Karaf 4.0.0 M2、Hibernate 4.3.6 和 org.hibernate.PropertyAccessException答案

【问题标题】：Karaf 4.0.0 M2, Hibernate 4.3.6, and org.hibernate.PropertyAccessExceptionKaraf 4.0.0 M2、Hibernate 4.3.6 和 org.hibernate.PropertyAccessException
【发布时间】：2015-08-21 01:04:26
【问题描述】：

我正在关注 Christian Schneider 的 Karaf/Database 教程，网址如下： http://www.liquid-reality.de/display/liquid/2012/01/13/Apache+Karaf+Tutorial+Part+6+-+Database+Access

我对本教程的更改是使用 MySql 和 Hibernate 而不是 H2 和 OpenJpa。话虽如此，我可以加载我的自定义包，但是 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？

提前感谢您的任何建议。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>

persistence.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>

Person.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。

【问题讨论】：

你能把PersonServiceImpl.add()的代码发过来吗？
根据本文档docs.jboss.org/hibernate/orm/4.2/quickstart/en-US/html/…确认你的项目结构。根据文档 hibernate.properties 文件或 persistence.xml 应该在项目中
同意，我在项目中有 persistence.xml 文件，但没有 hibernate.properties 文件。似乎我可以在 hibernate.properties 中设置的任何配置也可以在 persistence.xml 中定义。所以在这方面一切都应该是好的。仍然不确定是什么导致对 Person 类的反射失败。
您确定在将person 添加到数据库时遇到此问题。因为我创建了一个运行完美的小型应用程序。
您能否通过在PersonServiceImpl.add() 应用断点并检查person 对象name 属性中的值来确定？

标签： hibernate karaf aries

【解决方案1】：

我已将原始帖子中列出的相同代码部署到 Apache Karaf 3.0.3 实例，并且代码运行良好。问题出在 Apache Karaf 4.0.0 M2，更具体地说是 Apache Aries v1.0.4。

如前所述，Aries 1.0.4 在 Karaf 4.0.0 M2 中启动时会生成以下警告

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.

此警告表明 Aries 现在在 blueprint.xml 文件中声明工件时遇到问题。

Christian Schneider 写了一篇文章，说明 Aries 现在如何使用注释来声明上下文： http://www.liquid-reality.de/display/liquid/New+design+for+aries+jpa

我还没有尝试过这些注释，但将让其他人确认 Aries 1.0.4（因此 Karaf 4.0.0）不再支持在 blueprint.xml 文件中声明上下文。

【讨论】：