卡拉夫和持久性单元：缺少依赖关系：JpaTemplate

Question

我正在争取安装JPA并在Karaf 4.0.8容器上启动持久性单元。我已经安装：

feature:install webconsole 
feature:repo-add mvn:org.apache.aries.jpa/jpa-features/2.5.0/xml/features 
feature:install jpa/2.5.0 
feature:install transaction-api/1.2.0 
feature:install transaction 
feature:install eclipselink 

我与持久性单元捆绑开始，但它并没有出口任何服务。使用它和进口的JpaTemplate束无法导入服务：

<reference id="jpaTemplate" interface="org.apache.aries.jpa.template.JpaTemplate" filter="(osgi.unit.name=officialUnit)" /> 

应该从我的持久性bundle导出，但事实并非如此。 'diag'显示持久性捆绑包没有问题。

如何调试持久单元未正确启动的原因？

我的persistence.xml看起来像这样：

<?xml version="1.0" encoding="UTF-8"?> 
<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" xmlns="http://java.sun.com/xml/ns/persistence"> 

    <persistence-unit name="officialUnit" transaction-type="JTA"> 
     <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider> 

     <!-- Only used when transaction-type=JTA --> 
     <jta-data-source>osgi:service/javax.sql.DataSource/(osgi.jndi.service.name=demo-db)</jta-data-source> 

     <!-- Only used when transaction-type=RESOURCE_LOCAL --> 
     <non-jta-data-source>osgi:service/javax.sql.DataSource/(osgi.jndi.service.name=demo-db)</non-jta-data-source> 

     <class>example.entity.SomeEntity</class>  

     <exclude-unlisted-classes>true</exclude-unlisted-classes> 
     <properties> 
      <property name="eclipselink.ddl-generation" value="none" /> 
      <property name="eclipselink.ddl-generation.output-mode" value="sql-script" /> 
     </properties> 

    </persistence-unit> 
</persistence> 

配置文件etc/org.ops4j.datasource-sqlitetest.cfg：

osgi.jdbc.driver.name=sqlite 
url=jdbc:sqlite:D:/data/db/demo.db 
dataSourceName=demo-db 

和持久性捆绑的MANIFEST.MF：

Manifest-Version: 1.0 
Bnd-LastModified: 1486560203107 
Build-Jdk: 1.8.0_121 
Bundle-Description: Persistence 
Bundle-ManifestVersion: 2 
Bundle-Name: example.persistence.impl 
Bundle-SymbolicName: example.persistence.impl 
Bundle-Version: 1.0.0.SNAPSHOT 
Created-By: Apache Maven Bundle Plugin 
Export-Package: example.persistence.impl;version="1.0.0";uses:="javax.pe 
rsistence,javax.xml.bind.annotation" 
Import-Package: javax.persistence;version="[2.1,3)",javax.xml.bind.annot 
ation 
Meta-Persistence: META-INF/persistence.xml 
Originally-Created-By: Apache Maven Bundle Plugin 
Provide-Capability: osgi.service;effective:=active;objectClass="org.apac 
he.aries.jpa.supplier.EmSupplier";osgi.unit.name=officialUnit,osgi.serv 
ice;effective:=active;objectClass="javax.persistence.EntityManagerFacto 
ry";osgi.unit.name=officialUnit,osgi.service;effective:=active;objectCl 
ass="org.apache.aries.jpa.template.JpaTemplate";osgi.unit.name=official 
Unit,osgi.service;effective:=active;objectClass="javax.persistence.Enti 
tyManager";osgi.unit.name=officialUnit 
Require-Capability: osgi.service;effective:=active;objectClass="javax.sq 
l.DataSource";filter:="(osgi.jndi.service.name=demo-db)",osgi.service;e 
ffective:=active;objectClass="javax.persistence.spi.PersistenceProvider 
";javax.persistence.provider="org.eclipse.persistence.jpa.PersistencePr 
ovider",osgi.extender;osgi.extender="aries.jpa",osgi.service;effective: 
=active;objectClass="javax.transaction.TransactionManager",osgi.ee;filt 
er:="(&(osgi.ee=JavaSE)(version=1.8))" 
Tool: Bnd-3.2.0.201605172007 

持久单元已成功使用OSGi Framework启动协议在Eclipse中启动成形。

Answer 1

因为有许多运动部件，Jpa并不是无关紧要的。第一步是检查你的持久性包是否被aries jpa容器找到。

首先要检查的是，如果Persitence单元包的Manifest具有Meta-Persistence头并指向persistence.xml，如：META-INF/persistence.xml。

如果你有这个，那么jpa容器应该拿起这个包并解析你的persistence.xml。

接下来要检查的是PersistenceProvider服务是否存在以及DataSource是否存在（如果使用的是DataSource）。

如果您使用的配置，然后不要忘记安装必要的PAX-JDBC功能配置您的数据源：

feature:repo-add pax-jdbc 1.0.0 
feature:install pax-jdbc-config pax-jdbc-sqlite