Validate input to setDelimiter(String) for empty string

[mykolaf]

Signed-off-by: Mykola Faryma m.faryma@partner.samsung.com

The addition of String delimiter support opened a new opportunity to set the delimiter as empty string. This situation will result in NegativeArraySizeException (see example below). I propose to enhance argument checking in setDelimiter(String delimiter) to get explicit and helpful exception in such case.

Log:

Exception in thread "main" java.lang.NegativeArraySizeException: -1
        at org.apache.commons.csv.Lexer.<init>(Lexer.java:75)
        at org.apache.commons.csv.CSVParser.<init>(CSVParser.java:435)
        at org.apache.commons.csv.CSVParser.<init>(CSVParser.java:403)
        at org.apache.commons.csv.CSVParser.parse(CSVParser.java:303)
        at Test.main(Test.java:10)

Test code:

import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;

import java.io.StringReader;

public class Test {
    public static void main(String[] args) throws Exception {

        CSVParser.parse("abcd", CSVFormat.Builder.create().setDelimiter("").build());
    }
}