SpringBoot virtual threads - JWT verify and MySQL query

application.properties

server.port=3000
spring.datasource.url= jdbc:mysql://localhost:3306/testdb?useSSL=false&allowPublicKeyRetrieval=true
spring.datasource.username= dbuser
spring.datasource.password= dbpwd
spring.jpa.hibernate.ddl-auto= update
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL8Dialect

User.java

package com.example.demo;

import jakarta.persistence.Entity;
import jakarta.persistence.Table;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;

@Entity
@Table(name = "users")
public class User {
  @Id
  private String email;

  private String first;

  private String last;

  private String city;

  private String county;

  private int age;

  public String getId() {
    return email;
  }

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

  public String getFirst() {
    return first;
  }

  public void setFirst(String name) {
    this.first = name;
  }

  public String getLast() {
    return last;
  }

  public void setLast(String name) {
    this.last = name;
  }

  public String getEmail() {
    return email;
  }

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

  public String getCity() {
    return city;
  }

  public void setCity(String city) {
    this.city = city;
  }

  public String getCounty() {
    return county;
  }

  public void setCounty(String county) {
    this.county = county;
  }

  public int getAge() {
    return age;
  }

  public void setAge(int age) {
    this.age = age;
  }
}

UserApplication.java

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.embedded.tomcat.TomcatProtocolHandlerCustomizer;
import org.springframework.context.annotation.Bean;
import java.util.concurrent.Executors;

@SpringBootApplication
public class UserApplication {

    public static void main(String[] args) {
        SpringApplication.run(UserApplication.class, args);
    }

    @Bean
    public TomcatProtocolHandlerCustomizer<?> protocolHandlerVirtualThreadExecutorCustomizer() {
        return protocolHandler -> {
            protocolHandler.setExecutor(Executors.newVirtualThreadPerTaskExecutor());
        };
    }
}

UserController.java

package com.example.demo;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.http.ResponseEntity;
import org.springframework.http.HttpStatus;
import org.springframework.http.HttpHeaders;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.beans.factory.annotation.Autowired;
import java.util.Optional;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.Jws;
import io.jsonwebtoken.Claims;
import io.jsonwebtoken.SignatureAlgorithm;
import io.jsonwebtoken.security.Keys;
import java.security.Key;
import com.example.demo.UserRepository;
import com.example.demo.User;

@RestController
public class UserController {

    @Autowired
    UserRepository userRepository;

    private SignatureAlgorithm sa = SignatureAlgorithm.HS256;
    private String jwtSecret = System.getenv("JWT_SECRET");

    @GetMapping("/")
    public User handleRequest(@RequestHeader(HttpHeaders.AUTHORIZATION) String authHdr) {
        String jwtString = authHdr.replace("Bearer","");
        Claims claims = Jwts.parser()
            .setSigningKey(jwtSecret.getBytes())
            .parseClaimsJws(jwtString).getBody();

        Optional<User> user = userRepository.findById((String)claims.get("email"));
        return user.get();
    }
}

UserRepository.java

package com.example.demo;

import org.springframework.data.repository.CrudRepository;
import com.example.demo.User;

public interface UserRepository extends CrudRepository<User, String> {

}