隨筆檔案

做一個web項目，啟動tomcat時遇到了這樣一個錯誤：

 嚴重: Exception loading sessions from persistent storage 
java.io.WriteAbortedException: writing aborted，java.io.NotSerializableException: ...

解決：對象要必須實現java.io.Serializable接口;

信息: Illegal access: this web application instance has been stopped already.  Could not load java.net.BindException.  The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
java.lang.IllegalStateException
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1244)
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)
 at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
 at com.mysql.jdbc.CommunicationsException.<init>(CommunicationsException.java:155)
 at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:2723)

解決辦法:
將tomcat的server.xml中的Context的reloadable設成false。
比如:<Context path="/expert" docBase="expert" debug="0" reloadable="false">

 

解決辦法也容易，只要把tomcat的server.xml 中的reloadable="true" 改成false就行了，不過這樣做就失去了熱部署的優勢了，對于開發不是很方便，干脆還是不改吧。這種錯誤不用理會.  

報錯原理：

 

原因是因為在tomcat重啟的時候，因為之前的tomcat中的線程還沒有完全關閉，新啟動tomcat就會報這個異常，不過這個不影響正常使用，只是跳個異常挺煩人的。使用過hibernate, spring或其他大型組件，當一個WEB應用系統中有很多類時，如果開啟了Tomcat的reloadable=true,那么每當相關文件改變時， Tomcat會停止web app并釋放內存,然后重新加載web app.這實在是個浩大的工程。所以我們總是在想如果能有只重載某幾個類的功能，將極大的滿足了我們的調試。

  當response.sendRedirect("xxxx");   時,而客戶端關閉了瀏覽器,就會出這種錯.    
  并非程序錯誤.

 

引自：http://blog.csdn.net/m232341339/archive/2008/11/01/3201104.aspx

出現了錯誤異常：
信息: Illegal access: this web application instance has been stopped already.  Could not load java.net.BindException.  The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
java.lang.IllegalStateException
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1273)
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233)
 at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
 at com.mysql.jdbc.SQLError.createLinkFailureMessageBasedOnHeuristics(SQLError.java:1220)
 at com.mysql.jdbc.CommunicationsException.<init>(CommunicationsException.java:51)
 at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1070)
 at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3270)
 at com.mysql.jdbc.MysqlIO.quit(MysqlIO.java:1659)
 at com.mysql.jdbc.ConnectionImpl.realClose(ConnectionImpl.java:4296)
 at com.mysql.jdbc.ConnectionImpl.cleanup(ConnectionImpl.java:1265)
 at com.mysql.jdbc.ConnectionImpl.finalize(ConnectionImpl.java:2667)
 at java.lang.ref.Finalizer.invokeFinalizeMethod(Native Method)
 at java.lang.ref.Finalizer.runFinalizer(Finalizer.java:83)
 at java.lang.ref.Finalizer.access$100(Finalizer.java:14)
 at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:160)

在啟動 tomcat ，并發布應用后沒有問題，但是如果重新發布就出現如下異常：

this web application instance has been stopped already. Could not load java.net.BindException

this web application instance has been stopped already. Could not load com.mysql.jdbc

這是由于 MySQL 的 JDBC 驅動放在應用的 WEB-INF\lib 目錄下，在重新發布時其加載了兩次，故只要將其拷貝到 TOMCAT_HOME%\lib 中即可解決該問題。

解決這兩個異常可以將 MySQL 的驅動文件從 WEB-INF\lib 文件夾中移動到 %TOMCAT_HOME%\lib 中。

 

引自：http://www.aygfsteel.com/cmzy/archive/2009/03/25/261884.html

出現的錯誤異常：
嚴重: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NoSuchMethodError: org.objectweb.asm.ClassVisitor.visit(IILjava/lang/String;Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;)V
Caused by: java.lang.NoSuchMethodError: org.objectweb.asm.ClassVisitor.visit(IILjava/lang/String;Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;)V

原因：spring和hibernate的包不兼容，asm.jar(hibernate)和asm-2.2.3.jar(spring)

