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If I specify @AllArgsConstructor using Lombok, it will generate a constructor for setting all the declared (not final, not static) fields. Is it possible to omit some field and this leave generated constructor for all other fields?

user3656823
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5 Answers5

173

No that is not possible. There is a feature request to create a @SomeArgsConstructor where you can specify a list of involved fields.

Full disclosure: I am one of the core Project Lombok developers.

TuGordoBello
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Roel Spilker
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145

Alternatively, you could use @RequiredArgsConstructor. This adds a constructor for all fields that are either @NonNull or final.

See the documentation

dermoritz
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    This is a nice workaround, using @NonNull. But be aware that this does not work with fields having default-values. – eeezyy Jun 28 '19 at 14:50
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    This worked well for me, and I even marked the omitted field with `@Transient` to avoid it being tracked by java persistence layer since it was in my DAO. – Encryption Jan 13 '20 at 14:43
15

Just in case it helps, initialized final fields are excluded.

@AllArgsConstructor
class SomeClass {
    final String s;
    final int i;
    final List<String> list = new ArrayList<>(); // excluded in constructor
}

var x = new SomeClass("hello", 1);

It makes sense especially for collections, or other mutable classes.

This solution can be used together with the other solution here, about using @RequiredArgsConstructor:

@RequiredArgsConstructor
class SomeClass2 {
    final String s;
    int i; // excluded because it's not final
    final List<String> list = new ArrayList<>(); // excluded because it's initialized
}

var x = new SomeClass2("hello");
Ferran Maylinch
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    Important addition: "initialized **final** fields are excluded" -> If the field is only initialized but not final the constructor (generated by AllArgsConstructor) will be generated with this field as well :) – oruckdeschel Jan 06 '21 at 09:21
  • Hi I wanna ask if there's any idea how to generate two types of constructors, for example one contains string s and int i and one contains string s and string F . – Compte Gmail Oct 31 '21 at 11:00
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    Lombok is intended to generate code for common cases, not for specific scenarios. You should code your particular constructors explicitly. – Ferran Maylinch Nov 01 '21 at 19:23
  • Your answer helped a ton: in case the fields you want to exclude are final because they are constants. – avi.elkharrat Dec 16 '21 at 10:07
13

A good way to go around it in some cases would be to use the @Builder

TuGordoBello
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enkara
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  • see an example here: https://stackoverflow.com/a/39920328/363573 – Stephan Apr 12 '20 at 16:51
  • Lets say "_a_ way" but not "a _good_ way". If you want an `AllArgsConstructor` to guarantee that the user provides all (required) members a std builder is _not_ the way to do it. – towi Jul 01 '21 at 09:32
  • I said in some cases, and I still stand by it – enkara Jul 02 '21 at 11:51
8

This can be done using two annotations from lombok @RequiredArgsConstructor and @NonNull.

Please find the example as follows

package com.ss.model;

import lombok.*;

@Getter
@Setter
@RequiredArgsConstructor
@ToString
public class Employee {

    private int id;
    @NonNull
    private String firstName;
    @NonNull
    private String lastName;
    @NonNull
    private int age;
    @NonNull
    private String address;
}

And then you can create an object as below

Employee employee = new Employee("FirstName", "LastName", 27, "Address");
Shubhasish Bhunia
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