Lombok - @AllArgsConstructor

The last constructor generating annotation is the @AllArgsConstructor. The @AllArgsConstructor will generate a constructor with 1 parameter for each field in your class. Fields which are marked with @NonNull result in null checks on those parameters.

Let's take a look at the following example:

Here is the code for our Car class. What do you think the constructor will look like in the compiled code?

import lombok.AllArgsConstructor;
import lombok.NonNull;
import java.time.LocalDate;

@AllArgsConstructor
public class Car {
    @NonNull
    final String licensePlate;
    String brand;
    LocalDate manufacturingDate;
    boolean inUse;
    int count;
}

After compiling the code by running mvn clean install, our car.class file will look like the following:

package nl.emsnsoftware.entity;

import java.time.LocalDate;
import lombok.NonNull;

public class Car {
    @NonNull
    final String licensePlate;
    String brand;
    LocalDate manufacturingDate;
    boolean inUse;
    int count;

    public Car(@NonNull String licensePlate, String brand, LocalDate manufacturingDate, boolean inUse, int count) {
        if (licensePlate == null) {
            throw new NullPointerException("licensePlate is marked non-null but is null");
        } else {
            this.licensePlate = licensePlate;
            this.brand = brand;
            this.manufacturingDate = manufacturingDate;
            this.inUse = inUse;
            this.count = count;
        }
    }
}

We can notice that a constructor with 5 parameters with generated and that corresponds with the number of instance variables of the Car class.

Lombok also generated a null check for the licensePlate field since it is marked with @NonNull annotation.

Thank you for reading my blog. Please make sure to check out the other Lombok annotations articles by visiting the Lombok section of my blog.