Lombok 中带有静态助手的自定义 setter 和构造函数

Question

I want to use Custom setter and constructor with static helper in Lombok:

@SuperBuilder(toBuilder = true)
public class Teacher extends User {
}


@Data
@SuperBuilder(toBuilder = true)
@NoArgsConstructor
@AllArgsConstructor
@JsonInclude(NON_NULL)
public class User implements Employee {
    private static final PasswordEncoder ENCODER = new BCryptPasswordEncoder();

    private String username;
    private String password;

    User(String username, String password) {
        System.out.println("*** test ***");

    }
}

but when I create a Teacher object it seems that the constructor is not called because I don't see the test message in the console

Teacher.builder()
 .username("username").password("pwd").build();

Answer 1

The point of the Builder pattern is almost always to return an immutable object from a builder object that is inherently mutable. The static helper you're referring to is the Builder pattern factory method used to create the User object. You shouldn't need to create a setter for User, instead User should be not defined with @Data.

If you need to call some method after construct of the User or Employee object just add a function to the respective class and call it after construct. Hiding work inside of a constructor other than initializing class members can be dangerous because you're hiding functionality and if it's a private method that functionality cannot be overridden.

    @SuperBuilder(toBuilder = true)
    public static class Teacher extends User {

    }

    @AllArgsConstructor
    @SuperBuilder(toBuilder = true)
    public static class User implements Employee {

        private final String username;

        private final String password;
    }

    public static void main(String[] args) {
        Teacher teacher = Teacher.builder()
                .username("username").password("pwd").build();

        System.out.println(teacher.toString());
    }

    interface Employee {

    }