Getting HTTP Status 404 – Not Found : The origin server did not find a current representation for the target resource or is not willing to disclose

Question

I was following this tutorial on RESTful Web Services https://www.tutorialspoint.com/restful/restful_first_application.htm I've followed the same steps but the resource is not being found when I hit the URI through postman http://localhost:8080/UserManagement/rest/UserService/users

This is web.xml file stored inside WEB-INF folder under web app, the rest of the files have same content of the tutorial, I'm a bit new to web services please help with what could be going wrong here

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee      http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
   <display-name>User Management</display-name>
   <servlet>
      <servlet-name>Jersey RESTful Application</servlet-name>
      <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
      <init-param>
         <param-name>jersey.config.server.provider.packages</param-name>
         <param-value>com.tutorialspoint</param-value>
      </init-param>
   </servlet>
   <servlet-mapping>
      <servlet-name>Jersey RESTful Application</servlet-name>
      <url-pattern>/rest/*</url-pattern>
   </servlet-mapping>
</web-app>

Server - apache-tomcat-10.1.10

Jersey - 2.40.0

Jdk 19

UserService

package com.tutorialspoint;  

import java.util.List; 
import javax.ws.rs.GET; 
import javax.ws.rs.Path; 
import javax.ws.rs.Produces; 
import javax.ws.rs.core.MediaType;  
@Path("/UserService") 

public class UserService {  
   UserDao userDao = new UserDao();  
   @GET 
   @Path("/users") 
   @Produces(MediaType.APPLICATION_XML) 
   public List<User> getUsers(){ 
       System.out.println("Inside Service Class");
      return userDao.getAllUsers(); 
   }  
}

User

package com.tutorialspoint;  

import java.io.Serializable;  
import javax.xml.bind.annotation.XmlElement; 
import javax.xml.bind.annotation.XmlRootElement; 
@XmlRootElement(name = "user") 

public class User implements Serializable {  
   private static final long serialVersionUID = 1L; 
   private int id; 
   private String name; 
   private String profession;  
   public User(){} 
    
   public User(int id, String name, String profession){  
      this.id = id; 
      this.name = name; 
      this.profession = profession; 
   }  
   public int getId() { 
      return id; 
   }  
   @XmlElement 
   public void setId(int id) { 
      this.id = id; 
   } 
   public String getName() { 
      return name; 
   } 
   @XmlElement
   public void setName(String name) { 
      this.name = name; 
   } 
   public String getProfession() { 
      return profession; 
   } 
   @XmlElement 
   public void setProfession(String profession) { 
      this.profession = profession; 
   }   
} 

UserDao

package com.tutorialspoint;  

import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException;  
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.ObjectInputStream; 
import java.io.ObjectOutputStream; 
import java.util.ArrayList; 
import java.util.List;  

public class UserDao { 
@SuppressWarnings("unchecked")
public List<User> getAllUsers(){ 
      
      List<User> userList = null; 
      try { 
         File file = new File("Users.dat"); 
         if (!file.exists()) { 
            User user = new User(1, "Mahesh", "Teacher"); 
            userList = new ArrayList<User>(); 
            userList.add(user); 
            saveUserList(userList); 
         } 
         else{ 
            FileInputStream fis = new FileInputStream(file); 
            ObjectInputStream ois = new ObjectInputStream(fis); 
            userList = (List<User>) ois.readObject(); 
            ois.close(); 
         } 
      } catch (IOException e) { 
         e.printStackTrace(); 
      } catch (ClassNotFoundException e) { 
         e.printStackTrace(); 
      }   
      return userList; 
   } 
   private void saveUserList(List<User> userList){ 
      try { 
         File file = new File("Users.dat"); 
         FileOutputStream fos;  
         fos = new FileOutputStream(file); 
         ObjectOutputStream oos = new ObjectOutputStream(fos); 
         oos.writeObject(userList); 
         oos.close(); 
      } catch (FileNotFoundException e) { 
         e.printStackTrace(); 
      } catch (IOException e) { 
         e.printStackTrace(); 
      } 
   }    
}

Folder Structure

Libraries

Also, getting this exception for the first time when I hit the URI

Message Class [org.glassfish.jersey.servlet.ServletContainer] is not a Servlet

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

Exception

jakarta.servlet.ServletException: Class [org.glassfish.jersey.servlet.ServletContainer] is not a Servlet
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:676)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341)
    org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:391)
    org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)
    org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:894)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1741)
    org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
    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:1589)
Root Cause

java.lang.ClassCastException: class org.glassfish.jersey.servlet.ServletContainer cannot be cast to class jakarta.servlet.Servlet (org.glassfish.jersey.servlet.ServletContainer is in unnamed module of loader org.apache.catalina.loader.ParallelWebappClassLoader @a82c5f1; jakarta.servlet.Servlet is in unnamed module of loader java.net.URLClassLoader @3b95a09c)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:676)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341)
    org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:391)
    org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)
    org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:894)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1741)
    org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
    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:1589)

Am I messing up with the versions?

Answer 1

Am I messing up with the versions?

Yes, the Jersey version 2.40 won't work with Tomcat 10.1 Try Jersey 3.1.2 instead.