Ошибка 404 при запуске tomcat

In Java web development with Tomcat, it’s very often that you get HTTP 404 error like this:

The error code is HTTP 404 (not found) and the description is:

The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.

This error means the server could not find the requested resource (JSP, HTML, images…) and returns HTTP status code 404. Most of the time, you can fix this error by correcting the URL. However, sometimes it’s not easy like that, making it is an annoying error.

Here I suggest some possible reasons and how to fix the error HTTP 404 in Java web development with Tomcat.

1. The URL is not handled by any Java servlets

You need to check URL mapping in your servlet classes to make sure the requested URL is actually handled by a servlet. For example:

@WebServlet("/view_book")
public class ViewBookServlet extends HttpServlet {
...
}

This servlet handles the URL /view_book. If the request URL is /view_books the server will raise HTTP 404 error. You can fix by either correcting the URL or correcting the URL mapping in the @WebServlet annotation.

In older Java web application, you have to check the web deployment descriptor file web.xml because a Java servlet can be mapped to URL via XML like this:

<servlet-mapping>
    <servlet-name>ViewBookServlet</servlet-name>
    <url-pattern>/view_book</url-pattern>
</servlet-mapping>

2. Java servlet forwarding to a resource that does not exist

In this case, the requested URL is handled by a Java servlet, but code in the servlet forwards to a resource (JSP, HTML…) which does not exist, as shown in the following screenshot:

The code in the servlet class would look like this:

String registerForm = "frontend/registerform.jsp";
RequestDispatcher dispatcher = request.getRequestDispatcher(registerForm);
dispatcher.forward(request, response);

You can fix by correcting the forward path in the servlet, and make sure that the forwarded resource does actually exist in the given path.

3. URL is case-sensitive

Note that Tomcat treats URL as case-sensitive, for instance /Register is different than /register. So you need to check and use correct case for the letters in request URL.

Also pay attention to the webapp name in the URL, for instance http://localhost:8080/BookstoreWebsite/ is different than http://localhost:8080/BookStoreWebsite/

TIP: in Eclipse, you can right click on the project, then click Run As > Run on Server, the IDE will always use the correct name of the web application.

Finally, you should not let the user see the raw HTTP 404 error page rendered by the server. Instead, you should design your own user-friendly 404 error page – follow this tutorial: How to Handle Error for Java web applications.

You can also watch the video version below:

Other Java Servlet Tutorials:

• Java Servlet Quick Start for beginners (XML)
• Java Servlet for beginners (annotations)
• Java Servlet and JSP Hello World Tutorial with Eclipse, Maven and Apache Tomcat
• Handling HTML form data with Java Servlet
• Java File Download Servlet Example

Related Article — Java Error

Class Has Been Compiled by a More Recent Version of Java Runtime

[Solved] Tomcat Error HTTP Status 404 Not Found

The error code is HTTP 404 (not found) and the description is:

The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.

This error means the server could not find the requested resource (JSP, HTML, images…) and returns HTTP status code 404. Most of the time, you can fix this error by correcting the URL. However, sometimes it’s not easy like that, making it is an annoying error.

Here I suggest some possible reasons and how to fix the error HTTP 404 in Java web development with Tomcat.

1. The URL is not handled by any Java servlets

You need to check URL mapping in your servlet classes to make sure the requested URL is actually handled by a servlet. For example:

This servlet handles the URL /view_book . If the request URL is /view_books the server will raise HTTP 404 error. You can fix by either correcting the URL or correcting the URL mapping in the @WebServlet annotation.

2. Java servlet forwarding to a resource that does not exist

In this case, the requested URL is handled by a Java servlet, but code in the servlet forwards to a resource (JSP, HTML…) which does not exist, as shown in the following screenshot:

The code in the servlet class would look like this:

You can fix by correcting the forward path in the servlet, and make sure that the forwarded resource does actually exist in the given path.

3. URL is case-sensitive

Note that Tomcat treats URL as case-sensitive, for instance /Register is different than /register . So you need to check and use correct case for the letters in request URL.

Also pay attention to the webapp name in the URL, for instance http://localhost:8080/BookstoreWebsite/ is different than http://localhost:8080/BookStoreWebsite/

TIP: in Eclipse, you can right click on the project, then click Run As > Run on Server, the IDE will always use the correct name of the web application.

