在earlier post中，我的hibernate配置文件存在一些未知问题。一个人给了我另一个配置文件使用，并解决了旧的配置错误。之后，我删除了这些评论附近的代码 - “！ - 禁用缓存 - ”“！ - UTF8到数据库 - ”“！ - 实体映射 - ”现在我收到一个新错误。< / strong>但它也引入了一个新的错误，如下所示。我该如何解决？
org.hibernate.cfg.annotations.Version <clinit>
INFO: Hibernate Annotations 3.3.1.GA
[main] INFO org.hibernate.cfg.Environment - Hibernate 3.3.2.GA
[main] INFO org.hibernate.cfg.Environment - hibernate.properties not found
[main] INFO org.hibernate.cfg.Environment - Bytecode provider name : javassist
[main] INFO org.hibernate.cfg.Environment - using JDK 1.4 java.sql.Timestamp handling
[main] INFO org.hibernate.cfg.Configuration - configuring from resource: /hibernate.cfg.xml
[main] INFO org.hibernate.cfg.Configuration - Configuration resource: /hibernate.cfg.xml
[main] INFO org.hibernate.cfg.Configuration - Configured SessionFactory: null
[main] INFO org.hibernate.dialect.Dialect - Using dialect: org.hibernate.dialect.MySQLDialect
Apr 17, 2013 3:10:39 AM org.hibernate.cfg.AnnotationBinder bindClass
INFO: Binding entity from annotated class: com.examscam.model.User
Apr 17, 2013 3:10:39 AM org.hibernate.cfg.annotations.EntityBinder bindTable
INFO: Bind entity com.examscam.model.User on table User
Apr 17, 2013 3:10:39 AM org.hibernate.cfg.AnnotationConfiguration secondPassCompile
INFO: Hibernate Validator not found: ignoring
[main] INFO org.hibernate.tool.hbm2ddl.SchemaExport - Running hbm2ddl schema export
[main] INFO org.hibernate.tool.hbm2ddl.SchemaExport - exporting generated schema to database
[main] INFO org.hibernate.connection.ConnectionProviderFactory - Initializing connection provider: org.hibernate.connection.C3P0ConnectionProvider
[main] INFO org.hibernate.connection.C3P0ConnectionProvider - C3P0 using driver: com.mysql.jdbc.Driver at URL: jdbc:mysql://127.0.0.1:3306/test
[main] INFO org.hibernate.connection.C3P0ConnectionProvider - Connection properties: {useUnicode=true, user=root, password=****, characterEncoding=UTF-8}
[main] INFO org.hibernate.connection.C3P0ConnectionProvider - autocommit mode: false
Exception in thread "main" java.lang.NoClassDefFoundError: com/mchange/v2/c3p0/DataSources
at org.hibernate.connection.C3P0ConnectionProvider.configure(C3P0ConnectionProvider.java:176)
at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:137)
at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:79)
at org.hibernate.tool.hbm2ddl.ManagedProviderConnectionHelper.prepare(ManagedProviderConnectionHelper.java:51)
at org.hibernate.tool.hbm2ddl.SchemaExport.execute(SchemaExport.java:252)
at org.hibernate.tool.hbm2ddl.SchemaExport.create(SchemaExport.java:211)
at com.examscam.model.User.persist(User.java:48)
at com.examscam.model.User.main(User.java:55)
Caused by: java.lang.ClassNotFoundException: com.mchange.v2.c3p0.DataSources
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 8 more
XML -
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<!-- Generated by MyEclipse Hibernate Tools. -->
<hibernate-configuration>
<session-factory>
<property name="dialect">
org.hibernate.dialect.MySQLDialect
</property>
<property name="connection.url">
correct url
</property>
<property name="connection.username">root</property>
<property name="connection.password">password</property>
<property name="connection.driver_class">
com.mysql.jdbc.Driver
</property>
</session-factory>
</hibernate-configuration>
答案 0 :(得分：2)
将此jar添加c3p0-0.9.1.1.jar到您的类路径。
像com.mchange.v2.c3p0.DataSources这样的接缝这个类在你的类路径中不存在。
答案 1 :(得分：2)
原因是项目库中没有c3p0.jar click to download，并将zip文件中的c3p0-0.9.x.jar放入项目lib目录中。没关系。
答案 2 :(得分：0)
请注意c3p0的新版本，我下载了最新版本（c3p0-0.9.5-pre9），我在其他错误中遇到了几个小时：
org.apache.catalina.core.StandardWrapperValve invoke GRAVE: Servlet.service()
for servlet default threw exception java.lang.ClassNotFoundException:
java.lang.AutoCloseable at org.apache.catalina.loader.WebappClassLoader.loadClass
或
java.lang.ClassNotFoundException: com.mchange.v2.c3p0.DataSources
我建议下载：c3p0-0.9.1并将所有jar导入您的项目。
答案 3 :(得分：0)
我刚做了一个干净的构建，这个问题就消失了。日食堆错误后发生在我身上。我不得不重新运行eclipse，杀死tomcat进程。