我在以下网址关注 Christian Schneider 的 Karaf/Database 教程： http ://www.liquid-reality.de/display/liquid/2012/01/13/Apache+Karaf+Tutorial+Part+6+-+数据库+访问
我对本教程的更改是使用 MySql 和 Hibernate 而不是 H2 和 OpenJpa。话虽如此，我让我的自定义包加载，但 Hibernate 无法使用反射来访问我的实体类中的属性。我得到的堆栈跟踪如下。
我的一些具体问题是：
- 我是否需要一个 hibernate.properties 文件，因为 persistence.xml 文件引用了数据源并允许设置休眠属性
- 我的 pom.xml 文件中是否有我需要的其他依赖项
- 是否有其他与 pom.xml 或 hibernate.properties 无关的原因导致下面显示的异常？
在此先感谢您的任何建议。兰迪
2015-06-05 16:40:04,088 | ERROR | nsole user karaf | ShellUtil | 41 - org.apache.karaf.shell.core - 4.0.0.M2 | Exception caught while executing command
java.lang.reflect.UndeclaredThrowableException
at com.sun.proxy.$Proxy72.persist(Unknown Source)[146:org.apache.aries.jpa.container.context:1.0.4]
at net.lr.tutorial.karaf.db.examplejpa.impl.PersonServiceImpl.add(PersonServiceImpl.java:23)[167:leonard-orm-native:1.0.0]
at Proxyead5dc4a_ed6c_46e9_8aad_e93af2278046.add(Unknown Source)[:]
at net.lr.tutorial.karaf.db.examplejpa.command.AddPersonCommand.execute(AddPersonCommand.java:42)[167:leonard-orm-native:1.0.0]
at org.apache.karaf.shell.commands.basic.AbstractCommand.execute(AbstractCommand.java:34)[41:org.apache.karaf.shell.core:4.0.0.M2]
at org.apache.karaf.shell.compat.CommandTracker$1.execute(CommandTracker.java:109)[41:org.apache.karaf.shell.core:4.0.0.M2]
at org.apache.karaf.shell.impl.console.osgi.secured.SecuredCommand.execute(SecuredCommand.java:67)[41:org.apache.karaf.shell.core:4.0.0.M2]
at org.apache.karaf.shell.impl.console.osgi.secured.SecuredCommand.execute(SecuredCommand.java:87)[41:org.apache.karaf.shell.core:4.0.0.M2]
at org.apache.felix.gogo.runtime.Closure.executeCmd(Closure.java:480)[41:org.apache.karaf.shell.core:4.0.0.M2]
at org.apache.felix.gogo.runtime.Closure.executeStatement(Closure.java:406)[41:org.apache.karaf.shell.core:4.0.0.M2]
at org.apache.felix.gogo.runtime.Pipe.run(Pipe.java:108)[41:org.apache.karaf.shell.core:4.0.0.M2]
at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:182)[41:org.apache.karaf.shell.core:4.0.0.M2]
at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:119)[41:org.apache.karaf.shell.core:4.0.0.M2]
at org.apache.felix.gogo.runtime.CommandSessionImpl.execute(CommandSessionImpl.java:94)[41:org.apache.karaf.shell.core:4.0.0.M2]
at org.apache.karaf.shell.impl.console.ConsoleSessionImpl.run(ConsoleSessionImpl.java:267)[41:org.apache.karaf.shell.core:4.0.0.M2]
at java.lang.Thread.run(Thread.java:745)[:1.7.0_60-ea]
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)[:1.7.0_60-ea]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)[:1.7.0_60-ea]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)[:1.7.0_60-ea]
at java.lang.reflect.Method.invoke(Method.java:606)[:1.7.0_60-ea]
at org.apache.aries.jpa.container.context.transaction.impl.JTAEntityManagerHandler.invoke(JTAEntityManagerHandler.java:185)[146:org.apache.aries.jpa.container.context:1.0.4]
... 16 more
Caused by: java.lang.reflect.UndeclaredThrowableException
at com.sun.proxy.$Proxy76.persist(Unknown Source)
... 21 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)[:1.7.0_60-ea]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)[:1.7.0_60-ea]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)[:1.7.0_60-ea]
at java.lang.reflect.Method.invoke(Method.java:606)[:1.7.0_60-ea]
at org.apache.aries.jpa.container.impl.EntityManagerProxyFactory$EMHandler.invoke(EntityManagerProxyFactory.java:31)
... 22 more
Caused by: javax.persistence.PersistenceException: org.hibernate.PropertyAccessException: could not get a field value by reflection getter of net.lr.tutorial.karaf.db.examplejpa.Person.name
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1763)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1677)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1683)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:1187)