Finally, you should not let the user see the raw HTTP 404 error page rendered by the server. Instead, you should design your own user-friendly 404 error page – follow this tutorial: How to Handle Error for Java web applications.

You can also watch the video version below:

Other Java Servlet Tutorials:

Nam Ha Minh is certified Java programmer (SCJP and SCWCD). He started programming with Java in the time of Java 1.4 and has been falling in love with Java since then. Make friend with him on Facebook and watch his Java videos you YouTube.

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Tomcat 404 Error

This tutorial demonstrates how to troubleshoot the Tomcat 404 error in Java.

Tomcat 404 Error in Java

While using the apache Tomcat server for web development in Java, the most common error is the HTTP Status 404 . This error means the server cannot find the required resource.

The required file can be anything like HTML, Image Resource or JSP.

Most of the time, the error occurs when the required reference is not present or is referenced incorrectly. The error looks like this:

There are three main reasons for this error in Apache Tomcat.

The URL is Case Sensitive

The Tomcat URLs are case sensitive, so whenever you are trying to write the URL by yourself, make sure that it is also correct in its case. Otherwise, it will throw the 404 status error.

The Servlets Do Not Handle the URL

The @Webservlet() is also used to handle the URL/demo , but when requesting the URL, it can be URL/this_demo , which is a different reference. This can be fixed by using the URL mapping and referencing the URL correctly.

Now, if the website requests the URL this_demo , we can solve it by changing the demo to this_demo in the URL mapping.

Resource Forward by Servlets Does Not Exist

When the resource forwarded by servlets does not exist, the Tomcat will throw a 404 error. Make sure the resource forwarded exists and the name of that resource is correct.

For example, if we are referencing the DemoForm.jsp but the real name of that resource is Demo_Form.jsp , it will throw the 404 status error. We can change the DemoForm.jsp to Demo_Form.jsp to solve this error.

Tomcat 404 Error in Eclipse

While working with Tomcat in Eclipse IDE, the same 404 error can occur even if we have managed all the solutions above. Sometimes, even if the Tomcat starts, the browser will throw the 404 error while working with Eclipse IDE.

This error is because Tomcat is not configured correctly in the Eclipse IDE. To solve this issue in Eclipse, follow the steps below.

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HTTP Status 404 in Tomcat

I just posted a question about compiling a servlet and now I can compile a servlet successfully.

But now I am having problem accessing my «world famous» HelloWorld servlet. My servlet is in webappsexercisesWEB-INFclasses directory.

I am acessing my servlet like this:
http://localhost:8080/exercises/servlet/HelloWorld

but I am ending up with the following error: Can anyone tell me why am I getting this? Thanks!

Have you turned on the invoker servlet?

uncomment the lines in $TOMCATconfweb.xml

this executes anonymous servlet classes that have not been defined in a web.xml file.

alternatively you could start with correct procedures and add your hello world servlet to web.xml

I get the same problem when I try to run my servlet. My servlet is in myappwebbuildWEB-INFclasses directory.

I am acessing my servlet like this:
http://localhost:8080/myapp/servlet/HelloWorld

and I end up with the same error. I checked my web.xml file and the invoker servlet is already commented.

Can anyone tell me what else could be going wrong?

Thanks alot.
Rana

. (after being sure Tomcat is correctly configured [by getting the tomcat HTML page when hitting http://localhost:8080 ] on your browser. only after that).

To solve the problem I had to modify the «conf/server.xml» by adding the code lines that follow just before (or near) the

The lines of the logger generate a .txt file that record information on log details and errors that happened to be on every executable file under «PacoApps» every session Tomcat starts (half guess). The resulting file will be kept in the «%CATALINA_HOME/logs» folder under the name «localhost_PacoApps_log.txt» in my case.

To let Tomcat see your servlet files you also have to uncomment the the following section in the «conf/web.xml» file (it is XML-commented at least in the jakarta-tomcat-4.1.24 version):

invoker /servlet/*
Probably you should restart Tomcat 2 or 3 times just to make shure changes are being considered. With those changes everything runs smoothly. Servlets run by hitting «http://localhost:8080/PacoApps/servlet/ServletName» on your browser, the JavaServer Pages by «http://localhost:8080/PacoApps/MyJSPExample.jsp», html pages by «http://localhost:8080/PacoApps/myPage.htm», etc.

