类com.fqyd.servlet.HelloServlet不是ServletHTTP状态 500 - 内部服务器错误

类com.fqyd.servlet.HelloServlet不是ServletHTTP状态 500 - 内部服务器错误类型异常报告消息类com.fqyd.servlet.HelloServlet不是Servlet描述服务器遇到一个意外的情况，阻止它完成请求。例外情况jakarta.servlet.ServletException: 类com.fqyd.servlet.HelloServlet

skfqyd

796人浏览 · 2021-04-12 22:04:19

skfqyd · 2021-04-12 22:04:19 发布

类com.fqyd.servlet.HelloServlet不是ServletHTTP状态 500 - 内部服务器错误

类型异常报告

消息类com.fqyd.servlet.HelloServlet不是Servlet

描述服务器遇到一个意外的情况，阻止它完成请求。

例外情况

jakarta.servlet.ServletException: 类com.fqyd.servlet.HelloServlet不是Servlet
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:543)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol $C o n n e c t i o n H a n d l e r . p r o c e s s (A b s t r a c t P r o t o c o l . j a v a : 864) o r g . a p a c h e . t o m c a t . u t i l . n e t . N i o E n d p o i n t$ SocketProcessor.doRun(NioEndpoint.java:1655)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
java.util.concurrent.ThreadPoolExecutor $W o r k e r . r u n (T h r e a d P o o l E x e c u t o r . j a v a : 617) o r g . a p a c h e . t o m c a t . u t i l . t h r e a d s . T a s k T h r e a d$ WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Thread.java:745)
根本原因。

java.lang.ClassCastException: com.fqyd.servlet.HelloServlet cannot be cast to jakarta.servlet.Servlet
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:543)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol $C o n n e c t i o n H a n d l e r . p r o c e s s (A b s t r a c t P r o t o c o l . j a v a : 864) o r g . a p a c h e . t o m c a t . u t i l . n e t . N i o E n d p o i n t$ SocketProcessor.doRun(NioEndpoint.java:1655)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
java.util.concurrent.ThreadPoolExecutor $W o r k e r . r u n (T h r e a d P o o l E x e c u t o r . j a v a : 617) o r g . a p a c h e . t o m c a t . u t i l . t h r e a d s . T a s k T h r e a d$ WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Thread.java:745)

在这里插入图片描述 tomcat10之后包名不再"javax.servlet”,改为"jakarta.servlet"
因此将Tomcat版本改为9即可
或者
“javax.servlet”改为"jakarta.servlet”

	<dependency>
      <groupId>jakarta.servlet.jsp</groupId>
      <artifactId>jakarta.servlet.jsp-api</artifactId>
      <version>3.0.0</version>
    </dependency>
    <dependency>
      <groupId>jakarta.servlet</groupId>
      <artifactId>jakarta.servlet-api</artifactId>
      <version>5.0.0</version>
    </dependency>
    <!--类中的导入部分也需要更改
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
-->