javax.servlet.ServletException: Error instantiating servlet class servlet.DeleteData

Question

I have this servlet DeleteData.java

package sevenet;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.*;
import java.sql.*;

@WebServlet("/deleteData")
public class DeleteData extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // Some code.
    }
}

Which is registered as below in web.xml

<servlet>
    <servlet-name>DeleteData</servlet-name>
    <servlet-class>servlet.DeleteData</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>DeleteData</servlet-name>
    <url-pattern>/DeleteData</url-pattern>
</servlet-mapping>

I got error when starting the webapp:

javax.servlet.ServletException: Error instantiating servlet class servlet.DeleteData
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672)
    org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2500)
    org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2489)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Thread.java:745)

How is this caused and how can I solve it?

use servlet for getting id and using send redirect or request dispatcher ,send control to main servlet (or) use html page take input using form action and send control to main servlet — khaja firoz, Mar 25 '16 at 12:21
Regarding the error message -- Try to remove the servlet/servlet mapping entries from your web.xml because they're redundant (since you're already using annotations) — dsp_user, Mar 25 '16 at 13:51
Warning: you're mixing 2 different ways of registering servlets. Make sure you read correct and up to date resources when learning servlets. A good starting point is our servlets wiki page. Hover the [servlets] tag below the question until a black popbox shows up and then click therein *info* link. — BalusC, Mar 25 '16 at 15:47

score 1 · Accepted Answer · answered Mar 25 '16 at 14:58

There is typo in package name package sevenet; in DeleteData.java

Either correct package name in DeleteData.java or update the package name in web.xml like this:

<servlet>
    <servlet-name>DeleteData</servlet-name>
    <servlet-class>sevenet.DeleteData</servlet-class>
</servlet>

score 0 · Answer 2 · answered Mar 25 '16 at 16:37

0

You have forgotten the @Override annotation on doGet() and the DeleteData servlet package name is incorrect in the web.xml

answered Mar 25 '16 at 16:37

The Bitman

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javax.servlet.ServletException: Error instantiating servlet class servlet.DeleteData

2 Answers2