Lombok

builder.java

import lombok.experimental.Builder;

@Builder
public class Person {

    private int id;
    private String firstname;
    private String lastname;
    private double age;

}

pom.xml

<dependency>
	<groupId>org.projectlombok</groupId>
	<artifactId>lombok</artifactId>
	<version>1.14.6</version>
	<scope>provided</scope>
</dependency>

tostring.java

import lombok.Data;
import lombok.ToString;

@Data
@ToString(of={"firstname", "lastname"})
public class Person {

    private int id;
    private String firstname;
    private String lastname;
    private double age;

}