注册用户时出现org.hibernate.exception.ConstraintViolationException

Question

我正在尝试创建注册过程，这是我的代码：

public class UserRegistrationDto {

private String firstName;
private String lastName;
private String password;
private String confirmPassword;
private String email;
private String confirmEmail;
private Boolean terms;
}

角色类别：

@Entity
public class Role {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String name;

用户类别：

@Entity
@Table(uniqueConstraints = @UniqueConstraint(columnNames = "email"))
public class User {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

private String firstName;
private String lastName;
private String email;
private String password;

@ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
@JoinTable(
        name = "users_roles",
        joinColumns = @JoinColumn(
                name = "user_id", referencedColumnName = "id"),
        inverseJoinColumns = @JoinColumn(
                name = "role_id", referencedColumnName = "id"))
private Collection<Role> roles;
}

服务：

@Service
public class UserServiceImpl implements UserService {

(...)
public User save(UserRegistrationDto registration){
    User user = new User();
    user.setFirstName(registration.getFirstName());
    user.setLastName(registration.getLastName());
    user.setEmail(registration.getEmail());
    user.setPassword(passwordEncoder.encode(registration.getPassword()));
    user.setRoles(Arrays.asList(new Role("ROLE_USER")));
    return userRepository.save(user);
}

private Collection<? extends GrantedAuthority> mapRolesToAuthorities(Collection<Role> roles){
    return roles.stream()
            .map(role -> new SimpleGrantedAuthority(role.getName()))
            .collect(Collectors.toList());
}
}

我得到了这个错误：

Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a]; constraint ["PRIMARY KEY ON PUBLIC.USER(ID)"; SQL statement: insert into user (email, first_name, last_name, password, id) values (?, ?, ?, ?, ?) [23505-196]]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement] with root cause org.h2.jdbc.JdbcSQLException: Naruszenie ograniczenia Klucza Głównego lub Indeksu Unikalnego: "PRIMARY KEY ON PUBLIC.USER(ID)" Unique index or primary key violation: "PRIMARY KEY ON PUBLIC.USER(ID)"; SQL statement: insert into user (email, first_name, last_name, password, id) values (?, ?, ?, ?, ?) [23505-196]

我不知道，我在哪里弄错了，我试图调试它，但是没有发现错误。 （我使用H2嵌入式数据库，仅用于培训）。 请帮忙。

Answer 1

您是否将数据库配置为自动生成id字段？ 如果不是，则每个对象中id的默认值将为0（长时的默认值）。

Answer 2

将子句AUTO_INCREMENT添加到表user的列ID的定义中。

实体用户中的注释@GeneratedValue（strategy = GenerationType.AUTO）表示在将用户插入到用户数据库时，数据库将自动生成id字段的值。