java - 阻止 Hibernate 在每次启动时尝试重新创建索引

Question

我打开了启动时架构自动更新。一切都很顺利，但有一件事:在每次启动时，我的架构中的每个索引都会出现以下异常(大约有一百个)。显然 Hibernate 要么无法检测到索引已经存在，要么根本没有尝试检测到这一点，我该如何解决这个问题？它会破坏日志文件，并且很难注意到是否真的出了问题。

03:35:45,553 WARN  [AnnotationSessionFactoryBean:1119] Unsuccessful schema statement: create index statusIndex on Application (status)
org.postgresql.util.PSQLException: ERROR: relation "statusindex" already exists
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2103)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1836)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:512)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:374)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeUpdate(AbstractJdbc2Statement.java:302)
at org.apache.commons.dbcp.DelegatingStatement.executeUpdate(DelegatingStatement.java:228)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.executeSchemaStatement(LocalSessionFactoryBean.java:1115)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.executeSchemaScript(LocalSessionFactoryBean.java:1087)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean$1.doInHibernate(LocalSessionFactoryBean.java:942)
at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:406)
at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:339)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.updateDatabaseSchema(LocalSessionFactoryBean.java:935)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.afterSessionFactoryCreation(LocalSessionFactoryBean.java:883)
at org.springframework.orm.hibernate3.AbstractSessionFactoryBean.afterPropertiesSet(AbstractSessionFactoryBean.java:190)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1514)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1452)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:591)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:469)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:383)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:283)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:111)
at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:548)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:136)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:156)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.jetty.Server.doStart(Server.java:224)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.xml.XmlConfiguration.main(XmlConfiguration.java:985)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.mortbay.start.Main.invokeMain(Main.java:194)
at org.mortbay.start.Main.start(Main.java:534)
at org.mortbay.start.Main.start(Main.java:441)
at org.mortbay.start.Main.main(Main.java:119)

Answer 1

好吧，这并不是问题的直接答案，因为我忘了提及我也使用 Spring，但是我们要替换的类仍然在堆栈跟踪中提到。

一年后，当我最初问这个问题时，我又回到了我一直在从事的项目。异常仍然存在，没有人费心去处理它们，但这一次它们真的搞乱了我的调试。当我打开 AnnotationSessionFactoryBean 源代码并查找 #executeSchemaStatement() (位于其父 LocalSessionFactoryBean 中)时，我发现了以下 javadoc:

    /**
 * Execute the given schema SQL on the given JDBC Statement.
 * <p>Note that the default implementation will log unsuccessful statements
 * and continue to execute. Override this method to treat failures differently.
 * @param stmt the JDBC Statement to execute the SQL on
 * @param sql the SQL statement to execute
 * @throws SQLException if thrown by JDBC methods (and considered fatal)
 */

因此，“重写此方法以不同方式处理失败。”

基本上就是这样。我已经对 AnnotationSessionFactoryBean 进行了子类化并重写了该方法:

public class IndexErrorWrappingSessionFactoryBean extends AnnotationSessionFactoryBean {
@Override
protected void executeSchemaStatement(Statement stmt, String sql) throws SQLException {
    if (logger.isDebugEnabled()) {
        logger.debug("Executing schema statement: " + sql);
    }
    try {
        stmt.executeUpdate(sql);
    }
    catch (SQLException ex) {
        if (logger.isWarnEnabled()) {
            if (ex instanceof PSQLException
                    && sql.startsWith("create index")
                    && ex.getMessage() != null
                    && ex.getMessage().endsWith("already exists")) {
                logger.warn("Unsuccessful schema statement: " + sql + " (index already exists)");
            } else {
                logger.warn("Unsuccessful schema statement: " + sql, ex);
            }
        }
    }
}

}

现在我的输出中不再有那些垃圾了。