If I add @Builder to a class. The builder method is created.
Person.builder().name("john").surname("Smith").build();
I have a requirement where a particular field is mandatory. In this case, the name field is mandatory. Ideally, I would like to declare it like so.
Person.builder("john").surname("Smith").build();
When googling i found many alternatives like overriding the builder implementation as below:
@Builder
public class Person {
private String name;
private String surname;
public static PersonBuilder builder(String name) {
return new PersonBuilder().name(name);
}
}
And then use it like below:
Person p = Person.builder("Name").surname("Surname").build();
The problem with above approach is that it still provides the name() and PersonBuilder() method like below, which i don't want:
Person p = Person.builder("Name").surname("Surname").name("").build();
Person p = new Person.PersonBuilder().build;
Another approach is to add @lombok.nonnull check at name which will force to provide value for name while creating object. but it is a runtime check. it will not force me to provide value for name while creating object.
Is there any additional technique which lombok provides to achieve below:
Person p = Person.builder("Name").surname("Surname").build();
Note: The builder() and name() should not be exposed. The only way to create Person object should be either above or below:
Person p = Person.builder("Name").build();
You can't really do it with lombok, see the explanation from the library authors. But is it that complicated to roll this builder on your own?
public static class PersonBuilder {
private final String name;
private String surname;
PersonBuilder(String name) {
this.name = name;
}
public PersonBuilder surname(String surname) {
this.surname = surname;
return this;
}
public Person build() {
return new Person(name, surname);
}
}
with the same method that you already have:
public static PersonBuilder builder(String name) {
return new PersonBuilder(name);
}