//@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;
}
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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()+'
'+"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 + ")";
}
}
}
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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