I need to check if some value is null or not. And if its not null then just set some variable to true. There is no else statement here. I got too many condition checks like this.
Is there any way to handle this null checks without checking all method return values?
if(country != null && country.getCity() != null && country.getCity().getSchool() != null && country.getCity().getSchool().getStudent() != null .....) {
isValid = true;
}
I thought directly checking variable and ignore NullpointerException. Is this a good practice?
try{
if(country.getCity().getSchool().getStudent().getInfo().... != null)
} catch(NullPointerException ex){
//dont do anything.
}
No, it is generally not good practice in Java to catch a NPE instead of null-checking your references.
You can use Optional for this kind of thing if you prefer:
if (Optional.ofNullable(country)
.map(Country::getCity)
.map(City::getSchool)
.map(School::getStudent)
.isPresent()) {
isValid = true;
}
or simply
boolean isValid = Optional.ofNullable(country)
.map(Country::getCity)
.map(City::getSchool)
.map(School::getStudent)
.isPresent();
if that is all that isValid is supposed to be checking.
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