尝试连接到 derby 数据库，我收到以下错误：
Jan 17, 2014 2:05:36 PM org.hibernate.validator.internal.util.Version <clinit>
INFO: HV000001: Hibernate Validator 5.0.0.Final
[EL Info]: 2014-01-17 14:05:36.35--ServerSession(989603483)--EclipseLink, version: Eclipse Persistence Services - 2.5.1.v20130918-f2b9fc5
[EL Severe]: ejb: 2014-01-17 14:05:36.36--ServerSession(989603483)--Exception [EclipseLink-4003] (Eclipse Persistence Services - 2.5.1.v20130918-f2b9fc5): org.eclipse.persistence.exceptions.DatabaseException
Exception Description: Configuration error. Class [org.apache.derby.jdbc.ClientDriver] not found.
Exception in thread "main" javax.persistence.PersistenceException: Exception [EclipseLink-4003] (Eclipse Persistence Services - 2.5.1.v20130918-f2b9fc5): org.eclipse.persistence.exceptions.DatabaseException
Exception Description: Configuration error. Class [org.apache.derby.jdbc.ClientDriver] not found.
at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:766)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.getAbstractSession(EntityManagerFactoryDelegate.java:204)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.getDatabaseSession(EntityManagerFactoryDelegate.java:182)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.getDatabaseSession(EntityManagerFactoryImpl.java:527)
at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactoryImpl(PersistenceProvider.java:140)
at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:177)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39)
at com.mycompany.managingpersistanceobjects.App.main(App.java:20)
Caused by: Exception [EclipseLink-4003] (Eclipse Persistence Services - 2.5.1.v20130918-f2b9fc5): org.eclipse.persistence.exceptions.DatabaseException
Exception Description: Configuration error. Class [org.apache.derby.jdbc.ClientDriver] not found.
at org.eclipse.persistence.exceptions.DatabaseException.configurationErrorClassNotFound(DatabaseException.java:89)
at org.eclipse.persistence.sessions.DefaultConnector.loadDriverClass(DefaultConnector.java:267)
at org.eclipse.persistence.sessions.DefaultConnector.connect(DefaultConnector.java:85)
at org.eclipse.persistence.sessions.DatasourceLogin.connectToDatasource(DatasourceLogin.java:162)
at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.setOrDetectDatasource(DatabaseSessionImpl.java:204)
at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.loginAndDetectDatasource(DatabaseSessionImpl.java:741)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:239)
at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:685)
... 8 more
------------------------------------------------------------------------
BUILD FAILURE
------------------------------------------------------------------------
Total time: 1.590s
Finished at: Fri Jan 17 14:05:36 CET 2014
Final Memory: 5M/121M
------------------------------------------------------------------------
Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:exec (default-cli) on project ManagingPersistanceObjects: Command execution failed. Process exited with an error: 1 (Exit value: 1) -> [Help 1]
To see the full stack trace of the errors, re-run Maven with the -e switch.
Re-run Maven using the -X switch to enable full debug logging.
For more information about the errors and possible solutions, please read the following articles:
[Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
这是一个主类：
public class App {
public static void main(String[] args) {
Customer customer = new Customer("Anthony", "Balla", "[email protected]");
Address address = new Address("Rirherdon RD", "London", "8QE", "UK");
customer.setAddress(address);
EntityManagerFactory emf = Persistence.createEntityManagerFactory("chapter06PU");
EntityManager em = emf.createEntityManager();
EntityTransaction et = em.getTransaction();
et.begin();
em.persist(customer);
et.commit();
em.close();
emf.close();
}
}
这是持久性单元：
<?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="chapter06PU" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<properties>
<property name="javax.persistence.jdbc.url" value="jdbc:derby://localhost:1527/chapter06PU;create=true"/>
<property name="javax.persistence.jdbc.password" value="app"/>
<property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.ClientDriver"/>
<property name="javax.persistence.jdbc.user" value="app"/>
<property name="javax.persistence.schema-generation.database.action" value="drop-and-create"/>
</properties>
</persistence-unit>
</persistence>
数据库运行情况：
Fri Jan 17 10:37:31 CET 2014 : Security manager installed using the Basic server
security policy.
Fri Jan 17 10:37:31 CET 2014 : Apache Derby Network Server - 10.10.1.1 - (145826
8) started and ready to accept connections on port 1527
我相信我在 POM 中有对客户端的依赖：
<dependency>
<groupId>org.apache.derby</groupId>
<artifactId>derby</artifactId>
<version>10.10.1.1</version>
<type>jar</type>
</dependency>
你能给建议吗？
您只需使用 derbyclient 而不是 derby 作为artifactId：
<dependency>
<groupId>org.apache.derby</groupId>
<artifactId>derbyclient</artifactId>
<version>10.10.1.1</version>
<type>jar</type>
</dependency>
......
您需要在应用程序服务器中安装 derby 驱动程序安装程序才能使其正常工作。仅将其包含在您的应用程序本身中是不够的。
对于提出问题时的 Java 发行版，最简单的方法是告诉 JBoss 使用 JDK 而不是默认的 JRE，因为我相信 Derby 包含在 JDK 中。
表示未找到 JDBC 驱动程序。你把它纳入你的图书馆了吗？
您必须将 derbyclient.jar 复制到 Tomcat 服务器的 lib 文件夹中。
请参阅这个答案。