Question

How to handle null when using Pattern.compile? I’m using the following line to compare strings:

Pattern.compile(Pattern.quote(s2), Pattern.CASE_INSENSITIVE).matcher(s1).find()

There are some cases where s1 can be null and obviously it throws NullPointerException. I know this could be handled by another if condition to s1, but I would like to know is there’s an alternate solution.

EDIT

Iterator iter = sampleList().iterator();
while (iter.hasNext()) {
    SampleObj so = (SampleObj) iter.next();
    if (!s1.equalsIgnoreCase("")) {
        if (Pattern.compile(Pattern.quote(s1), Pattern.CASE_INSENSITIVE).matcher(so.getS1()).find())
            match = true;
        else
            match = false;
    }
    if (!s3.equalsIgnoreCase("")) {
        if (Pattern.compile(Pattern.quote(s3), Pattern.CASE_INSENSITIVE).matcher(so.getS3()).find())
            match = true;
        else
            match = false;
    }
}

s1 and s3 are inputs which are matched over iterator.

Answer 1

Pattern.matcher() will always throw a NullPointerException when you pass in null, so: no, there is no other way, you’ll have to check for null explicitly.