... 27 more
Caused by: org.hibernate.PropertyAccessException: could not get a field value by reflection getter of net.lr.tutorial.karaf.db.examplejpa.Person.name
at org.hibernate.property.DirectPropertyAccessor$DirectGetter.get(DirectPropertyAccessor.java:60)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.getIdentifier(AbstractEntityTuplizer.java:346)
at org.hibernate.persister.entity.AbstractEntityPersister.getIdentifier(AbstractEntityPersister.java:4746)
at org.hibernate.persister.entity.AbstractEntityPersister.isTransient(AbstractEntityPersister.java:4465)
at org.hibernate.engine.internal.ForeignKeys.isTransient(ForeignKeys.java:243)
at org.hibernate.event.internal.AbstractSaveEventListener.getEntityState(AbstractSaveEventListener.java:511)
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:116)
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:75)
at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:811)
at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:784)
at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:789)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:1181)
... 27 more
Caused by: java.lang.IllegalArgumentException: Can not set java.lang.String field net.lr.tutorial.karaf.db.examplejpa.Person.name to net.lr.tutorial.karaf.db.examplejpa.Person
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:164)[:1.7.0_60-ea]
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:168)[:1.7.0_60-ea]
at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:55)[:1.7.0_60-ea]
at sun.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:36)[:1.7.0_60-ea]
at java.lang.reflect.Field.get(Field.java:379)[:1.7.0_60-ea]
at org.hibernate.property.DirectPropertyAccessor$DirectGetter.get(DirectPropertyAccessor.java:57)
... 38 more
蓝图.xml
xsi:schemaLocation="
http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0
http://www.w3.org/2001/XMLSchema-instance http://www.w3.org/2001/XMLSchema-instance
http://aries.apache.org/xmlns/jpa/v1.0.0 http://aries.apache.org/xmlns/jpa/v1.0.0
http://aries.apache.org/xmlns/transactions/v1.0.0 http://aries.apache.org/xmlns/transactions/v1.0.0 ">
<bean id="personService" class="net.lr.tutorial.karaf.db.examplejpa.impl.PersonServiceImpl">
<jpa:context unitname="Leonard" property="entityManager" />
<tx:transaction method="*" value="Required" />
</bean>
<service ref="personService" interface="net.lr.tutorial.karaf.db.examplejpa.PersonService" />
<command-bundle xmlns="http://karaf.apache.org/xmlns/shell/v1.0.0">
<command name="person/add">
<action class="net.lr.tutorial.karaf.db.examplejpa.command.AddPersonCommand">
<property name="personService" ref="personService" />
</action>
</command>
<command name="person/list">
<action class="net.lr.tutorial.karaf.db.examplejpa.command.ListPersonsCommand">
<property name="personService" ref="personService" />
</action>
</command>
<command name="person/deleteAll">
<action class="net.lr.tutorial.karaf.db.examplejpa.command.DeleteAllPersonsCommand">
<property name="personService" ref="personService" />
</action>
</command>
</command-bundle>
持久性.xml
<?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="Leonard" transaction-type="JTA">
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<jta-data-source>osgi:service/Leonard</jta-data-source>
<class>net.lr.tutorial.karaf.db.examplejpa.Person</class>
<exclude-unlisted-classes>true</exclude-unlisted-classes>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
</properties>
</persistence-unit>
</persistence>
人.java
package net.lr.tutorial.karaf.db.examplejpa;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "Person")
