CODEWITHSUNDEEP
javaspring-bootspring-transactions
Hai Hoang
Hai Hoang

Reputation: 1257

Spring @Transactional cause NoClassDefFoundError

A guy ask me for help him resolve a strange bug in security service of his spring boot app, after hours of trail I manage to fix the bug but I really have no idea what happen. Please look at these classes:

Class User : user infomation in database

@Getter
@Setter
@Entity
@Table(name = "user", uniqueConstraints = {@UniqueConstraint(columnNames = {"user_name"})})
public class User extends DateAudit implements Serializable {
  // Id, username, password and constructor... not really important

  @ManyToMany(fetch = FetchType.LAZY)
  @JoinTable(name = "user_roles", joinColumns = @JoinColumn(name = "user_id"), inverseJoinColumns = @JoinColumn(name = "role_id"))
  private Set<Role> role = new HashSet<>();
}

Class UserDto : implement Spring's interface for manage user credential

@Getter
@Setter
@AllArgsConstructor
public class UserDto implements org.springframework.security.core.userdetails.UserDetails {
  private long id;
  private String Username;
  @JsonIgnore
  private String password;
  private Collection<? extends GrantedAuthority> authorities;

  public static UserDto create(User user) {
    List<GrantedAuthority> authorities = user.getRole().stream()
      .map(role -> new SimpleGrantedAuthority(role.getName().name())).collect(Collectors.toList());

    return new UserDto(user.getId(), user.getUserName(), user.getPassword(), authorities);
  }

  // implement interface's methods, only getters, not important
}

Class CustomUserService : Auth service

@Service
public class CustomUserService implements org.springframework.security.core.userdetails.UserDetailsService {
  private final UserRepository userRepository;

  @Autowired
  public CustomUserService(UserRepository userRepository) {
     this.userRepository = userRepository;
  }

  @Override
  @Transactional
  public UserDetails loadUserByUsername(String userName) throws UsernameNotFoundException {
    User user = userRepository.findUserByUserName(userName).orElseThrow(() -> {
    return null;
    });
    return UserDto.create(user);
  }
}

Full source code can be found here (it is only a simple spring boot app with some classes) : https://github.com/raizo000/admin_project (his repo uses embedded tomcat, I've tried to change it to jetty but it is not the cause)

When I run code the first time with these 3 classes. The line 

return UserDto.create(user);

Give me a NoClassDefFoundError :

WARN 7252 --- [qtp223566397-22] org.eclipse.jetty.server.HttpChannel     : /login

java.lang.NoClassDefFoundError: com/example/admin/dto/UserDto
    at com.example.admin.services.CustomUserService.loadUserByUsername(CustomUserService.java:28) ~[classes/:na]
    at com.example.admin.services.CustomUserService$$FastClassBySpringCGLIB$$b9234a59.invoke(<generated>) ~[classes/:na]
....

I have checked the jar file, there is a UserDto.class file in the right directory.

Remove the @Transactional help fix the error but cause another lazily initialize error and I end up change fetch = FetchType.LAZY in User class to fetch = FetchType.EAGER as a quick fix.

Why adding Transactional can cause a NoClassDefFoundError? Do remove Transactional is the right solution or there is a better fix?

Upvotes: 0

Views: 214

Answers (1)

Jonathan JOhx
Jonathan JOhx

Reputation: 5968

When a class is not found, the first thing that you should make is clean and build. Because, the last build is saving some dependency. So the @Transactional @interface was not found in some corrupt package. A rebuild(clean build) solves it.

Upvotes: 1

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