在Java中创建不可变对象的正确方法

public final class ImmutablePerson {
    private final String name;
    private final int age;

    public ImmutablePerson(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }
}

public final class ImmutablePerson {
    private final String name;
    private final int age;

    private ImmutablePerson(Builder builder) {
        this.name = builder.name;
        this.age = builder.age;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public static class Builder {
        private String name;
        private int age;

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

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

        public ImmutablePerson build() {
            return new ImmutablePerson(this);
        }
    }
}

import com.google.common.collect.ImmutableList;

public final class ImmutablePerson {
    private final String name;
    private final ImmutableList<String> hobbies;

    public ImmutablePerson(String name, List<String> hobbies) {
        this.name = name;
        this.hobbies = ImmutableList.copyOf(hobbies);
    }

    public String getName() {
        return name;
    }

    public ImmutableList<String> getHobbies() {
        return hobbies;
    }
}