Hope this helps !

EXTRA HINT: Watch out for comment tag nesting within XML files. Don?t put comment tags within comment tags. They can cause you some hard trouble. At least they did to me.

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Servlet returns “HTTP Status 404 The requested resource (/servlet) is not available” [Answered]

Sample problem:

I have an HTML form in a JSP file in my WebContent/jsps folder. I have a servlet class servlet.java in my default package in src folder. In my web.xml it is mapped as /servlet .

I have tried several URLs in action attribute of the HTML form:

But none of those work. They all keep returning a HTTP 404 error like below in Tomcat 6/7/8:

HTTP Status 404 — /servlet

Description: The requested resource (/servlet) is not available.

Or as below in Tomcat 8.5/9:

HTTP Status 404 — Not Found

Description: The origin server did not find a current representation for the target resource or is not willing to disclose that one exists

Why is it not working?

Answer #1:

Introduction

This can have a lot of causes which are broken down in following sections:

• Put servlet class in a package
• Set servlet URL in url-pattern
• @WebServlet works only on Servlet 3.0 or newer
• javax.servlet.* doesn’t work anymore in Servlet 5.0 or newer
• Make sure compiled *.class file is present in built WAR
• Test the servlet individually without any JSP/HTML page
• Use domain-relative URL to reference servlet from HTML
• Use straight quotes in HTML attributes

Put servlet class in a package

First of all, put the servlet class in a Java package . You should always put publicly reuseable Java classes in a package, otherwise they are invisible to classes which are in a package, such as the server itself. This way you eliminate potential environment-specific problems. Packageless servlets work only in specific Tomcat+JDK combinations and this should never be relied upon.

In case of a “plain” IDE project, the class needs to be placed in its package structure inside the “Java Sources” folder, not inside “Web Content” folder, which is for web files such as JSP. Below is an example of the folder structure of a default Eclipse Dynamic Web Project as seen in Navigator view (the “Java Sources” folder is in such project by default represented by src folder):

In case of a Maven project, the class needs to be placed in its package structure inside main/java and thus not main/resources , this is for non-class files and absolutely also not main/webapp , this is for web files. Below is an example of the folder structure of a default Maven webapp project as seen in Eclipse’s Navigator view:

Note that the /jsps subfolder is not strictly necessary. You can even do without it and put the JSP file directly in webcontent/webapp root, but I’m just taking over this from your question.

Set servlet URL in url-pattern

The servlet URL is specified as the “URL pattern” of the servlet mapping. It’s absolutely not per definition the classname/filename of the servlet class. The URL pattern is to be specified as value of @WebServlet annotation.

In case you want to support path parameters like /servlet/foo/bar , then use an URL pattern of /servlet/* instead. See also Servlet and path parameters like /xyz//test, how to map in web.xml?

@WebServlet works only on Servlet 3.0 or newer

In order to use @WebServlet , you only need to make sure that your web.xml file, if any (it’s optional since Servlet 3.0), is declared conform Servlet 3.0+ version and thus not conform e.g. 2.5 version or lower. Below is a Servlet 4.0 compatible one (which matches Tomcat 9+, WildFly 11+, Payara 5+, etc).

Or, in case you’re not on Servlet 3.0+ yet (e.g. Tomcat 6 or older), then remove the @WebServlet annotation.

And register the servlet instead in web.xml like this:

Note thus that you should not use both ways. Use either annotation based configuarion or XML based configuration. When you have both, then XML based configuration will override annotation based configuration.

javax.servlet.* doesn’t work anymore in Servlet 5.0 or newer

Since Jakarta EE 9 / Servlet 5.0 (Tomcat 10, TomEE 9, WildFly 22 Preview, GlassFish 6, Payara 6, Liberty 22, etc), the javax.* package has been renamed to jakarta.* package.

