本質——簡化物件建立的編碼

一、what

建立複雜物件的一種方式。

二、why

簡化了物件建立的步驟

提升了程式碼可讀性

物件的建立過程和表示分離

三、how

/**
 * @Description: 建造者模式
 * @date 2018-02-17 21:22
 */
@ToString
@Getter
@Setter
public class Person {
    private final String name;
    private int age;
    private String sex;
    private String father;
    private String mather;

    public static class Builder {
        private final String name;
        private int age;
        private String sex;
        private String father;
        private String mather;

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

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

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

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

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

    private Person(Builder builder){
        this.name = builder.name;
        this.sex = builder.sex;
        this.father = builder.father;
        this.mather = builder.mather;
        this.age = builder.age;
    }
}

public static void main(String[] args) throws IOException {
    Person person = new Person.Builder("張三").sex("男").age(23).Build();
    System.out.println(person);
}
 

簡單版

@Setter
@Getter
@ToString
public class Schema {

    /**
     * 意圖
     */
   @NonNull
    private String intent;
    /**
     * 分數
     */
    private int score;

    public Schema buildIntent(String intent){
        this.intent = intent;
        return this;
    }
    public Schema buildScore(int score){
        this.score = score;
        return this;
    }
}