public class Person
{
private String name;
private String twitterName;
public Person()
{
}
public Person(String name, String twitterName)
{
super();
this.name = name;
this.twitterName = twitterName;
}
@Id
@Column(name = "name", unique = true)
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
@Column(name = "twitterName")
public String getTwitterName()
{
return twitterName;
}
public void setTwitterName(String twitterName)
{
this.twitterName = twitterName;
}
}
pom.xml
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>info.leonard.orm</groupId>
<artifactId>leonard-orm-native</artifactId>
<version>1.0.0</version>
<packaging>bundle</packaging>
<properties>
<log4j-version>1.2.16</log4j-version>
<slf4j-version>1.6.1</slf4j-version>
</properties>
<dependencies>
<dependency>
<groupId>org.apache.karaf.shell</groupId>
<artifactId>org.apache.karaf.shell.console</artifactId>
<version>4.0.0.M2</version>
</dependency>
<dependency>
<groupId>org.osgi</groupId>
<artifactId>org.osgi.core</artifactId>
<version>4.3.1</version>
</dependency>
<dependency>
<groupId>org.osgi</groupId>
<artifactId>org.osgi.enterprise</artifactId>
<version>4.2.0</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j-version}</version>
</dependency>
<dependency>
<groupId>org.hibernate.javax.persistence</groupId>
<artifactId>hibernate-jpa-2.1-api</artifactId>
<version>1.0.0.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.3.6.Final</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-osgi</artifactId>
<version>4.3.6.Final</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>4.3.6.Final</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.hibernate.common</groupId>
<artifactId>hibernate-commons-annotations</artifactId>
<version>4.0.4.Final</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.35</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.7</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>${log4j-version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>${slf4j-version}</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<finalName>${project.artifactId}</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.felix</groupId>
<artifactId>maven-bundle-plugin</artifactId>
<version>2.5.3</version>
<extensions>true</extensions>
<configuration>
<instructions>
<Bundle-SymbolicName>${project.artifactId}</Bundle-SymbolicName>
<Meta-Persistence>META-INF/persistence.xml</Meta-Persistence>
<Import-Package>
org.apache.felix.service.command;version="[0.6,1)",
org.apache.felix.gogo.commands;version="[0.6,1)",
org.apache.karaf.shell.console;version="[2.2,4)",
*,
org.hibernate.jpa,
org.hibernate.proxy,
javassist.util.proxy
</Import-Package>
</instructions>
</configuration>
</plugin>
</plugins>
</build>
</project>
PersonServiceImpl.java
package net.lr.tutorial.karaf.db.examplejpa.impl;
import java.util.List;
import javax.persistence.EntityManager;
import net.lr.tutorial.karaf.db.examplejpa.Person;
import net.lr.tutorial.karaf.db.examplejpa.PersonService;
public class PersonServiceImpl implements PersonService
{
private EntityManager em;
public void setEntityManager(EntityManager em)
{
this.em = em;
}
public void add(Person person)
{
em.persist(person);
em.flush();
}
public void deleteAll()
{
em.createQuery("delete from Person").executeUpdate();
em.flush();
}
public List<Person> getAll()
{
return em.createQuery("select p from Person p", Person.class).getResultList();
}
}
我重新启动了我的 karaf 实例，并查看了启动时的日志。以下项目引起了我的注意：
2015-06-06 04:17:02,988 | WARN | FelixStartLevel | aries | 144 - org.apache.aries.jpa.blueprint.aries - 1.0.4 | Managed persistence context support is no longer available for use with the Aries Blueprint container.
请注意，我的示例是使用容器管理的 JPA。看起来很奇怪，这实际上不受支持，但会在周末尝试非托管 JPA 实现。