為什么我的項目中出現“ java.lang.ClassNotFoundException”錯誤

Question

我不知道為什么這個錯誤會出現在我的項目中，所以你們是我最后的機會：

在我的項目中，我收到“ java.lang.ClassNotFoundException”異常。您能告訴我它背后的原因是什么。

when I am trying to run this program I am getting this message"
  HTTP status 404
INSIDE the console I am getting this error

如果您能給我一些提示，將不勝感激...

非常感謝，

  SEVERE: Error configuring application listener of class org.apache.struts2.tiles.StrutsTilesListener
java.lang.ClassNotFoundException: org.apache.struts2.tiles.StrutsTilesListener
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:415)
at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:397)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:118)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4537)
at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5097)
at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5092)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Nov 24, 2012 4:47:54 PM org.apache.catalina.core.StandardContext listenerStart
 SEVERE: Error configuring application listener of class    com.olec.listener.HibernateListener
java.lang.ClassNotFoundException: com.olec.listener.HibernateListener
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:415)
at   org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:397)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:118)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4537)
at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5097)
at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5092)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
  Nov 24, 2012 4:47:54 PM org.apache.catalina.core.StandardContext listenerStart
 SEVERE: Skipped installing application listeners due to previous error(s)
  Nov 24, 2012 4:47:54 PM org.apache.catalina.core.StandardContext startInternal
   SEVERE: Error listenerStart
Nov 24, 2012 4:47:54 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Context [/OLEC] startup failed due to previous errors
Nov 24, 2012 4:47:54 PM org.apache.catalina.loader.WebappClassLoader    clearReferencesJdbc
    SEVERE: The web application [/OLEC] registered the JDBC driver                                                                                                                                                 [com.mysql.jdbc.Driver]    but failed to unregister it when the web application   was             stopped. To prevent a                                                          memory leak, the JDBC Driver has been  unregistered.
Nov 24, 2012 4:47:54 PM org.apache.coyote.AbstractProtocolHandler start
: Starting ProtocolHandler ["http-bio-8080"]
Nov 24, 2012 4:47:54 PM org.apache.coyote.AbstractProtocolHandler start
INFO: Starting ProtocolHandler ["ajp-bio-8009"]
Nov 24, 2012 4:47:54 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 2014 ms

Answer 1

您正在使用什么IDE？ 如果是Eclipse或Netbeans，請轉到項目屬性，然后將缺少的jar添加到類路徑中。

根據您的例外情況，您應該添加struts2-tiles-plugin-2.0.12.jar或該jar的任何其他版本。

還要hibernate-annotations.jar，更好地檢查類路徑是否正確。

Answer 2

com.olec.listener.HibernateListener丟失。 我沒有找到包含該類的jar，但是您應該將其添加到您的應用程序或其類路徑中。