遇到多个构造器参数时要考虑用构建器

/**
 * Created by chengkang
 * 2018/9/19 下午4:03
 */
public class User {
    private final String name;//required
    private final int year;//optional
    private final int sexNum;//optional
    private final String job;//optional

    public static class Builder{
        private final String name;//required

        private int year = 0;//optional
        private int sexNum = 0;//optional
        private String job = "";//optional
        public Builder(String name){
            this.name = name;
        }
        public Builder year(int val){
            year = val;
            return this;
        }
        public Builder sexNum(int val){
            sexNum = val;
            return this;
        }
        public Builder job(String val){
            job = val;
            return this;
        }

        public User build(){
            return new User(this);
        }
    }
    private User(Builder builder){
        name = builder.name;
        year = builder.year;
        job = builder.job;
        sexNum = builder.sexNum;
    }

    public static void main(String[] args) {
        User user = new Builder("ck").year(24).sexNum(1).job("IT").build();
        System.out.println(user.name);
        System.out.println(user.year);
        System.out.println(user.sexNum);
        System.out.println(user.job);
    }
}