Why trim is not working?

Question

I am trying to trim leading whitespaces from the string and I do not know what is wrong with my approach, any suggestions would be appreciated ?

Code:

this.poNumber = poNumber.equals("") ? poNumber : poNumber.trim();

am reading poNumber from csv file as "     IG078565 and IG083060 " and output also am getting same value with same whitespaces, not sure why ?

Updated

Adding complete method for better context:

public BillingDTO(String currency, String migrationId, String chargeId, String priceId, String poNumber, String otc,
            String billingClassId, String laborOnly) {
        super();
        this.currency = currency.equals("") ? currency : currency.trim();
        this.migrationId = migrationId.equals("") ? migrationId : migrationId.trim();
        this.chargeId = chargeId.equals("") ? chargeId : chargeId.trim();
        this.priceId = priceId.equals("") ? priceId : priceId.trim();
        this.poNumber = poNumber.equals("") ? poNumber : poNumber.trim();
            //poNumber.trim();
        //System.out.println("poNumber:"+this.poNumber.trim());
        //this.poNumber = poNumber.equals("") ? poNumber : poNumber.trim();
        this.otc = otc.equals("") ? otc : otc.trim();
        this.billingClassId = billingClassId.equals("") ? billingClassId : billingClassId.trim();
        this.laborOnly = laborOnly.equals("") ? "N" : laborOnly;
    }

Thanks.

Answer 1

Update It appears your whitespace is not a whitespace (ascii=32). Yours is with code 160, which is a no-breaking space. trim() does not handle it. So you must do something like this:

this.poNumber = poNumber.replace(String.valueOf((char) 160), " ").trim();

You'd better create an utility - YourStringUtils.trim(string) and there perform the two operations - both .trim() and the replace(..)

---

Original answer:

Just use this.poNumber = poNumber.trim();

If there is a possibility for poNumber to be null, then you can use the null-safe this.poNumber = StringUtils.trim(poNumber); from commons-lang.

You can also use trimToEmpty(..) from the same class, if you want null to be transformed to an empty string.

If you don't want to rely on commons-lang, then just add an if-clause:

if (poNumber != null) {
    this.poNumber = poNumber.trim();
}

As noted in the comments under the question - make sure you are checking the right variable after the trimming. You should check the instance variable. Your parameter (or local variable, I can't tell) does not change, because strings are immutable.

Answer 2

Are you sure you're reading the right variable for your output? You have 'poNumber', which is the original untrimmed string, and 'this.poNumber', which would get the trimmed string.