All about Bj Krishna

Servlet giving runtimeexception in Netbeans IDE 12 and Apache tomcat 9.0.41 in MacOS

I deleted all projects and installed Netbeans 12 again and created a fresh web application:

Here is the code generated by NETbeans IDE, I didnt change anything but just ran below is the code:

/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package com.bobin;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
*
* @author bobinkrishna
*/
public class SampleServ extends HttpServlet {
   /**
    * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
    * methods.
    *
    * @param request servlet request
    * @param response servlet response
    * @throws ServletException if a servlet-specific error occurs
    * @throws IOException if an I/O error occurs
    */
   protected void processRequest(HttpServletRequest request, HttpServletResponse response)
           throws ServletException, IOException {
       response.setContentType("text/html;charset=UTF-8");
       try ( PrintWriter out = response.getWriter()) {
           /* TODO output your page here. You may use following sample code. */
           out.println("<!DOCTYPE html>");
           out.println("<html>");
           out.println("<head>");
           out.println("<title>Servlet SampleServ</title>");            
           out.println("</head>");
           out.println("<body>");
           out.println("<h1>Servlet SampleServ at " + request.getContextPath() + "</h1>");
           out.println("</body>");
           out.println("</html>");
       }
   }
   // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
   /**
    * Handles the HTTP <code>GET</code> method.
    *
    * @param request servlet request
    * @param response servlet response
    * @throws ServletException if a servlet-specific error occurs
    * @throws IOException if an I/O error occurs
    */
   @Override
   protected void doGet(HttpServletRequest request, HttpServletResponse response)
           throws ServletException, IOException {
       processRequest(request, response);
   }
   /**
    * Handles the HTTP <code>POST</code> method.
    *
    * @param request servlet request
    * @param response servlet response
    * @throws ServletException if a servlet-specific error occurs
    * @throws IOException if an I/O error occurs
    */
   @Override
   protected void doPost(HttpServletRequest request, HttpServletResponse response)
           throws ServletException, IOException {
       processRequest(request, response);
   }
   /**
    * Returns a short description of the servlet.
    *
    * @return a String containing servlet description
    */
   @Override
   public String getServletInfo() {
       return "Short description";
   }// </editor-fold>
}

web.xml file:

error from browser:

HTTP Status 500 – Internal Server Error

Type Exception Report

Message Error instantiating servlet class [com.bobin.SampleServ]

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

javax.servlet.ServletException: Error instantiating servlet class [com.bobin.SampleServ]
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:343)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:888)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1597)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.base/java.lang.Thread.run(Thread.java:832)
Root Cause

java.lang.RuntimeException:
com.bobin.SampleServ.<init>(SampleServ.java:1)
java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:64)
java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481)
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:343)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:888)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1597)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.base/java.lang.Thread.run(Thread.java:832)

log file:

13-Jan-2021 16:24:03.961 INFO [http-nio-8081-exec-12] org.apache.catalina.core.ApplicationContext.log Marking servlet [SampleServ] as unavailable
13-Jan-2021 16:24:03.961 SEVERE [http-nio-8081-exec-12] org.apache.catalina.core.StandardWrapperValve.invoke Allocate exception for servlet [SampleServ]
java.lang.RuntimeException:
at com.bobin.SampleServ.<init>(SampleServ.java:1)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:64)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:151)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1042)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:761)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:135)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:888)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1597)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.base/java.lang.Thread.run(Thread.java:832)

1 week ago

Servlets

Servlet giving runtimeexception in Netbeans IDE 12 and Apache tomcat 9.0.41 in MacOS

error response from browser:

1 week ago

Servlets

Servlet giving runtimeexception in Netbeans IDE 12 and Apache tomcat 9.0.41 in MacOS

HTTPServlet:

1 week ago

Servlets

Servlet giving runtimeexception in Netbeans IDE 12 and Apache tomcat 9.0.41 in MacOS

snapshot of httpservlet:

1 week ago

Servlets

Servlet giving runtimeexception in Netbeans IDE 12 and Apache tomcat 9.0.41 in MacOS

Tim as you requested I created a HTTPServlet and attached the entire code and response from the browser.

1 week ago

Servlets

Servlet giving runtimeexception in Netbeans IDE 12 and Apache tomcat 9.0.41 in MacOS

Given you the snapshot of the code in IDE in the attached image. Also as you can see a small rounded i in front of the service method line which shows that I am just implementing the service method and I am sure this as worked before in the same netbeans. Also have a doubt when my web applications loads it shows up the index.html page and then I include the URL-pattern in the URL to run the application, could this be a problem should I need to link it from the index.html. Thank you.

let me know if anything else needed.

Thanks,
Krishna

1 week ago

Servlets

Servlet giving runtimeexception in Netbeans IDE 12 and Apache tomcat 9.0.41 in MacOS

Hi Tim: this is the catalina logs: I doubted why it shows this warning and whether this could be a reason but couldnt figure it out. I have copied the ones that matches with the time stamp of stack trace.

