数据库实体的Java构建器范例

public class User {
    private String name;
    private int age;
    private String email;

    // 私有构造函数，只能通过构建器创建对象
    private User(String name, int age, String email) {
        this.name = name;
        this.age = age;
        this.email = email;
    }

    // 构建器类
    public static class Builder {
        private String name;
        private int age;
        private String email;

        public Builder() {
        }

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

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

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

        public User build() {
            return new User(name, age, email);
        }
    }

    // Getter方法
    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public String getEmail() {
        return email;
    }
}

User user = new User.Builder()
    .setName("John")
    .setAge(25)
    .setEmail("john@example.com")
    .build();