Error allocating a servlet instance应该怎么解决？

gaofuqi 2010-01-08 08:03:40

以下是异常信息：



type Exception report



message 



description The server encountered an internal error () that prevented it from fulfilling this request.



exception 



javax.servlet.ServletException: Error allocating a servlet instance

	org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)

	org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)

	org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)

	org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)

	org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)

	org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)

	org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)

	java.lang.Thread.run(Unknown Source)





root cause 



java.lang.UnsupportedClassVersionError: Bad version number in .class file

	java.lang.ClassLoader.defineClass1(Native Method)

	java.lang.ClassLoader.defineClass(Unknown Source)

	java.security.SecureClassLoader.defineClass(Unknown Source)

	org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1853)

	org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:875)

	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1330)

	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1209)

	org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)

	org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)

	org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)

	org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)

	org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)

	org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)

	org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)

	java.lang.Thread.run(Unknown Source)





note The full stack trace of the root cause is available in the Apache Tomcat/5.5.26 logs.

以下是web.xml的内容：





   <servlet>

<servlet-name>DisplayChart</servlet-name>

<servlet-class>org.jfree.chart.servlet.DisplayChart</servlet-class>

</servlet>

  <servlet>

    <description>This is the description of my J2EE component</description>

    <display-name>This is the display name of my J2EE component</display-name>

    <servlet-name>JFreechartServlet</servlet-name>

    <servlet-class>com.juanyuan.jfreechart.control.JFreechartServlet</servlet-class>

  </servlet>



<servlet-mapping>

<servlet-name>DisplayChart</servlet-name>

<url-pattern>/DisplayChart</url-pattern>

</servlet-mapping>

  <servlet-mapping>

    <servlet-name>JFreechartServlet</servlet-name>

    <url-pattern>/JFreechartServlet</url-pattern>

  </servlet-mapping>



  <welcome-file-list>

    <welcome-file>index.jsp</welcome-file>

  </welcome-file-list>

</web-app>