构建器模式中的java类型推断

public class Person {
    private String name;
    private int age;
    private String gender;

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

    // Getters and setters

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

        public Builder() {
        }

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

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

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

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

Person person = new Person.Builder()
        .name("John")
        .age(30)
        .gender("Male")
        .build();