here is my UserRepository.java

package com.example.arvrapp.repository;

import com.example.arvrapp.model.User;
import org.springframework.data.jpa.repository.JpaRepository;

public interface UserRepository extends JpaRepository<User, Long> {
    User findByUsername(String username);
}
here is my usercontroller.java

package com.example.arvrapp.controller;

import com.example.arvrapp.model.User;
import com.example.arvrapp.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
@RestController
@RequestMapping("/users")
public class UserController {

    @Autowired
    private UserRepository userRepository;

    @PostMapping("/signup")
    public User signUp(@RequestBody User user) {
        return userRepository.save(user);
    }

    @PostMapping("/login")
    public String login(@RequestBody User user) {
        User existingUser = userRepository.findByUsername(user.getUsername());
        if (existingUser != null && existingUser.getPassword().equals(user.getPassword())) {
            return "Login successful!";
        } else {
            return "Invalid credentials!";
        }
    }
}

User.java 

package com.example.arvrapp.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String username;
    private String password;
    private String email;

    // Getters and setters
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

user service.java

package com.example.arvrapp.service;
import com.example.arvrapp.model.User;
import com.example.arvrapp.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
@Service
public class UserService {
    @Autowired
    private UserRepository userRepository;

    public User registerUser(User user) {
        return userRepository.save(user);
    }

    public User findUserByUsername(String username) {
        return userRepository.findByUsername(username);

when i try to run this is in local host
im getting like this

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Sat Jul 13 13:54:21 IST 2024
There was an unexpected error (type=Not Found, status=404).