1：数据库链接的URL问题
问 题关键出现在红色参数部分：jdbc:mysql://localhost:3306/hzzj?charsetEncoding=UTF8& amp;defaultFetchSize=100&useCursorFetch=true&defaultFetchSize=100
报错特征：
2012-05-11 10:19:08,328 WARN [com.mchange.v2.resourcepool.BasicResourcePool] - -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
java.sql.SQLException: java.lang.NullPointerException
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:904)
at com.mysql.jdbc.ServerPreparedStatement.executeInternal(ServerPreparedStatement.java:704)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
2012-05-11 10:19:08,390 WARN [org.hibernate.cfg.SettingsFactory] - Could not obtain connection metadata
java.sql.SQLException: Connections could not be acquired from the underlying database!
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:529)
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBeanCaused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1319)
at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)
解决方式：将红色参数去除即可
2：Struts2的struts.xml文件中包含其他文件时用的是*号
问题关键：<include file="struts*.xml"/>
报错特征：
<2012-5-11 上午10时31分48秒 CST> <Error> <HTTP> <BEA-101165> <Could not load user defined filter in web.xml: org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.
Unable to load configuration. - [unknown location]
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:58)
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:360)
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:403)
at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:69)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:48)
Truncated. see log file for complete stacktrace
Error loading configuration file struts.xml - [unknown location]
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments(XmlConfigurationProvider.java:148)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:111)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:164)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:55)
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:360)
Truncated. see log file for complete stacktrace
unable to attain an URLClassLoader - [unknown location]
at com.opensymphony.xwork2.util.ClassPathFinder.findMatches(ClassPathFinder.java:80)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:923)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments(XmlConfigurationProvider.java:144)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:111)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:164)
Truncated. see log file for complete stacktrace
>
解决方式：将<include file="struts*.xml"/>更改为如<include file="struts_system.xml"/>。
造成的原因如下：
xwork的ClassPathFinder.findMatches方法里取得当前classloader的方式是
ClassLoader loader = Thread.currentThread().getContextClassLoader()；在tomcat环境下取到的是 URLClassloader的实例，而在weblogic下面却是 weblogic.utils.classloaders.ChangeAwareClassLoader，weblogic有自己的 classLoader机制，因此导致了错误
3：Struts2的struts.xml文件中配置模式的参数问题
问题关键：<constant name="struts.devMode" value="true" />
报错特征：
<2012-5-11 上午10时35分17秒 CST> <Error> <HTTP> <BEA-101165> <Could not load user defined filter in web.xml: org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.
java.lang.NullPointerException
at com.opensymphony.xwork2.util.FileManager$FileRevision.needsReloading(FileManager.java:209)
at com.opensymphony.xwork2.util.FileManager.fileNeedsReloading(FileManager.java:60)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.needsReload(XmlConfigurationProvider.java:325)
at org.apache.struts2.config.StrutsXmlConfigurationProvider.needsReload(StrutsXmlConfigurationProvider.java:168)
at com.opensymphony.xwork2.config.ConfigurationManager.conditionalReload(ConfigurationManager.java:220)
Truncated. see log file for complete stacktrace
>
解决方式：将<constant name="struts.devMode" value="true" />更改为<constant name="struts.devMode" value="false" />
4：在做查询的时候，报出 org.hibernate.QueryException: ClassNotFoundException: org.hibernate.hql.ast.HqlToken这 个错误（是通过数据源连接的）
问题关键：Weblogic环境中缺失antlr.jar Jar包
报错特征：
netest Exception: org.hibernate.queryexception:classnotfindException:org.hibernate.hql.ast.HqlToken
解决方式：
A： 将如果你是通过Eclipse/Myeclipse启动weblogic的，那么依次点击windows-preferences-myeclipse workbench-servers-weblogic-weblogic10.x-path,在prepend to classpath选项中，把hibernate要用到的包antlr.jar添加到weblogic的classpath中。
这样在weblogic便可以通过myeclipse正常启动，以上提到的问题解决。
B：如果你是通过weblogic自带的脚本运行，即通过startWebLogic.cmd启动：
将 工程里的antlr.jar拷贝到weblogic的wlserver_10.3\server\lib文件夹下面，在domains \base_domain\bin里找到startWebLogic.cmd文件，在set classpath 的上下分别增加了两句话，如下： set PRE_CLASSPATH=%WL_HOME%\server\lib\antlr-2.7.6rc1.jar
set CLASSPATH=%SAVE_CLASSPATH%
set CLASSPATH=%PRE_CLASSPATH%;%CLASSPATH%
然后启动WebLogic，系统正常运行。
http://hi.baidu.com/shancunyefeng/item/30e93236708830342e0f812d