英文:
Trying to find the best way to check NullPointerException with nested multiple Object - Java 8
问题
以下是已经翻译好的内容：
我正在尝试找到在我陷入困境的情况下检查空指针异常的最佳方法。请支持我。
这是主要的类：
@Getter
@Setter
@AllArgsConstructor
public class Person {
private String name;
private Car car;
private Address address;
}
这是Car类：
@Setter
@Getter
@AllArgsConstructor
public class Car {
private String name;
private Insurance insurance;
}
这是Insurance类：
@Setter
@Getter
@AllArgsConstructor
public class Insurance {
private String name;
}
这是Address类：
@Setter
@Getter
@AllArgsConstructor
public class Address {
private String street;
}
这是显示信息的类（演示）：
@Setter
@Getter
public class InformationDto {
private String personName;
private String carName;
private String insuranceName;
private String streetName;
}
这是我尝试检查空指针异常的方式：
InformationDto dto = new InformationDto();
Optional.ofNullable(PERSON_CAR_NULL).map(i -> {
dto.setPersonName(i.getName());
Optional.ofNullable(i.getAddress()).map(e -> {
dto.setStreetName(e.getStreet());
return null;
});
return i.getCar();
}).map(i -> {
dto.setCarName(i.getName());
return i.getInsurance();
}).map(i -> {
dto.setInsuranceName(i.getName());
return null;
}).orElse(null);
请注意，这里的一些标识符（如PERSON_CAR_NULL）在提供的文本中并未提供定义，因此我保留了原始文本以供参考。
英文:
I am trying to find the best way to check null pointer exception with the situation that I have got stuck. Please support me.
This is the main Class:
@Getter
@Setter
@AllArgsConstructor
public class Person {
private String name;
private Car car;
private Address address;
}
This is Car class:
@Setter
@Getter
@AllArgsConstructor
public class Car {
private String name;
private Insurance insurance;
}
This is the Insurance class:
@Setter
@Getter
@AllArgsConstructor
public class Insurance {
private String name;
}
This is the Address class:
@Setter
@Getter
@AllArgsConstructor
public class Address {
private String street;
}
This is the Class to Display (demo):
@Setter
@Getter
public class InformationDto {
private String personName;
private String carName;
private String insuranceName;
private String streetName;
}
This is the way that I try to check null pointer exception:
InformationDto dto = new InformationDto();
Optional.ofNullable(PERSON_CAR_NULL).map(i -> {
dto.setPersonName(i.getName());
Optional.ofNullable(i.getAddress()).map(e -> {
dto.setStreetName(e.getStreet());
return null;
});
return i.getCar();
}).map(i -> {
dto.setCarName(i.getName());
return i.getInsurance();
}).map(i -> {
dto.setInsuranceName(i.getName());
return null;
}).orElse(null);
答案1
得分: 1
在我看来，一个简单的空值检查会使代码更易读。
Person person = new Person();
InformationDto dto = new InformationDto();
if (person != null) {
dto.setPersonName(person.getName());
if (person.getAddress() != null) {
dto.setStreetName(person.getAddress().getStreet());
}
if (person.getCar() != null) {
dto.setCarName(person.getCar().getName());
if (person.getCar().getInsurance() != null) {
dto.setInsuranceName(person.getCar().getInsurance().getName());
}
}
}
英文:
IMO, A simple null check will make the code more readable.
Person person = new Person();
InformationDto dto = new InformationDto();
if (person != null) {
dto.setPersonName(person.getName());
if (person.getAddress() != null) {
dto.setStreetName(person.getAddress().getStreet());
}
if (person.getCar() != null) {
dto.setCarName(person.getCar().getName());
if (person.getCar().getInsurance() != null) {
dto.setInsuranceName(person.getCar().getInsurance().getName());
}
}
}
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论