异常[EclipseLink-4003](Eclipse Persistence Services - 2.3.0.v20110604-r9504):

Question

当我的Web项目尝试连接数据库时,我收到异常.

Exception [EclipseLink-4003] (Eclipse Persistence Services - 2.3.0.v20110604-r9504): org.eclipse.persistence.exceptions.DatabaseException Exception Description: Configuration error. Class [com.mysql.jdbc.Driver] not found.at org.eclipse.persistence.exceptions.DatabaseException.configurationErrorClassNotFound(DatabaseException.java:82)

我的persistence.xml是这样的:

<?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="flashpoll">
<class>entities.Question</class>
<class>entities.Poll</class>
<class>entities.User</class>
<class>entities.Answers</class>
<class>entities.Admin</class>
<properties>
        <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/flashpoll"/>
        <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
        <property name="javax.persistence.jdbc.password" value="12345"/>
        <property name="javax.persistence.jdbc.user" value="root" />
        <property name="eclipselink.ddl-generation" value="create-tables" />
        <property name="eclipselink.persistence-context.flush-mode" value="COMMIT" />
    </properties>
</persistence-unit>
</persistence>

mysql-connector-5.0.8也包含在项目的库中.知道为什么我仍然收到这个类[com.mysql.jdbc.Driver]找不到错误？谢谢你的帮助.

Answer 1

创建Web应用程序时,应将库(jar)放在WEB-INF/lib文件夹中,以便Web应用程序服务器(Tomcat,JBoss,GlassFish等)识别.只需将您的mysql驱动程序和其他第三方库复制/粘贴到此文件夹中,然后重新部署您的应用程序.