org.hibernate.exception.JDBCConnectionException: Cannot open connection
连接数据库MySql, 经常出现以下错误, 但网页一般刷新几次后,又连接上数据库,可正常显示了.
以前没有出现过这种情况, 我在自己的电脑上调试时, 也没出现. 我的数据库连接配置文件是:
WEB-INF/classes/hibernate.cfg.xml, c3p0的连接池,
<?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 name="kh_session">
<!-- mysql connection -->
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<!-- jdbc:mysql://localhost/kh -->
<property name="hibernate.connection.url">
jdbc:mysql://www.070707zx.com/mydb
</property>
<property name="hibernate.connection.username">myname</property>
<property name="hibernate.connection.password">mypassword</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="show_sql">false</property>
<!-- C3P0 Connection Pool -->
<property name="hibernate.connection.provider_class">
org.hibernate.connection.C3P0ConnectionProvider
</property>
<property name="hibernate.c3p0.max_size">50</property>
<property name="hibernate.c3p0.min_size">2</property>
<property name="hibernate.c3p0.timeout">5000</property>
<property name="hibernate.c3p0.max_statements">100</property>
<property name="hibernate.c3p0.idle_test_period">3000</property>
<property name="hibernate.c3p0.acquire_increment">2</property>
<property name="hibernate.c3p0.maxIdleTime">1800</property >
<property name="hibernate.c3p0.validate">true</property>
<property name="hibernate.c3p0.preferredTestQuery">SELECT id FROM test WHERE id=1</property>
<mapping resource="kh3.hbm.xml" />
</session-factory>
</hibernate-configuration>
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下面是错误信息
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HTTP Status 500 -
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type Exception report
message
descript_ion The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: Cannot open connection
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:372)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.util.UrlFilter.doFilter(UrlFilter.java:64)
com.util.EncodingFilter.doFilter(EncodingFilter.java:114)
root cause
org.hibernate.exception.JDBCConnectionException: Cannot open connection
org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74)
org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29)
org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:426)
org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:144)
org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:139)
org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1547)
org.hibernate.loader.Loader.doQuery(Loader.java:673)
org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236)
org.hibernate.loader.Loader.doList(Loader.java:2220)
org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104)
org.hibernate.loader.Loader.list(Loader.java:2099)
org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:378)
org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:338)
org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:172)
org.hibernate.impl.SessionImpl.list(SessionImpl.java:1121)
org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
com.util.DBHelper.getQueryList(DBHelper.java:34)
com.mykh.YmcsHelper.getYmcs(YmcsHelper.java:29)
org.apache.jsp.index_jsp._jspService(index_jsp.java:89)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.util.UrlFilter.doFilter(UrlFilter.java:64)
com.util.EncodingFilter.doFilter(EncodingFilter.java:114)
note The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.
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请大家帮我看看