Validate parsed fields using Univocity Parser

Question

I wanted to know if there is a way to check and validate a field when using the CsvRoutines package. Basically I want to process a row if the first column has only numbers and skip/possibly throw an exception otherwise. I'm guessing @Validate annotation released in 2.7.0 can be used to achieve this. But I would like to know if there is any other way to achieve the same with earlier versions like 2.5.9?

Answer 1

Author of the library here. There's no other way other than updating to the latest version. Is there any reason in particular why you can't upgrade?

Update: you can put the @Parsed annotations on the class' getters or setters and perform the validations in them. That is probably the cleanest way to go about it. For example:

class Test {

    private Integer number;

    //accepts a String here... so this is straight from the parser before it tries to convert anything into an integer - which lets you validate or throw a custom exception
    @Parsed
    void setNumber(String number){
        try{
            this.number = Integer.valueOf(number);
        } catch(NumberFormatException e){
            throw new IllegalArgumentException(number + " is not a valid integer");
        }
    }

}

Another alternative is to use a custom conversion class. Copy the code of class ValidatedConversion, used in the newest version, then create subclass like:

public static class RangeLimiter extends ValidatedConversion {
    int min;
    int max;

    public RangeLimiter(String[] args) {
        super(false, false); //not null, not blank
        min = Integer.parseInt(args[0]);
        max = Integer.parseInt(args[1]);
    }

    protected void validate(Object value) {
        super.validate(value); //runs the existing validations for not null and not blank
        int v = ((Number) value).intValue();
        if (v < min || v > max) {
            throw new DataValidationException("out of range: " + min + " >= " + value + " <=" + max);
        }
    }
}

Now on your code, use this:

@Parsed(field = "number")
@Convert(conversionClass = RangeLimiter.class, args = {"1", "10"}) //min = 1, max = 10
public int number;

I didn't test this against an old version. I think you may need to set flag applyDefaultConversion=false in the @Parsed annotation, and make your conversion class convert a String into an int in addition to run the validations.

All in all, that's quite a bit of work that can easily be avoided just by upgrading to the latest version.