I am trying to create an HTML form which displays text from a text file, using a Java Servlet. I keep getting the following error: Error instantiating servlet class servlets.ReportServlet.

Here is the HTML page:

    <title>TODO supply a title</title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <form name = "managementReports" method = "get" action = 
    <input type="submit">

And here is my servlet:

package servlets;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import javax.servlet.annotation.WebServlet;
@WebServlet(urlPatterns = { "/ReportServlet" })
public class ReportServlet extends HttpServlet   
public void service(HttpServletRequest req, HttpServletResponse res) throws 
ServletException, IOException  
PrintWriter pw = res.getWriter();
String name = req.getParameter("filename");
BufferedReader br = new BufferedReader(new 
String str;
while( (str = br.readLine()) != null )
 pw.println(str + "<BR>");

Here is my web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"

I have been searching google for days but I am still struggling with this

Recommended Answers

Just so others know, there are replies at https://www.daniweb.com/community-center/threads/509357/how-to-read-from-a-text-file-into-an-html-page-using-java-servlet

So this must be so the post is in the right forum but I fear you are ignoring prior discussions on the subject.

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@R I hear you clearly but to work this you either use priors or if you want to start from scratch, break the goal into manageable chunks.

In the 62 lines above, install what some call debug statements so you can see where your code breaks down.

Added with edit.

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I have marked that question as resolved and put it onto the right forum. I followed the link you sent me but I am still getting nowhere with it.

@R I hear you clearly but to work this you either use priors or if you want to start from scratch, break the goal into manageable chunks.

In the 62 lines above, install what some call debug statements so you can see where your code breaks down.

Added with edit.

Just a thought, did not test it out. I worry about reading files in Java. I've lost count of how many times the file path is incorrect or permissions didn't allow the file to be read.

@rproffitt I had a go at that and this is what comes up:

java.lang.ClassNotFoundException: servlets.ReportServlet
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1285)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:520)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:501)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:118)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1050)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:779)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:133)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:789)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

There are tutorials about that error such as https://dzone.com/articles/how-resolve-2

Sorry if I can't solve this for you as I don't have your server to replicate the issue. It does sound as if it's well discussed over the years.

I will keep researching, thanks anyway

I am feeling a lot of deja vu here...

You should not use both annotation based and xml based web application configuration in the same web application.
Choose one or the other and stick with it.

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