Hibernate-找不到适用于jdbc的驱动程序：mysql // *

Question

我正在尝试在Web项目引用的Java项目中运行hibernate模式。足够简单，除了无法hibernate以连接到数据库。我有很多人描述这个问题并获得大量答案，但是似乎没有一个对我有用。

这就是我的 hibernate.cfg.xml的 样子：

<?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">

<hibernate-configuration>
<session-factory>
    <!-- Database connection settings -->
     <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
     <property name="hibernate.connection.url">jdbc:mysql//localhost:3306/dbname</property>
     <property name="hibernate.connection.username">root</property>
     <property name="hibernate.connection.password">commander</property>

     <!-- JDBC connection pool (use the built-in) -->
    <property name="connection.pool_size">50</property>

    <!-- SQL dialect -->
    <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

    <!-- Enable Hibernate's automatic session context management -->
    <property name="current_session_context_class">thread</property>

    <!-- Enable the second-level cache  -->
    <property name="cache.provider_class">org.hibernate.cache.EhCacheProvider</property>

    <!-- Echo all executed SQL to stdout -->
    <property name="show_sql">true</property>

    <!-- Drop and re-create the database schema on startup -->
    <property name="hbm2ddl.auto">update</property>

    <mapping resource="com/amakena/profile/mapping/Credentials.hbm.xml"/>
    <mapping resource="com/amakena/profile/mapping/Profile.hbm.xml"/>
    <mapping resource="com/amakena/profile/mapping/City.hbm.xml"/>
    <mapping resource="com/amakena/profile/mapping/Country.hbm.xml"/>
    <mapping resource="com/amakena/profile/mapping/Gender.hbm.xml"/>
</session-factory>
</hibernate-configuration>

我将代码调试为 DriverManagerConnectionProvider 类，尝试使用 getConnection（） 方法会引发异常

Connection conn = DriverManager.getConnection(url, connectionProps);

我检查了url和connectionProps，它们是hibernate.cfg.xml中的

我在tomcat \ lib文件夹中添加了 mysql-connector-java-3.1.14-bin
，我可以在Eclipse中的Libraries> Apache Tomcat v6.0>下看到它。我也将它添加到我的％Javahome％\ lib \
ext和我的CLASSPATH变量中（我知道这是绝望的，这是没用的）。

我通过在 session.beginTransaction（） 之前运行以下代码来确保我的驱动程序已正确安装，这反过来导致
DriverManagerConnectionProvider.getConnection（）

Class.forName("com.mysql.jdbc.Driver");
Properties connectionProperties = new Properties();
connectionProperties.put("user", "root");
connectionProperties.put("password", "root");
DriverManager.getConnection("jdbc:mysql://localhost:3306/dbname", connectionProperties);

我注意到发出第一行会导致相同的异常。

抛出异常

WARNING: Method execution failed: 
org.hibernate.exception.JDBCConnectionException: Cannot open connection
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:99)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:52)
at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:449)
at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:160)
at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:81)
at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1473)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at     org.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:345)
at $Proxy0.beginTransaction(Unknown Source)
at com.amakena.profile.dao.CredentialsDao.hydrate(CredentialsDao.java:45)
at com.amakena.profile.ProfileManager.login(ProfileManager.java:19)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.directwebremoting.impl.ExecuteAjaxFilter.doFilter(ExecuteAjaxFilter.java:34)
at org.directwebremoting.impl.DefaultRemoter$1.doFilter(DefaultRemoter.java:428)
at org.directwebremoting.impl.DefaultRemoter.execute(DefaultRemoter.java:431)
at org.directwebremoting.impl.DefaultRemoter.execute(DefaultRemoter.java:283)
at org.directwebremoting.servlet.PlainCallHandler.handle(PlainCallHandler.java:52)
at org.directwebremoting.servlet.UrlProcessor.handle(UrlProcessor.java:101)
at org.directwebremoting.servlet.DwrServlet.doPost(DwrServlet.java:146)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)

Caused by: java.sql.SQLException: No suitable driver found for jdbc:mysql//localhost:3306/dbname
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at org.hibernate.connection.DriverManagerConnectionProvider.getConnection(DriverManagerConnectionProvider.java:133)
at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
... 37 more
WARNING: --Erroring: batchId[24] message[org.hibernate.exception.JDBCConnectionException: Cannot open connection]

我感谢我能得到的所有帮助。提前致谢。

使用的版本：Tomcat v6.0-Hibernate 3.6.6-Java 6-Eclipse 3.5.2 R35x

Answer 1

您在“ mysql”之后忘记了冒号：

 <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/dbname</property>

这是URL格式的文档：

jdbc:mysql://[host][,failoverhost...][:port]/[database]

没有合适的驱动程序 总是意味着已加载驱动程序JAR，但是您的URL语法不正确。