In other words, please make absolutely sure that you don’t randomly put JAR files of a different server in your WAR project such as tomcat-servlet-api-9.x.x.jar merely in order to get the javax.* package to compile. This will only cause trouble. Remove it altogether and edit the imports of your servlet class from

In case you’re using Maven, you can find examples of proper pom.xml declarations for Tomcat 10+, Tomcat 9-, JEE 9+ and JEE 8- in this answer: Tomcat casting servlets to javax.servlet.Servlet instead of jakarta.servlet.http.HttpServlet

Make sure compiled *.class file is present in built WAR

In case you’re using a build tool such as Eclipse and/or Maven, then you need to make absolutely sure that the compiled servlet class file resides in its package structure in /WEB-INF/classes folder of the produced WAR file. In case of package com.example; public class YourServlet , it must be located in /WEB-INF/classes/com/example/YourServlet.class . Otherwise you will face in case of @WebServlet also a 404 error, or in case of a HTTP 500 error like below:

HTTP Status 500

Error instantiating servlet class com.example.YourServlet

And find in the server log a java.lang.ClassNotFoundException: com.example.YourServlet , followed by a java.lang.NoClassDefFoundError: com.example.YourServlet , in turn followed by javax.servlet.ServletException: Error instantiating servlet class com.example.YourServlet .

An easy way to verify if the servlet is correctly compiled and placed in classpath is to let the build tool produce a WAR file (e.g. rightclick project, Export > WAR file in Eclipse) and then inspect its contents with a ZIP tool. If the servlet class is missing in /WEB-INF/classes , or if the export causes an error, then the project is badly configured or some IDE/project configuration defaults have been mistakenly reverted (e.g. Project > Build Automatically has been disabled in Eclipse).

You also need to make sure that the project icon has no red cross indicating a build error. You can find the exact error in Problems view (Window > Show View > Other…). Usually the error message is fine Googlable. In case you have no clue, best is to restart from scratch and do not touch any IDE/project configuration defaults.

Test the servlet individually without any JSP/HTML page

Provided that the server runs on localhost:8080 , and that the WAR is successfully deployed on a context path of /contextname (which defaults to the IDE project name, case sensitive!), and the servlet hasn’t failed its initialization (read server logs for any deploy/servlet success/fail messages and the actual context path and servlet mapping), then a servlet with URL pattern of /servlet is available at http://localhost:8080/contextname/servlet .

You can just enter it straight in browser’s address bar to test it invidivually. If its doGet() is properly overriden and implemented, then you will see its output in browser. Or if you don’t have any doGet() or if it incorrectly calls super.doGet() , then a “HTTP 405: HTTP method GET is not supported by this URL” error will be shown (which is still better than a 404 as a 405 is evidence that the servlet itself is actually found).

Overriding service() is a bad practice, unless you’re reinventing a MVC framework — which is very unlikely if you’re just starting out with servlets and are clueless as to the problem described in the current question 😉

Regardless, if the servlet already returns 404 when tested invidivually, then it’s entirely pointless to try with a HTML form instead. Logically, it’s therefore also entirely pointless to include any HTML form in questions about 404 errors from a servlet.

Use domain-relative URL to reference servlet from HTML

Once you’ve verified that the servlet works fine when invoked individually, then you can advance to HTML. As to your concrete problem with the HTML form, the value needs to be a valid URL. The same applies to , ,

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This error indicates that the server could not find the desired resource. This resource can be any file such as JSP, HTML, or image resource. Usually, the resource is present, but it is referenced incorrectly. In most cases, you can fix this by correcting the URL. Here are three strategies you can use to look for errors:

1. Java servlets do not handle URL
2. Servlet forwarding the resource does not exist
3. URL is case-sensitive

1. Java servlets do not handle URL

Your @Webservlet() may handle for URL/name; however, the URL requested may be URL/this_name (different reference). You can fix this by correcting the reference URL or URL mapping.

In code, it may look something like this:

@WebServlet("/name")
public class Name extends HttpServlet {
...
}

However, your website requested /this_name instead of /name. One way you can correct this is by changing /name to /this_name in your URL mapping.

2. Servlet forwarding the resource does not exist

Make sure that the forwarded resource exists. If the resource you are trying to reference is not named correctly, you may also run into this problem. For instance, you are referencing signupForm.jsp, but the name of the resource is signup_Form.jsp. In code it may look something like this:

String signupForm= "frontend/signupForm.jsp";
RequestDispatcher dispatcher = request.getRequestDispatcher(signupForm);
dispatcher.forward(request, response);

You can fix this by correcting the servlet’s path which, in this case, would be to change signupForm.jsp to signup_Form.jsp.

3. URL is case-sensitive

If you typed the URL yourself, you might have mistyped it. Tomcat URLs are case-sensitive. For instance, signup is different than signUp. Make sure your URL is case-sensitive.