public class User {
  @NotEmpty
  private String email;
  @JsonProperty(access = Access.WRITE_ONLY)
  @NotEmpty
  private String password;

  // Getters and setters
  ...
}

@Path("/register")
@POST
public Response register(@Valid User user) {
  ...
}

"{"errors":["password may not be empty"]}"

public class GroupValidationTest {


    public static void main(String[] args) {
        Validator v = Validators.newValidator();


        Model m = new Model();
        m.user = "Harry";
        m.password = "Potter";

        Set<ConstraintViolation<Model>> validate = v.validate(m, INPUT.class);
        System.out.println(validate.size());

        validate = v.validate(m, INPUT.class, OUTPUT.class);
        System.out.println(validate.size());

        validate = v.validate(m, OUTPUT.class);
        System.out.println(validate.size());

        m.password = null;

        validate = v.validate(m, INPUT.class, OUTPUT.class);
        System.out.println(validate.size());

        validate = v.validate(m, OUTPUT.class);
        System.out.println(validate.size());
    }

    public static class Model {

        @NotEmpty(groups={INPUT.class, OUTPUT.class})
        public String user;

        @NotEmpty(groups={INPUT.class})
        public String password;

    }

    public interface INPUT {}
    public interface OUTPUT {}

}

0 -> Full object, validate INPUT
0 -> Full object, validate INPUT + OUTPUT
0 -> Full object, validate OUTPUT
1 -> null password, validate INPUT + OUTPUT
0 -> null password, validate OUTPUT