这是一个常见的问题。基本上，你需要暴露一个 asBuilder() . 此示例方法获取一个用传递的示例的值初始化的生成器。

Car existingCar = Car.builder()......build() ;

//new car with same props as existing but the speed
Car existingCarButFaster = existingCar.asBuilder()
                           .speed(existingCar.speed * 2)
                           .build();

实施 asBuilder() 应该直截了当。
而且，您似乎正在生成许多样板文件。如果将代码库与代码生成器连接起来对您来说不是问题，那么可以使用 Lombok 绝大多数项目使用的库。

/**
     * If true, generate an instance method to obtain a builder that is initialized with the values of this instance
     * Legal only if {@code @Builder} is used on a constructor, on the type itself, or on a static method that returns
     * an instance of the declaring type.
     * 
     * @return Whether to generate a {@code toBuilder()} method.
     */
    boolean toBuilder() default false;

添加方法 initFrom(Car) 给你的 Builder 类，它调用给定 Car 示例并用返回值初始化其参数。后来对 Builder 的方法可能会用正确的值覆盖这些值。
接下来你可以介绍一个 TemplateCar 类作为新的父类 Car 它允许使用不完整的参数集进行构建，并且有自己的 Builder （当然，您需要将上述方法更改为 initFrom(TemplateCar) ).
这就是你要“模板”的意思吗？

谢谢你的回答！我决定使用@tquadrat的解决方案，但要扩展一下。我决定为初始化构建器的类添加一个接口。
汽车.java

public class Car {

private final String model;
private final int color;
private final int speed;

public Car(String model, int color, int speed) {
    this.model = model;
    this.color = color;
    this.speed = speed;
}

//..Getters

public static class Builder {
    private String model;
    private int color;
    private int speed;

    public Builder initFrom(@NotNull CarBuilderInitializer initializer) {
        Builder builder = initializer.initBuilder(this);
        this.model = builder.getModel();
        this.color = builder.getColor();
        this.speed = builder.getSpeed();
        return this;
    }

    public Builder model(String model) {
        this.model = model;
        return this;
    }

    public Builder color(int color) {
        this.color = color;
        return this;
    }

    public Builder speed(int speed) {
        this.speed = speed;
        return this;
    }

    public Car build() {
        return new Car(model, color, speed);
    }
}}

carbuilderinitializer.java文件

public interface CarBuilderInitializer {
    Car.Builder initBuilder(Car.Builder builder);
}

yourcustombuildercar.java

public class YourCustomBuilderCar implements CarBuilderInitializer {
    @Override
    public  initBuilder(@NotNull Car.Builder builder) {
        return builder
                .model("Audi");
                .color(Color.RED);
    }
}

客户端代码：car1=new car.builder（）.initfrom（new yourcustombuildercar（））.speed（200）.build（）；