找不到类[org.apache.derby.jdbc.ClientDriver]。尝试连接到db时 [英] Class [org.apache.derby.jdbc.ClientDriver] not found. When trying to connect to db

问题描述

我在Netbeans中设置了一个项目，创建了一个脚本，使用javadb创建了一个新的数据库。我可以通过gui连接到它 - 显示表内容等，但是当我运行一个应用程序：

I have set up a project in Netbeans, created a script, made a new database with javadb. I can connect to it by gui - display the tables contents etc, but when i run an application with:

 EntityManager em = Persistence.createEntityManagerFactory("lab5PU").createEntityManager();

我得到这个很长的例外：

i get this quite long exception:

[EL Info]: 2013-04-05 21:40:45.554--ServerSession(1198260109)--EclipseLink, version: Eclipse Persistence Services - 2.3.0.v20110604-r9504
[EL Severe]: 2013-04-05 21:40:45.574--ServerSession(1198260109)--Local Exception Stack: 
Exception [EclipseLink-4003] (Eclipse Persistence Services - 2.3.0.v20110604-r9504): org.eclipse.persistence.exceptions.DatabaseException
Exception in thread "AWT-EventQueue-0" javax.persistence.PersistenceException: Exception [EclipseLink-4003] (Eclipse Persistence Services - 2.3.0.v20110604-r9504): org.eclipse.persistence.exceptions.DatabaseException
Exception Description: Configuration error.  Class [org.apache.derby.jdbc.ClientDriver] not found.
Exception Description: Configuration error.  Class [org.apache.derby.jdbc.ClientDriver] not found.
    at org.eclipse.persistence.exceptions.DatabaseException.configurationErrorClassNotFound(DatabaseException.java:82)

我可以看到在服务驱动程序部分的javadb驱动程序，所以我不知道错误可能是什么。

I can see the javadb drivers in the driver section in services, so i have no idea what the error might be.

编辑：persistance.xml请求： / p>

persistance.xml as requested:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/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">
  <persistence-unit name="lab5PU" transaction-type="RESOURCE_LOCAL">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <class>lab5.Colleagues</class>
    <properties>
      <property name="javax.persistence.jdbc.url" value="jdbc:derby://localhost:1527/lab5"/>
      <property name="javax.persistence.jdbc.password" value="mypass"/>
      <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.ClientDriver"/>
      <property name="javax.persistence.jdbc.user" value="admin"/>
      <property name="eclipselink.ddl-generation" value="create-tables"/>
    </properties>
  </persistence-unit>
</persistence>

推荐答案

我认为你的问题是你没有Derby驱动

I think the problem you have is that you don't have the Derby driver in the classpath of the project.

您可以轻松地实现将JavaDB库添加到您的项目：

You can easily achieve that adding the JavaDB library to your project:

• 右键单击项目


• 属性 - >库


• 添加库 - > JavaDB驱动程序

这包括 derby.jar ， derbyclient.jar

This includes derby.jar, derbyclient.jar and derbynet.jar in your project's classpath.

derbyclient.jar 包含类 org.apache.derby.jdbc.ClientDriver 您的代码正在抱怨。

The derbyclient.jar contains the class org.apache.derby.jdbc.ClientDriver your code is complaining about.

这篇关于找不到类[org.apache.derby.jdbc.ClientDriver]。尝试连接到db时的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！