PROSAGA码农传奇-SF服务编织-ClassNotFoundException：尝试加载类时检测到的循环

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    我喜欢这个解决方案，这不是一个解决方案，而是一个替代方案。我决定使用EclipseLink 2.6.4（使用持久性2.1），并在pom.xml和persistence.xml上进行一些小的更改，我能够启动我的包。
考虑到我还在使用Karaf 4.1（Apache Felix）和Aries（JPA和Blueprint），我相信这个问题可能与我不再使用的库相关：OpenJPA（最有可能）或Geronimo JPA（ JSR-317）。
  
  
    对不起，现在没有足够的时间在OpenJPA上找到解决这个问题的方法，但我很着急。我希望这个解决方案可以帮助其他人解决同样的问题。
  
  
    这是我当前的pom.xml（我添加了Jackson的库依赖项，因为我在我的服务中执行了一些JSON转换，你可能不需要）：
  
   <pre>
 <code>
 <?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

<parent>
 <artifactId>xxx.persistence</artifactId>
 <groupId>bse.persistence</groupId>
 <version>1.0.0-SNAPSHOT</version>
 </parent>

<groupId>bse.jpa</groupId>
 <artifactId>zzz.yyy</artifactId>
 <packaging>bundle</packaging>

<name>bse.jpa Bundle</name>
 <description>zzz.yyy OSGi bundle project.</description>

<dependency>
 <groupId>org.osgi</groupId>
 <artifactId>org.osgi.core</artifactId>
 <version>${osgi.version}</version>
 <scope>provided</scope>
 </dependency>
 <dependency>
 <groupId>org.osgi</groupId>
 <artifactId>osgi.cmpn</artifactId>
 <version>${osgi.version}</version>
 </dependency>
 <dependency>
 <groupId>org.osgi</groupId>
 <artifactId>osgi.enterprise</artifactId>
 <version>${osgi.version}</version>
 </dependency>

<dependency>
 <groupId>mysql</groupId>
 <artifactId>mysql-connector-java</artifactId>
 <version>5.1.34</version>
 </dependency>
 <dependency>
 <groupId>javax.annotation</groupId>
 <artifactId>javax.annotation-api</artifactId>
 <version>1.3.1</version>
 </dependency>
 <dependency>
 <groupId>commons-collections</groupId>
 <artifactId>commons-collections</artifactId>
 <version>3.2.2</version>
 </dependency>
 <dependency>
 <groupId>commons-lang</groupId>
 <artifactId>commons-lang</artifactId>
 <version>2.6</version>
 </dependency>

<dependency>
 <groupId>com.fasterxml.jackson.core</groupId>
 <artifactId>jackson-annotations</artifactId>
 <version>2.8.7</version>
 <type>bundle</type>
 </dependency>
 <dependency>
 <groupId>com.fasterxml.jackson.core</groupId>
 <artifactId>jackson-core</artifactId>
 <version>2.8.7</version>
 <type>bundle</type>
 </dependency>

<dependency>
 <groupId>org.eclipse.persistence</groupId>
 <artifactId>javax.persistence</artifactId>
 <version>2.1.0</version>
 </dependency>
 <dependency>
 <groupId>org.eclipse.persistence</groupId>
 <artifactId>eclipselink</artifactId>
 <version>2.6.4</version>
 </dependency>
 <dependency>
 <groupId>org.eclipse.persistence</groupId>
 <artifactId>org.eclipse.persistence.antlr</artifactId>
 <version>2.6.4</version>
 </dependency>
 <dependency>
 <groupId>org.eclipse.persistence</groupId>
 <artifactId>org.eclipse.persistence.asm</artifactId>
 <version>2.6.4</version>
 </dependency>
 <dependency>
 <groupId>org.eclipse.persistence</groupId>
 <artifactId>org.eclipse.persistence.jpa.jpql</artifactId>
 <version>2.6.4</version>
 </dependency>
 <dependency>
 <groupId>org.eclipse.persistence</groupId>
 <artifactId>org.eclipse.persistence.core</artifactId>
 <version>2.6.4</version>
 </dependency>
 <dependency>
 <groupId>org.eclipse.persistence</groupId>
 <artifactId>org.eclipse.persistence.jpa</artifactId>
 <version>2.6.4</version>
 </dependency>
 <dependency>
 <groupId>org.eclipse.persistence</groupId>
 <artifactId>
 org.eclipse.persistence.jpa.modelgen.processor
 </artifactId>
 <version>2.6.4</version>
 </dependency>
 </dependencies>

