@AllArgsConstructor @NoArgsConstructor

//@Data 生成getter,setter ,toString等函数
//@NoArgsConstructor 生成无参构造函数
//@AllArgsConstructor //生成全参数构造函数

//@Data 生成getter,setter等函数
//@NoArgsConstructor 生成无参构造函数
//@AllArgsConstructor //生成全参数构造函数
@Data  
@AllArgsConstructor
@NoArgsConstructor
public class test  implements Serializable {
    private static final long serialVersionUID = 1L;
    /**出口订单*/
    private Order  exportOrder;
    /**出口撤销*/
    private Order exportInvtCancel;
}


首先,用到的几个注解:

    • @Data
      使用这个注解,就不用再去手写Getter,Setter,equals,canEqual,hasCode,toString等方法了,注解后在编译时会自动加进去。
    • @AllArgsConstructor
      使用后添加一个构造函数,该构造函数含有所有已声明字段属性参数
    • @NoArgsConstructor
      使用后创建一个无参构造函数
    • @Builder
      关于Builder较为复杂一些,Builder的作用之一是为了解决在某个类有很多构造函数的情况,也省去写很多构造函数的麻烦,在设计模式中的思想是:用一个内部类去实例化一个对象,避免一个类出现过多构造函数,

然后,通过一个简单的代码例子说明:

1)首先,建立一个简单的类,并用lombok进行注解:注意这是注解前的代码,可以与后面贴出的注解生成的代码进行比较

@Data //生成getter,setter等函数
@AllArgsConstructor //生成全参数构造函数
@NoArgsConstructor//生成无参构造函数
@Builder
public class test1 {
    String name;
    String age;
    String sex;
}
  • 1

2)测试入口:

 public static void main(String[] args) {
 //使用@Builder注解后,可以直接通过Builder设置字段参数
        test1 t1=new test1.test1Builder()
                .name("wang")
                .age("12")
                .sex("man")
                .build();

        System.out.println("name is"+t1.getName()+'\n'+"age is :"+t1.getAge());

    }

 

3)通过查看编译后的类,比较注解前后的代码量,发现会省去了很多代码的书写:

public class test1 {
    String name;
    String age;
    String sex;

    public static test1.test1Builder builder() {
        return new test1.test1Builder();
    }

    public String getName() {
        return this.name;
    }

    public String getAge() {
        return this.age;
    }

    public String getSex() {
        return this.sex;
    }

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

    public void setAge(String age) {
        this.age = age;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public boolean equals(Object o) {
        if (o == this) {
            return true;
        } else if (!(o instanceof test1)) {
            return false;
        } else {
            test1 other = (test1)o;
            if (!other.canEqual(this)) {
                return false;
            } else {
                label47: {
                    Object this$name = this.getName();
                    Object other$name = other.getName();
                    if (this$name == null) {
                        if (other$name == null) {
                            break label47;
                        }
                    } else if (this$name.equals(other$name)) {
                        break label47;
                    }

                    return false;
                }

                Object this$age = this.getAge();
                Object other$age = other.getAge();
                if (this$age == null) {
                    if (other$age != null) {
                        return false;
                    }
                } else if (!this$age.equals(other$age)) {
                    return false;
                }

                Object this$sex = this.getSex();
                Object other$sex = other.getSex();
                if (this$sex == null) {
                    if (other$sex != null) {
                        return false;
                    }
                } else if (!this$sex.equals(other$sex)) {
                    return false;
                }

                return true;
            }
        }
    }

    protected boolean canEqual(Object other) {
        return other instanceof test1;
    }

    public int hashCode() {
        int PRIME = true;
        int result = 1;
        Object $name = this.getName();
        int result = result * 59 + ($name == null ? 43 : $name.hashCode());
        Object $age = this.getAge();
        result = result * 59 + ($age == null ? 43 : $age.hashCode());
        Object $sex = this.getSex();
        result = result * 59 + ($sex == null ? 43 : $sex.hashCode());
        return result;
    }

    public String toString() {
        return "test1(name=" + this.getName() + ", age=" + this.getAge() + ", sex=" + this.getSex() + ")";
    }

    @ConstructorProperties({"name", "age", "sex"})
    public test1(String name, String age, String sex) {
        this.name = name;
        this.age = age;
        this.sex = sex;
    }

    public test1() {
    }

    public static class test1Builder {
        private String name;
        private String age;
        private String sex;

        test1Builder() {
        }

        public test1.test1Builder name(String name) {
            this.name = name;
            return this;
        }

        public test1.test1Builder age(String age) {
            this.age = age;
            return this;
        }

        public test1.test1Builder sex(String sex) {
            this.sex = sex;
            return this;
        }

        public test1 build() {
            return new test1(this.name, this.age, this.sex);
        }

        public String toString() {
            return "test1.test1Builder(name=" + this.name + ", age=" + this.age + ", sex=" + this.sex + ")";
        }
    }
}
  • 1
  • 2

总结:lombok注解使用起来会很方便,可以多去了解不同注解的作用。
另贴一些相关的博客:
lombok 安装使用及一些注解功能:
https://blog.csdn.net/motui/article/details/79012846
java Builder:
http://www.cnblogs.com/moonz-wu/archive/2011/01/11/1932473.html
https://www.cnblogs.com/begin1949/p/4930896.html

posted @ 2020-12-30 11:45  风骚羊肉串  阅读(1765)  评论(0编辑  收藏  举报