db2://xyz.com:50000/ABC"/>
   <property name="openjpa.ConnectionUserName" value="usr"/>
   <property name="openjpa.ConnectionPassword" value="pwd"/>
   <property name="openjpa.jdbc.Schema" value="sch123"/>
    <property name="openjpa.Log" value="SQL=TRACE" />

</properties>

Answer 1

跟踪的第一行警告您，您的实体未在构建时或类加载时使用 javaagent 进行增强。

虽然我的理解是运行增强器并不是严格要求的，但跟踪的以下部分仍然暗示 OpenJPA 不知道任何实体：

错误消息：名称“Offeringattribute”不是可识别的实体或标识符。已知实体名称：[]

看起来好像出了问题和/或 OpenJPA 没有使用任何 后备机制。在日志中查找先前的警告。或者设置构建时间增强。

以下资源可能会有所帮助：

• 实体增强
• OpenJPA 用户指南
  • 第 2.增强

Answer 2

仔细阅读此内容 http://openjpa.apache.org/build-and-runtime -dependency.html

如果您的项目是独立应用程序，则必须将 geronimo-* 库添加到您的项目中。

Answer 3

我在使用旧版 JPA 1.0 Web 应用程序时间歇性地遇到此问题。这是由于实体增强之前发生的请求。

如果仍然卡在 JPA 1.0 应用程序上并且间歇性地遇到此问题，请尝试将以下内容添加到 persistence.xml：

来自 Open JPA 文档，第 6.2 章：元数据存储库：

预加载：布尔属性。如果为 true，OpenJPA 将立即加载
EntityManagerFactory 创建的存储库。结果，所有实体
类将被 JVM 急切地加载。一旦元数据预加载
完成后，所有锁定都会从 MetaDataRepository 中删除，并且此
将产生一个更具可扩展性的存储库。如果为假，则
当实体类被加载时，存储库将被延迟加载
JVM。默认值为 false。

此选项在 openjpa-1.2.1 (2009) 中不可用，但在 openjpa-1.2.3 发布时 (2013) 引入。