12-Jan-2021 21:53:02.463 INFO [http-nio-8081-exec-15] org.apache.catalina.startup.HostConfig.undeploy Undeploying context [/webapp1]
12-Jan-2021 21:53:07.567 INFO [http-nio-8081-exec-16] org.apache.catalina.startup.HostConfig.deployDescriptor Deploying deployment descriptor [/Users/bobinkrishna/Java/apache-tomcat-9.0.41/conf/Catalina/localhost/webapp1.xml]
12-Jan-2021 21:53:07.567 WARNING [http-nio-8081-exec-16] org.apache.catalina.startup.HostConfig.deployDescriptor The path attribute with value [/webapp1] in deployment descriptor [/Users/bobinkrishna/Java/apache-tomcat-9.0.41/conf/Catalina/localhost/webapp1.xml] has been ignored
12-Jan-2021 21:53:07.591 INFO [http-nio-8081-exec-16] org.apache.catalina.startup.HostConfig.deployDescriptor Deployment of deployment descriptor [/Users/bobinkrishna/Java/apache-tomcat-9.0.41/conf/Catalina/localhost/webapp1.xml] has finished in [25] ms
12-Jan-2021 21:53:07.596 INFO [http-nio-8081-exec-19] org.apache.catalina.util.LifecycleBase.start The start() method was called on component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/webapp1]] after start() had already been called. The second call will be ignored.
12-Jan-2021 21:53:41.814 INFO [http-nio-8081-exec-19] org.apache.catalina.core.StandardContext.reload Reloading Context with name [/webapp1] has started
12-Jan-2021 21:53:41.836 INFO [http-nio-8081-exec-19] org.apache.catalina.core.StandardContext.reload Reloading Context with name [/webapp1] is completed
12-Jan-2021 21:53:51.229 INFO [http-nio-8081-exec-13] org.apache.catalina.core.StandardContext.reload Reloading Context with name [/webapp1] has started
12-Jan-2021 21:53:51.250 INFO [http-nio-8081-exec-13] org.apache.catalina.core.StandardContext.reload Reloading Context with name [/webapp1] is completed
12-Jan-2021 21:54:11.322 INFO [http-nio-8081-exec-19] org.apache.catalina.core.StandardContext.reload Reloading Context with name [/webapp1] has started
12-Jan-2021 21:54:11.336 INFO [http-nio-8081-exec-19] org.apache.catalina.core.StandardContext.reload Reloading Context with name [/webapp1] is completed
12-Jan-2021 21:54:25.636 INFO [http-nio-8081-exec-16] org.apache.catalina.startup.HostConfig.undeploy Undeploying context [/webapp1]
12-Jan-2021 21:54:29.897 INFO [http-nio-8081-exec-11] org.apache.catalina.startup.HostConfig.deployDescriptor Deploying deployment descriptor [/Users/bobinkrishna/Java/apache-tomcat-9.0.41/conf/Catalina/localhost/webapp1.xml]
12-Jan-2021 21:54:29.898 WARNING [http-nio-8081-exec-11] org.apache.catalina.startup.HostConfig.deployDescriptor The path attribute with value [/webapp1] in deployment descriptor [/Users/bobinkrishna/Java/apache-tomcat-9.0.41/conf/Catalina/localhost/webapp1.xml] has been ignored
12-Jan-2021 21:54:29.929 INFO [http-nio-8081-exec-11] org.apache.catalina.startup.HostConfig.deployDescriptor Deployment of deployment descriptor [/Users/bobinkrishna/Java/apache-tomcat-9.0.41/conf/Catalina/localhost/webapp1.xml] has finished in [32] ms
12-Jan-2021 21:54:29.938 INFO [http-nio-8081-exec-25] org.apache.catalina.util.LifecycleBase.start The start() method was called on component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/webapp1]] after start() had already been called. The second call will be ignored.

It is my own example Tim which worked separately when I run it out of IDE. The IDE creates a HTTPServlet by default but it was giving this error, so what I did was I removed the HTTPservlet and used GenericServlet just to check if it works without any error but it still gives the same error. I basically deleted the collapsed methods of HTTPServlet which is what Dave is asking for but that is not in the code any more. what I copied is what exists in Servlet.

Did I give you the information you are looking out for ? also as you mentioned where can I check for any member variable defined whose initialization expression failed? thank you for your help.

1 week ago

Servlets

Servlet giving runtimeexception in Netbeans IDE 12 and Apache tomcat 9.0.41 in MacOS

a simple servlet:

web.xml:

but I get the following error:

12-Jan-2021 21:53:14.428 INFO [http-nio-8081-exec-11] org.apache.catalina.core.ApplicationContext.log Marking servlet [firstServlet] as unavailable
12-Jan-2021 21:53:14.428 SEVERE [http-nio-8081-exec-11] org.apache.catalina.core.StandardWrapperValve.invoke Allocate exception for servlet [firstServlet]
java.lang.RuntimeException:
at simple.servlets.FirstServlet.<init>(FirstServlet.java:1)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:64)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:151)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1042)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:761)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:135)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:888)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1597)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.base/java.lang.Thread.run(Thread.java:832)
12-Jan-2021 21:54:33.982 INFO [http-nio-8081-exec-26] org.apache.catalina.core.ApplicationContext.log Marking servlet [firstServlet] as unavailable
12-Jan-2021 21:54:33.983 SEVERE [http-nio-8081-exec-26] org.apache.catalina.core.StandardWrapperValve.invoke Allocate exception for servlet [firstServlet]
java.lang.RuntimeException:
at simple.servlets.FirstServlet.<init>(FirstServlet.java:1)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:64)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:151)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1042)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:761)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:135)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:888)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1597)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.base/java.lang.Thread.run(Thread.java:832)

servlet-api.jar is correctly mapped to CLASSPATH. Any help to resolve it would be appreciated.

1 week ago

Servlets

Bj Krishna

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