Assuming I have to read from a file, and then construct a java object out of it.
PersonData p = new PersonData();
p.setName(readTokenAsString());
p.setAge(AgeConverter.createFromDateOfBirth(readTokenAsString())); // this throws a checked exception if the date of birth is mal-formed.
//... a list of methods that throws exception as AgeConverter
Behavior I want: If one attribute has problem, just ignore it and keep process other attributes.
Solution I can think of:
try {
p.setAge1(...);
} catch (Exception e) {
//log and ignore
}
try {
p.setAge2(...);
} catch (Exception e) {
//log and ignore
}
//repeat for each attribute
Question:
Is there better way to do this to avoid repetition? Functional style maybe?
a) What's the best approach if I cannot modify PersonData
class.
b) What's the best approach if I can rewrite PersonData
class.
Given your current declaration, I would do it as follows.
Define a @FunctionalInterface
to which you can pass your I/O logic:
@FunctionalInterface
public interface CheckedSupplier<T> {
T getValue() throws Exception;
}
Define an utility method that consumes the @FunctionaInterface
:
public static final <T> T getValueWithDefault(CheckedSupplier<T> supplier, T defaultValue) {
try {
return supplier.getValue();
} catch (Exception e){
return defaultValue;
}
}
Use the utility method as follows:
PersonData p = new PersonData();
p.setName(getValueWithDefault(() -> readTokenAsString(), "default"));
p.setAge(getValueWithDefault(() -> AgeConverter.createFromDateOfBirth(readTokenAsString()), 0));
This should do the trick regardless of weather you want modify the PersonData
class or not.