我一直 在使用MySQL在tomcat7上使用hibernate3 开发一个 struts Web应用程序 。起初我一直在使用c3p0 pooling …然后我切换到 tomcat pooling 。但是一天后，我得到了同样的错误。每天早晨，我们必须重新启动服务器。
日志显示java.lang.NullPointerException如下
java.lang.NullPointerException
sm.Login.execute(Login.java:24) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) java.lang.reflect.Method.invoke(Unknown Source) com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:452) com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:291) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:254) com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:263) org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:133) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:270) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:190) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) interceptors.SessionCheck.intercept(SessionCheck.java:47) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) interceptors.LoginInterceptor.intercept(LoginInterceptor.java:43) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52) org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:498) org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77) org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
我的META-INF / context.xml在这里，
<?xml version="1.0" encoding="UTF-8"?> <Context antiJARLocking="true" path="/sealmanagement"> RemoveAbandoned="true" maxAllowed="150" maxIdle="15" name="jdbc/stockdb" type="javax.sql.DataSource" factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" url="jdbc:mysql://localhost:3306/stockdb?autoReconnect=true" driverClassName="com.mysql.jdbc.Driver" username="root" password="1234" jmxEnabled="true" testWhileIdle="true" testOnBorrow="true" validationQuery="SELECT 1" testOnReturn="true" validationInterval="3000" timeBetweenEvictionRunsMillis="30000" maxActive="100" initialSize="10" maxWait="1000" minEvictableIdleTimeMillis="30000" minIdle="10" logAbandoned="true"
jdbcInterceptors =“ org.apache.tomcat.jdbc.pool.interceptor.ConnectionState; org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer”
/>
然后是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> <!-- using container-managed JNDI --> <property name="hibernate.connection.datasource"> java:comp/env/jdbc/stockdb </property> <property name="hibernate.dialect"> org.hibernate.dialect.MySQLDialect </property> <property name="hibernate.current_session_context_class">org.hibernate.context.ThreadLocalSessionContext</property>
package dbcon; import org.hibernate.cfg.AnnotationConfiguration; import org.hibernate.SessionFactory; /** * Hibernate Utility class with a convenient method to get Session Factory object. * * */ public class HibernateUtil { private static final SessionFactory sessionFactory; static { try { // Create the SessionFactory from standard (hibernate.cfg.xml) // config file. sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory(); } catch (Throwable ex) { // Log the exception. System.err.println("Initial SessionFactory creation failed." + ex); throw new ExceptionInInitializerError(ex); } } public static SessionFactory getSessionFactory() { return sessionFactory; } }
事件，尽管它不影响我也将PoolProperties类也放在Java代码中。可能是问题…
这是Getdbcon.java
package dbcon; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import org.apache.tomcat.jdbc.pool.DataSource; import org.apache.tomcat.jdbc.pool.PoolProperties; public class Getdbcon { //get mysql connection // -- shehan public Connection getmysqlConnection() throws SQLException { PoolProperties p = new PoolProperties(); p.setUrl("jdbc:mysql://localhost:3306/stockdb?auto_reconnect=true"); p.setDriverClassName("com.mysql.jdbc.Driver"); p.setUsername("root"); p.setPassword("1234"); p.setJmxEnabled(true); p.setTestWhileIdle(true); p.setTestOnBorrow(true); p.setValidationQuery("SELECT * from userlogin where 1 limit 1"); p.setTestOnReturn(true); p.setValidationInterval(30000); p.setTimeBetweenEvictionRunsMillis(30000); p.setMaxActive(100); p.setInitialSize(2); p.setMaxWait(10000); p.setMinEvictableIdleTimeMillis(30000); p.setMinIdle(10); p.setLogAbandoned(true); p.setRemoveAbandoned(false); p.setJdbcInterceptors("org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer"); DataSource datasource = new DataSource(); datasource.setPoolProperties(p); Connection con = null; try{ con = datasource.getConnection(); } catch(Exception e){ e.printStackTrace(); } return con; }
这里是tomcat启动日志控制台的一些代码…认为它们很有用
INFO: JDBC driver: MySQL-AB JDBC Driver, version: mysql-connector-java-5.1.6 ( Revision: ${svn.Revision} ) Mar 15, 2013 9:00:08 AM org.hibernate.dialect.Dialect <init> INFO: Using dialect: org.hibernate.dialect.MySQLDialect Mar 15, 2013 9:00:08 AM org.hibernate.transaction.TransactionFactoryFactory buildTransactionFactory INFO: Using default transaction strategy (direct JDBC transactions) Mar 15, 2013 9:00:08 AM org.hibernate.transaction.TransactionManagerLookupFactory getTransactionManagerLookup INFO: No TransactionManagerLookup configured (in JTA environment, use of read-write or transactional second-level cache is not recommended) Mar 15, 2013 9:00:08 AM org.hibernate.cfg.SettingsFactory buildSettings INFO: Automatic flush during beforeCompletion(): disabled Mar 15, 2013 9:00:08 AM org.hibernate.cfg.SettingsFactory buildSettings INFO: Automatic session close at end of transaction: disabled
请对此进行关注。非常感谢您。
然后，在 my.ini 的末尾添加了 wait_timeout 变量。并为其赋予最大值 根据这个 __
然后一切都解决了。那个问题不再困扰我了。