解決辦法：將asm-2.2.3.jar刪除

今天晚上把三個框架整合在一起出現了一些異常：
log4j:WARN No appenders could be found for logger (org.springframework.web.context.ContextLoader).
log4j:WARN Please initialize the log4j system properly.
2009-7-25 0:31:38 org.apache.catalina.core.StandardContext filterStart
嚴重: Exception starting filter struts2
[unknown location]
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:835)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments(XmlConfigurationProvider.java:131)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:100)
 at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reload(DefaultConfiguration.java:130)
 at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:52)
 at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:395)
 at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:452)
 at org.apache.struts2.dispatcher.FilterDispatcher.init(FilterDispatcher.java:205)
 at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)
 at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397)
 at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)
 at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3709)
 at org.apache.catalina.core.StandardContext.start(StandardContext.java:4363)
 at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)
 at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)
 at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:525)
 at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:926)
 at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:889)
 at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:492)
 at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1149)
 at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311)
 at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
 at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)
 at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)
 at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
 at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
 at org.apache.catalina.core.StandardService.start(StandardService.java:516)
 at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
 at org.apache.catalina.startup.Catalina.start(Catalina.java:578)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
 at java.lang.reflect.Method.invoke(Method.java:585)
 at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
 at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
Caused by: Premature end of file. - [unknown location]
 at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:123)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:830)
 ... 34 more
Caused by: org.xml.sax.SAXParseException: Premature end of file.
 at org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
 at org.apache.xerces.util.ErrorHandlerWrapper.fatalError(Unknown Source)
 at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
 at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
 at org.apache.xerces.impl.XMLScanner.reportFatalError(Unknown Source)
 at org.apache.xerces.impl.XMLDocumentScannerImpl$DTDDispatcher.dispatch(Unknown Source)
 at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
 at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
 at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
 at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
 at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
 at javax.xml.parsers.SAXParser.parse(SAXParser.java:375)
 at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:121)
 ... 35 more
2009-7-25 0:31:38 org.apache.catalina.core.StandardContext start
嚴重: Error filterStart
2009-7-25 0:31:38 org.apache.catalina.core.StandardContext start
嚴重: Context [/ssh] startup failed due to previous errors
2009-7-25 0:31:38 org.apache.catalina.core.ApplicationContext log

使用log4j.properties 提示錯誤信息
2009-07-25 01:02:05 [org.springframework.web.context.ContextLoader]-[INFO] Root WebApplicationContext: initialization started
 2009-07-25 01:02:05 [org.springframework.web.context.support.XmlWebApplicationContext]-[INFO] Refreshing org.springframework.web.context.support.XmlWebApplicationContext@19bd735: display name [Root WebApplicationContext]; startup date [Sat Jul 25 01:02:05 CST 2009]; root of context hierarchy
 2009-07-25 01:02:05 [org.springframework.beans.factory.xml.XmlBeanDefinitionReader]-[INFO] Loading XML bean definitions from ServletContext resource [/WEB-INF/applicationContext.xml]
 2009-07-25 01:02:06 [org.springframework.web.context.support.XmlWebApplicationContext]-[INFO] Bean factory for application context [org.springframework.web.context.support.XmlWebApplicationContext@19bd735]: org.springframework.beans.factory.support.DefaultListableBeanFactory@146df77
 2009-07-25 01:02:06 [org.springframework.beans.factory.support.DefaultListableBeanFactory]-[INFO] Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@146df77: defining beans []; root of factory hierarchy
 2009-07-25 01:02:06 [org.springframework.web.context.ContextLoader]-[INFO] Root WebApplicationContext: initialization completed in 1469 ms
 2009-07-25 01:02:07 [com.opensymphony.xwork2.config.providers.XmlConfigurationProvider]-[INFO] Parsing configuration file [struts-default.xml]
 2009-07-25 01:02:07 [com.opensymphony.xwork2.config.providers.XmlConfigurationProvider]-[INFO] Parsing configuration file [struts-plugin.xml]
 2009-07-25 01:02:07 [com.opensymphony.xwork2.util.DomHelper]-[FATAL] Premature end of file. at (null:-1:-1)
 org.xml.sax.SAXParseException: Premature end of file.
2009-07-25 01:02:07 [org.springframework.web.context.support.XmlWebApplicationContext]-[INFO] Closing org.springframework.web.context.support.XmlWebApplicationContext@19bd735: display name [Root WebApplicationContext]; startup date [Sat Jul 25 01:02:05 CST 2009]; root of context hierarchy
 2009-07-25 01:02:07 [org.springframework.beans.factory.support.DefaultListableBeanFactory]-[INFO] Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@146df77: defining beans []; root of factory hierarchy
 

