javax.servlet.UnavailableException : No class in holder on deployed application with jsp

Question

我在实现以下目标时遇到了一些问题:

我希望我的后端在一些定义的路径上返回我的 index.html 页面，因为它是一个角度应用程序。

在我的 web.xml 中我写了:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">

  <!--my servlets-->

  <!--HTML5-->
    <servlet>
        <servlet-name>html5Servlet</servlet-name>
        <jsp-file>/index.html</jsp-file>
    </servlet>
    <servlet-mapping>
        <servlet-name>html5Servlet</servlet-name>
        <url-pattern>/</url-pattern>
        <url-pattern>/home</url-pattern>
        <url-pattern>/wp-users</url-pattern>
        <url-pattern>/wp-groups</url-pattern>
    </servlet-mapping>
    <!--HTML5-->

    <security-constraint>
        <web-resource-collection>
            <web-resource-name>all</web-resource-name>
            <url-pattern>/*</url-pattern>
        </web-resource-collection>
        <user-data-constraint>
            <transport-guarantee>CONFIDENTIAL</transport-guarantee>
        </user-data-constraint>
    </security-constraint>

</web-app>

该应用程序在本地运行良好，但是我在调​​用我的 servlet 时在已部署的应用程序上收到以下错误:

javax.servlet.ServletContext log: unavailable
javax.servlet.UnavailableException: No class in holder html5Servlet@830ae0fb==null,jsp=/index.html,order=-1,inst=false
    at org.eclipse.jetty.servlet.BaseHolder.doStart(BaseHolder.java:88)
    at org.eclipse.jetty.servlet.ServletHolder.doStart(ServletHolder.java:363)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:891)
    at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:349)
    at org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1406)
    at com.google.apphosting.runtime.jetty9.AppEngineWebAppContext.startWebapp(AppEngineWebAppContext.java:159)
    at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1368)
    at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:778)
    at org.eclipse.jetty.servlet.ServletContextHandler.doStart(ServletContextHandler.java:262)
    at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:522)
    at com.google.apphosting.runtime.jetty9.AppEngineWebAppContext.doStart(AppEngineWebAppContext.java:116)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at com.google.apphosting.runtime.jetty9.AppVersionHandlerMap.createHandler(AppVersionHandlerMap.java:244)
    at com.google.apphosting.runtime.jetty9.AppVersionHandlerMap.getHandler(AppVersionHandlerMap.java:182)
    at com.google.apphosting.runtime.jetty9.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:109)
    at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.dispatchServletRequest(JavaRuntime.java:693)
    at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.dispatchRequest(JavaRuntime.java:655)
    at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:625)
    at com.google.apphosting.runtime.JavaRuntime$NullSandboxRequestRunnable.run(JavaRuntime.java:819)
    at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:274)
    at java.lang.Thread.run(Thread.java:745)

缺课的时候没看懂。我也尝试过使用 jsp 文件而不是 html 文件，但它不起作用。有人有任何线索吗？

Answer 1

*.html不是公认的 servlet <url-pattern>用于 JSP。

切换到index.jsp和 JettyJspServlet应该开始将其识别为 JSP 文件。