升级到 WAS 7 后的 javax.servlet.UnavailableException

Question

我已将我的应用程序从 WAS 6 迁移到 WAS 7。代码没有显示任何编译错误或遗漏任何内容，但是当我尝试运行该应用程序时，出现以下异常。

 [9/19/12 9:45:37:609 EDT] 00000009 extension     W com.ibm.wsspi.webcontainer.extension.WebExtensionProcessor createServletWrapper Servlet action is currently unavailable: SRVE0203E: Servlet [action]: com.ibm.services.tools.citrus.ctl.ActionServlet was found, but is missing another required class.
    SRVE0206E: This error typically implies that the servlet was originally compiled with classes which cannot be located by the server.

所以我检查了 ffdc 异常跟踪，发现了以下异常。我已经包含了旧配置引用的所有 jar。

    [9/19/12 9:26:53:328 EDT]     FFDC Exception:javax.servlet.UnavailableException SourceId:com.ibm.ws.webcontainer.webapp.WebApp.handleError ProbeId:912 Reporter:com.ibm.ws.webcontainer.webapp.WebAppImpl@475c475c
javax.servlet.UnavailableException: SRVE0203E: Servlet [action]: com.ibm.services.tools.citrus.ctl.ActionServlet was found, but is missing another required class.
SRVE0206E: This error typically implies that the servlet was originally compiled with classes which cannot be located by the server.
SRVE0187E: Check your class path to ensure that all classes required by the servlet are present.SRVE0210I: This problem can be debugged by recompiling the servlet using only the classes in the application's runtime class path
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:534)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:502)
    at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:179)
    at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.forward(WebAppRequestDispatcher.java:354)
    at com.ibm.ws.webcontainer.webapp.WebApp.sendError(WebApp.java:3369)
    at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:3968)
    at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:276)
    at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:931)
    at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1583)
    at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:186)
    at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:452)
    at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:511)
    at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:305)
    at com.ibm.ws.http.channel.inbound.impl.HttpICLReadCallback.complete(HttpICLReadCallback.java:83)
    at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:165)
    at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)
    at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)
    at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138)
    at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204)
    at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775)
    at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905)
    at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1604)

我想了解可以通过仅使用应用程序运行时类路径中的类重新编译 servlet 来调试此问题的含义。

Answer 1

该错误表明您的 servlet 正在导入或依赖于升级后不再可用的类。由于异常没有命名缺少的类，WAS 建议您针对 WAS 7 库编译您的应用程序。如果你这样做，编译器会告诉你缺少哪个依赖类。您可能正在针对 WAS 6 或其他一些库进行编译，这就是错误延迟到运行时的原因。