所以这是为构建Human
而编写的现有代码片段(如电影:)matrix
if (gender.equals("male")){
return Human.builder()
.gender('male')
.name('abc')
.speaks("english")
.alive(true)
.build();
}else{
return Human.builder()
.gender('female')
.name('abcd')
.speaks("english")
.alive(true)
.build();
}
如果你看一下,这段代码在属性分配中有很多冗余,可以最小化。现在想象一下 10 个这样的条件(这里,它只有 2 个!(,无论你尝试什么,它最终都会导致看起来丑陋的冗余代码。
我尝试在线搜索大量资源,但找不到任何按照构建器设计构建对象的方法。我想在这里实现的(减少代码冗余(如下所示:
Human human = Human.builder()
.speaks("english")
.alive(true);
if (gender.equals("male")){
human = human // or just human.gender('male').name('abc'); no assignment
.gender('male')
.name('abc');
}else{
human = human // or just human.gender('female').name('abcd'); no assignment
.gender('female')
.name('abcd');
}
return human.build();
这可以通过龙目岛实现吗,或者有人知道在这里构建对象的更好方法?
如果值得,我在drop-wizard
使用龙目岛的生成器:
import lombok.Builder;
import lombok.ToString;
@Builder
@ToString
public class Human {
private String name;
private String gender;
private String speaks;
private boolean alive;
public static void main(String[] args) {
HumanBuilder humanBuilder = Human.builder();
String gender = "female";
humanBuilder
.speaks("english")
.alive(true);
if("male".equals(gender)){
humanBuilder
.gender("male")
.name("abc");
}else{
humanBuilder
.gender("female")
.name("abcd");
}
Human human = humanBuilder.build();
System.out.println(human);
}
}
结果:
Human(name=abcd, gender=female, speaks=english, alive=true)
您可以使用以下任一方法来删除代码冗余并提供清晰度:
选项 1:
Human human = Human.builder()
.gender(gender.equals("M")?"male":(gender.equals("F")?"female":"transgender"))
.name("abc")
.speaks("english")
.alive(true)
.address(Optional.ofNullable(address).orElse(defaultAddress))
.build();
选项 2:
Human human = Human.builder()
.gender(getGender(gender))
.name("abc")
.speaks("english")
.alive(true)
.address(Optional.ofNullable(address).orElse(defaultAddress))
.build();
public static String getGender(String gender){
return gender.equals("M")?"male":(gender.equals("F")?"female":"transgender");
}
选项 3:
Human.HumanBuilder humanBuilder = Human.builder();
humanBuilder.name("abc").speaks("english").alive(true);
if(gender.equals("M")){
humanBuilder.gender("male");
}else {
humanBuilder.gender("female");
}
Human human = humanBuilder.build();
我个人更喜欢选项 2,因为它使代码更干净。
希望这有帮助。