UserRestController.java

package com.mif13.authServer.controllers;

import com.mif13.authServer.dao.UsersDao;
import com.mif13.authServer.model.User;
import java.util.Optional;
import java.util.regex.PatternSyntaxException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("users")
public class UserRestController {

    private final UsersDao usersRepo;

    @Autowired
    public UserRestController(UsersDao usersRepo) {
        this.usersRepo = usersRepo;
    }

    @GetMapping(value = "/{id}", produces = "application/json")
    public ResponseEntity<User> getUser(@PathVariable String id) {
        ResponseEntity<User> response;

        Optional<User> optionalUser = usersRepo.get(id);
        if (optionalUser.isPresent()) {
            User user = optionalUser.get();
            response = new ResponseEntity<>(user, HttpStatus.OK);
        } else {
            response = new ResponseEntity<>(HttpStatus.NOT_FOUND);
        }

        return response;
    }

    @PostMapping
    public ResponseEntity<Void> createUser(@RequestParam("login") String login,
        @RequestParam("password") String password) {
        ResponseEntity<Void> response;

        try {
            if (verifyLogin(login) && verifyPassword(password)) {
                Optional<User> optionalUser = usersRepo.get(login);
                if (optionalUser.isEmpty()) {
                    User user = new User(login, password);
                    usersRepo.save(user);
                    response = new ResponseEntity<>(HttpStatus.CREATED);
                } else {
                    response = new ResponseEntity<>(HttpStatus.FORBIDDEN);
                }
            } else {
                response = new ResponseEntity<>(HttpStatus.BAD_REQUEST);
            }
        } catch (PatternSyntaxException e) {
            response = new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
        }

        return response;
    }

    private boolean verifyLogin(String login) throws PatternSyntaxException {
        String regex = "^[a-zA-Z][a-zA-Z0-9._-]{3,20}$";
        return login.matches(regex);
    }

    private boolean verifyPassword(String pwd) throws PatternSyntaxException {
        String regex =
            "^(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.*[!@#&()–[{}]:;',?/*~$^+=<>]).{8,25}$";
        return pwd.matches(regex);
    }

}