<build>
 <resources>
 <resource>
 <directory>src/main/java</directory>
 <excludes>
 <exclude>**/*.java</exclude>
 </excludes>
 </resource>
 <resource>
 <directory>src/main/resources</directory> 
 </resource> 
 </resources>
 <pluginManagement>
 <plugins>
 <plugin>
 <groupId>org.apache.felix</groupId>
 <artifactId>maven-bundle-plugin</artifactId>
 <version>${maven-bundle-plugin.version}</version>
 <extensions>true</extensions>
 <configuration>
 <archive>
 <manifestEntries>
 <Meta-Persistence>META-INF/persistence.xml</Meta-Persistence>
 <Bundle-Blueprint>OSGI-INF/blueprint/*.xml</Bundle-Blueprint>
 </manifestEntries>
 </archive> 
 <manifestLocation>src/main/resources/META-INF</manifestLocation>
 <rebuildBundle>true</rebuildBundle>
 <instructions>
 <Bundle-SymbolicName>${project.artifactId}</Bundle-SymbolicName>
 <Bundle-Version>${project.version}</Bundle-Version>
 <Bundle-Activator>bse.jpa.Activator</Bundle-Activator>
 <Import-Package>com.mysql.jdbc.jdbc2.optional,
 org.apache.felix.service.command,
 org.apache.karaf.shell.commands,
 org.apache.karaf.shell.console,
 org.eclipse.persistence.internal.weaving,
 org.eclipse.persistence.internal.descriptors,
 org.eclipse.persistence.queries,
 org.eclipse.persistence.descriptors.changetracking,
 org.eclipse.persistence.internal.identitymaps,
 org.eclipse.persistence.sessions,
 org.eclipse.persistence.internal.jpa.rs.metadata.model,
 org.eclipse.persistence.indirection, 
 javax.sql, 
 javax.persistence;version=2.0, 
 javax.persistence.metamodel,
 javax.transaction,
 javax.transaction.xa, 
 org.osgi.framework,
 org.osgi.util.tracker,
 *</Import-Package>
 <Export-Package>cbn.bse.jpa.persistence.entities,
 bse.jpa
 </Export-Package> 
 <Meta-Persistence>META-INF/persistence.xml</Meta-Persistence>
 <Bundle-ManifestVersion>2</Bundle-ManifestVersion>
 <Include-Resource>src/main/resources</Include-Resource>
 <Bundle-Blueprint>OSGI-INF/blueprint/*.xml</Bundle-Blueprint>

</instructions>
 </configuration>
 </plugin>
 <plugin>
 <groupId>org.apache.maven.plugins</groupId>
 <artifactId>maven-compiler-plugin</artifactId>
 <configuration>
 <source>1.8</source>
 <target>1.8</target>
 <maxmem>256M</maxmem>
 </configuration>
 </plugin>

<plugin>
 <groupId>org.bsc.maven</groupId>
 <artifactId>maven-processor-plugin</artifactId>
 <version>2.2.4</version>
 <executions>
 <execution>
 <id>eclipselink-jpa-metamodel</id>
 <goals>
 <goal>process</goal>
 </goals>
 <phase>generate-sources</phase>
 <configuration>
 <processors>
 <processor>org.eclipse.persistence.internal.jpa.modelgen.CanonicalModelProcessor</processor>
 </processors>
 <compilerArguments>-Aeclipselink.persistencexml=${basedir}/src/test/resources/META-INF/persistence.xml</compilerArguments>
 <outputDirectory>${project.build.directory}/generated-sources</outputDirectory>
 </configuration>
 </execution>
 </executions>
 <dependencies>
 <dependency>
 <groupId>org.eclipse.persistence</groupId>
 <artifactId>org.eclipse.persistence.jpa.modelgen.processor
 </artifactId>
 <version>2.6.4</version>
 </dependency>
 </dependencies>
 </plugin>

<plugin>
 <artifactId>maven-assembly-plugin</artifactId>
 <executions>
 <execution>
 <goals>
 <goal>assembly</goal>
 </goals>
 </execution>
 </executions>
 </plugin>

</plugins>
 </pluginManagement>
 </build>
</project>

</code>
 </pre>
  
    持久性（您可以将其更改为使用JTA与pax-jdbc-mysql轻松实现）：
  
   <pre>
 <code>
 <?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" 
 xmlns="http://xmlns.jcp.org/xml/ns/persistence"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
 <persistence-unit name="rrrr" transaction-type="RESOURCE_LOCAL">
 <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
 <non-jta-data-source>osgi:service/javax.sql.DataSource/(osgi.jndi.service.name=jdbc/rrrr)</non-jta-data-source>
 <class>Account</class>
 <class>Warehouse</class>
 <class>Widget</class>
 <exclude-unlisted-classes>true</exclude-unlisted-classes>
 <properties>
 <property name="eclipselink.logging.level" value="WARNING"/>
 <property name="eclipselink.logging.level.sql" value="WARNING"/>
 <property name="eclipselink.logging.parameters" value="true"/>
 <property name="eclipselink.logging.timestamp" value="true"/>
 <property name="eclipselink.logging.session" value="true"/>
 <property name="eclipselink.logging.thread" value="true"/>
 <property name="eclipselink.logging.exceptions" value="true"/>
 <property name="eclipselink.session.include.descriptor.queries" value="true"/>
 <property name="eclipselink.weaving" value="true"/>

</properties>
 </persistence-unit>
</persistence>

</code>
 </pre>
  
    有用的参考：
  
  
    <a href="https://github.com/lburgazzoli/lb-karaf-examples-jpa/tree/master/jpa-eclipselink-25" rel="nofollow noreferrer">
      Luca Burgazzoli的Karaf例子（jpa）
    </A>
  
  
    <a href="https://github.com/endeavor85/endeavor85.github.io/wiki/EclipseLink-JPA-Metamodel-Generation-in-Eclipse-with-Maven" rel="nofollow noreferrer">
      Travis Steel使用Maven在Eclipse中生成EclipseLink JPA元模型
    </A>
  
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ClassNotFoundException：尝试加载类时检测到的循环 - 在实体类中（在Karaf中启动JPA包时）