HTTP Status 500 – Internal Server ErrorType Exception ReportMessage Error instantiating servlet class [com.demo.servletprg.MyServlet]Description The server encountered an unexpected condition that prevented it from fulfilling the request.Exceptionjakarta.servlet.ServletException: Error instantiating servlet class [com.demo.servletprg.MyServlet] org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) 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:356) org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:870) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1762) org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) java.base/java.lang.Thread.run(Thread.java:1583)Root Causejava.lang.ClassNotFoundException: com.demo.servletprg.MyServlet org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1449) org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1257) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) 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:356) org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:870) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1762) org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) java.base/java.lang.Thread.run(Thread.java:1583)Note The full stack trace of the root cause is available in the server logs.index.html<!DOCTYPE html><html><head><meta charset="UTF-8"><title>sample sevlet</title></head><body><h1 style="color:red">welcome to my page</h1><a href="/Servletprograms/MyServlet"> click here to view MyServlet </a></body></html>myservlet.codepackage com.demo.servletprg;import jakarta.servlet.ServletException;import jakarta.servlet.annotation.WebServlet;import jakarta.servlet.http.HttpServlet;import jakarta.servlet.http.HttpServletRequest;import jakarta.servlet.http.HttpServletResponse;import java.io.IOException;import java.io.PrintWriter;/** * Servlet implementation class MyServlet */public class MyServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public MyServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.getWriter().append("Served at: ").append(request.getContextPath()); PrintWriter out=response.getWriter(); response.setContentType("text/html"); out.println("<br><h1 style=color:green>"+"Welcome To My Servlet"+"</h1>"); }}Apache Tomcat/10.0.27enter image description here
- I'm encountering an issue with my Java web application deployed on Apache Tomcat. When I try to access a servlet, I'm getting an "HTTP Status 500 – Internal Server Error" with the message "Error instantiating servlet class [com.demo.servletprg.MyServlet]". The root cause of this error is a "java.lang.ClassNotFoundException" `for the servlet class.