因為自己沒有把struts.xml的文件配置好，沒有引入struts-default.xml的原因。

//取fck內容的長度
function GetLength(str)
{
    var oEditor = FCKeditorAPI.GetInstance(str) ;
    var checkContent= oEditor.EditorDocument ;
    var contentLength ;

    if ( document.all )       
    {
        contentLength= checkContent.body.innerText.trim().length ;
    }
    else                   
    {
        var r = checkContent.createRange() ;
        r.selectNodeContents( checkContent.body ) ;
        contentLength= r.toString().trim().length ;
    }
return contentLength
}  

//判斷是不是為空
function CheckPost(){
    if(GetLength("content")<=0)    //content為FCKeditor在頁面所設的名字
    {
        alert('請輸入內容');       
        return false;
    }
}

//取fck內容
function GetContent(str)
{
     var oEditor = FCKeditorAPI.GetInstance(str) ;
     return oEditor.GetXHTML();
}  

//去掉字符串的空格
String.prototype.trim = function()
{
             return this.replace(/(^[\s]*)|([\s]*$)/g, "");
}

在使用jstl標簽的出現了這樣的異常：java.lang.NoSuchFieldError: deferredExpression
原因是：在lib目錄下出現了連個不同版本的jstl標簽。
解決方法：把就版本的jstl刪除就可以了啊！

     摘要:   閱讀全文

一、在項目中的配置：
             .在WebRoot/META-INF下建context.xml文件，注意必須在該目錄下：                  
                  <?xml version="1.0" encoding="UTF-8"?>
                            <Context reloadable="true" crossContext="true">
                               <Resource
                                   name="jdbc/項目名" ---------------必須為項目名，否則會有異常
                                   auth="Container"---------------------該項為不變項
                                   type="javax.sql.DataSource"---------該項為不變項
                                  driverClassName="com.mysql.jdbc.Driver"------------數據庫驅動名
                                  url="jdbc:mysql://localhost:3306/haotian?autoReconnect=true"---url
                                  username="root"---------------------------------------用戶名
                                  password="root"----------------------------------------密碼
                                  maxActive="10"   ----------------------------最大連接數
                                  maxIdle="5"     -------------------------------最大空閑連接數
                                  maxWait="-1"/>   ------------------最大等待毫秒數，-1為無限等待
                            </Context>
               在Tomcat6.0以后就不需要在web.xml中配置了：
                                 <resource-ref>
                                            <description>DB Connection</description>
                                             <res-ref-name>jdbc/blog</res-ref-name>
                                             <res-type>javax.sql.DataSource</res-type>
                                             <res-auth>Container</res-auth>
                                   </resource-ref>


二、配置過程中遇到的異常及解決方法：
      (1)org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'
        解決方法：連接池的名字是name="jdbc/項目名"
     
      (2)org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver'

        解決方法：必須把mysql的驅動包，拷貝到tomcat/lib目錄下
   
     (3)javax.naming.NameNotFoundException: Name jdbc is not bound in this Context
         這個異常可能是使用tomcat6版本以下，需要在項目的web.xml配置：
                                        <resource-ref>
                                            <description>DB Connection</description>
                                             <res-ref-name>jdbc/blog</res-ref-name>
                                             <res-type>javax.sql.DataSource</res-type>
                                             <res-auth>Container</res-auth>
                                   </resource-ref>

以上是個人在開發過程中遇到的異常，在參考網友提供解決及個人實踐總結所得。