springboot访问jsp页面报错

Question

springboot访问jsp页面一直报如下错误java.lang.ClassNotFoundException: javax.servlet.Servlet
at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_77]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_77]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_77]
at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.8.0_77]
at java.lang.ClassLoader.defineClass(ClassLoader.java:763) ~[na:1.8.0_77]
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[na:1.8.0_77]
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) ~[na:1.8.0_77]
at java.net.URLClassLoader.access$100(URLClassLoader.java:73) ~[na:1.8.0_77]
at java.net.URLClassLoader$1.run(URLClassLoader.java:368) ~[na:1.8.0_77]
at java.net.URLClassLoader$1.run(URLClassLoader.java:362) ~[na:1.8.0_77]
at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_77]
at java.net.URLClassLoader.findClass(URLClassLoader.java:361) ~[na:1.8.0_77]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_77]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_77]
at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.8.0_77]
at java.lang.ClassLoader.defineClass(ClassLoader.java:763) ~[na:1.8.0_77]
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[na:1.8.0_77]
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) ~[na:1.8.0_77]
at java.net.URLClassLoader.access$100(URLClassLoader.java:73) ~[na:1.8.0_77]
at java.net.URLClassLoader$1.run(URLClassLoader.java:368) ~[na:1.8.0_77]
at java.net.URLClassLoader$1.run(URLClassLoader.java:362) ~[na:1.8.0_77]
at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_77]
at java.net.URLClassLoader.findClass(URLClassLoader.java:361) ~[na:1.8.0_77]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_77]
at java.lang.ClassLoader.loadClass(ClassLoader.java:411) ~[na:1.8.0_77]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_77]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_77]
at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.8.0_77]
at java.lang.ClassLoader.defineClass(ClassLoader.java:763) ~[na:1.8.0_77]
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[na:1.8.0_77]
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) ~[na:1.8.0_77]
at java.net.URLClassLoader.access$100(URLClassLoader.java:73) ~[na:1.8.0_77]
at java.net.URLClassLoader$1.run(URLClassLoader.java:368) ~[na:1.8.0_77]
at java.net.URLClassLoader$1.run(URLClassLoader.java:362) ~[na:1.8.0_77]
at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_77]
at java.net.URLClassLoader.findClass(URLClassLoader.java:361) ~[na:1.8.0_77]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_77]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_77]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_77]
at org.springframework.boot.devtools.restart.classloader.RestartClassLoader.loadClass(RestartClassLoader.java:148) ~[spring-boot-devtools-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_77]
at java.lang.Class.forName0(Native Method) ~[na:1.8.0_77]
at java.lang.Class.forName(Class.java:348) ~[na:1.8.0_77]
at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.loadFromParent(TomcatEmbeddedWebappClassLoader.java:112) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.doLoadClass(TomcatEmbeddedWebappClassLoader.java:85) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.loadClass(TomcatEmbeddedWebappClassLoader.java:68) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1137) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:123) ~[tomcat-embed-jasper-8.5.34.jar:8.5.34]
at org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:60) ~[tomcat-embed-jasper-8.5.34.jar:8.5.34]
at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.8.0_77]
at java.lang.ClassLoader.defineClass(ClassLoader.java:763) ~[na:1.8.0_77]
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[na:1.8.0_77]
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) ~[na:1.8.0_77]
at java.net.URLClassLoader.access$100(URLClassLoader.java:73) ~[na:1.8.0_77]
at java.net.URLClassLoader$1.run(URLClassLoader.java:368) ~[na:1.8.0_77]
at java.net.URLClassLoader$1.run(URLClassLoader.java:362) ~[na:1.8.0_77]
at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_77]
at java.net.URLClassLoader.findClass(URLClassLoader.java:361) ~[na:1.8.0_77]
at org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:129) ~[tomcat-embed-jasper-8.5.34.jar:8.5.34]
at org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:60) ~[tomcat-embed-jasper-8.5.34.jar:8.5.34]
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:159) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:185) ~[tomcat-embed-jasper-8.5.34.jar:8.5.34]
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:394) ~[tomcat-embed-jasper-8.5.34.jar:8.5.34]
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386) ~[tomcat-embed-jasper-8.5.34.jar:8.5.34]
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330) ~[tomcat-embed-jasper-8.5.34.jar:8.5.34]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:728) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:470) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:395) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:316) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:170) ~[spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:315) ~[spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1325) ~[spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1069) ~[spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1008) ~[spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866) ~[spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:806) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.34.jar:8.5.34]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_77]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_77]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.34.jar:8.5.34]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_77]

Answer 1

是不是少了servlet-api.jar包，在pom.xml中加入依赖看下

  <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>servlet-api</artifactId>
      <version>2.5</version>
    </dependency>