Access.java

package link.colon.authorize;

import lombok.Data;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import java.io.Serializable;

@Data
@Entity
@Table(name = "accesses")
public class Access implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @Column(name="token")
    public String token;

    @Column(name="access_name")
    public String accessName;

}

AccessCRUD.java

package link.colon.authorize;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

import java.util.Optional;

@Repository
public interface AccessCRUD extends CrudRepository<Access, Long> {

    Optional<Access> findByToken(final String token);

}

AM.java

package link.colon.controller;

import link.colon.authorize.AccessCRUD;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.Optional;

@Slf4j
@RestController
@RequiredArgsConstructor
class AM {

    private final AccessCRUD crud;

    @GetMapping(value = "/verify/{token}")
    private String verify(@PathVariable("token") final String token) {
        log.info("Authoen by {}", token);
        return crud.findByToken(token).map(a -> a.accessName)
                .orElse(null);
    }

}