Hibernate / MySQL connection timeout

Question

Hibernate / MySQL connection timeout

I wrote a server application that supports a website and several mobile clients. I used Hibernate to access the data. Later I discovered that the application does not work in a day! When I checked online, I found out that his well-known problem with MySQL ends with an “outdated” connection after 8 hours. To avoid this, I found many suggestions, such as ?autoReconnect=true, using c3P0, etc. Since autoReconnectI am officially discouraged (especially in the production environment), and also because it had no effect when I applied it, I decided to go for it c3P0. Unfortunately, after entering the configuration c3P0in my file, the hibernate.cfg.xmlapplication starts throwing NullPointerExceptionsomewhere in my code where I called. dbSession.close() This means thatHibernateUtil.getSessionFactory()actually returns null. I added the necessary banks (c3p0-0.9.2-pre2.jar, hibernate-core-3.3.1.GA.jar, hibernate-c3p0-3.3.2.GA.jar, mchange-commons-java-0.2.1.jar and c3p0-oracle-thin-extras-0.9.2-pre2.jar), although I don't think they are all required. I looked through many pages that talked about this problem, but I still cannot configure it correctly. Please help me with the "beginner-friendly" easy-to-use step-by-step setup procedure c3P0with Hibernate. I am using Hibernate 3.3.6 on JDK 1.6, MySQL 5.5, and I am developing in Netbeans 7.0.

Here is my hibernate.cfg.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">
<hibernate-configuration>
  <session-factory>
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/religion_app</property>
    <property name="hibernate.connection.username">*****</property>
    <property name="hibernate.connection.password">*****</property>
    <property name="hibernate.show_sql">true</property>
    <property name="hibernate.current_session_context_class">thread</property>
    <property name="hibernate.query.factory_class">org.hibernate.hql.classic.ClassicQueryTranslatorFactory</property>

    <property name="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>
    <property name="connection.autoReconnect">true</property>
    <property name="connection.autoReconnectForPools">true</property>
    <property name="connection.is-connection-validation-required">true</property>

    <!-- configuration pool via c3p0-->
    <property name="c3p0.acquire_increment">1</property> 
    <property name="c3p0.idle_test_period">120</property> <!-- seconds --> 
    <property name="c3p0.max_size">100</property> 
    <property name="c3p0.max_statements">0</property> 
    <property name="c3p0.min_size">10</property> 
    <property name="c3p0.timeout">180</property> <!-- seconds -->
    <property name="c3p0.preferredTestQuery">select 1;</property>

    <!--Mappings go here-->
  </session-factory>
</hibernate-configuration>

Here is what I got after adding c3p0 (without slf4j):

    May 23, 2012 2:42:14 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet LoginChurch threw exception
java.lang.NullPointerException
    at com.pacesolutions.religionapp.services.LoginChurch.processRequest(LoginChurch.java:109)
    at com.pacesolutions.religionapp.services.LoginChurch.doPost(LoginChurch.java:138)
    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.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    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.Http11AprProcessor.process(Http11AprProcessor.java:859)
    at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
    at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
    at java.lang.Thread.run(Thread.java:722)

May 23, 2012 2:45:13 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet LoginChurch threw exception
java.lang.ClassNotFoundException: org.slf4j.LoggerFactory
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1516)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1361)
    at org.hibernate.connection.C3P0ConnectionProvider.<clinit>(C3P0ConnectionProvider.java:52)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
    at java.lang.Class.newInstance0(Class.java:372)
    at java.lang.Class.newInstance(Class.java:325)
    at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:73)
    at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:56)
    at org.hibernate.cfg.SettingsFactory.createConnectionProvider(SettingsFactory.java:414)
    at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:62)
    at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2009)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1292)
    at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:859)
    at com.pacesolutions.religionapp.HibernateUtil.<clinit>(HibernateUtil.java:23)
    at com.pacesolutions.religionapp.services.LoginChurch.processRequest(LoginChurch.java:68)
    at com.pacesolutions.religionapp.services.LoginChurch.doPost(LoginChurch.java:143)
    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.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    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.Http11AprProcessor.process(Http11AprProcessor.java:859)
    at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
    at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
    at java.lang.Thread.run(Thread.java:722)


    note The full stack trace of the root cause is available in the Apache Tomcat/6.0.26 logs.

Hibernate, Netbeans. , Hibernate Netbeans , . , c3p0 ( 8 ). Mecurial , c3p0, ( 8 ). c3p0 hibernate.cfg.xml . ?

+5

java mysql hibernate connection-pooling c3p0

Sayo Oladeji 22 '12 2:25

3

Nayan Wadekar · Answer 1 · 2012-05-22T05:45:37+0000

, C3P0, c3p0-0.9.2-pre2.jar mchange-commons-java-0.2.1.jar. , c3p0.properties classpath.

, C3P0 Hibernate.

hibernate.cfg.xml

<property name="connection.provider_class">
                org.hibernate.connection.C3P0ConnectionProvider</property>
<property name="hibernate.c3p0.acquire_increment">1</property> 
<property name="hibernate.c3p0.idle_test_period">100</property>
<property name="hibernate.c3p0.max_size">100</property> 
<property name="hibernate.c3p0.max_statements">100</property> 
<property name="hibernate.c3p0.min_size">10</property> 
<property name="hibernate.c3p0.timeout">180</property>

c3p0.properties

c3p0.testConnectionOnCheckout=true, .
, .
c3p0.acquireRetryAttempts = 4
c3p0.acquireRetryDelay = 5000
4 5 .

Steve Waldman · Answer 2 · 2012-05-23T17:26:17+0000

c3p0 SLF4J. , , .

NPE, , . ( c3p0.)

, c3p0.properties CLASSPATH , , . c3p0.properties ClassLoader.

Sayo oladeji · Answer 3 · 2012-05-23T11:46:16+0000

, . c3p0 , @NayanWadekar. , c3p0 SLF4J. , c3p0 , SLF4J . , SLF4J , , . , Netbeans, SLF4J , at slf4.org. The reason is that some of the cans are not intended for sharing in one project. Just use the following libraries from the library: slf4j-api-1.6.4.jar and slf4j-jdk14-1.6.4.jar. See www.slf4j.org for more details .

Hibernate / MySQL connection timeout

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