Detect browser from user agent in hadoop pig UDF

Browser.java

package pigudf;

import java.io.IOException;
import org.apache.pig.EvalFunc;
import org.apache.pig.data.Tuple;

/**
 * Usage: 
 * log = LOAD logfile.txt AS (time:int, path:chararray, ua:chararray) 
 * log = FOREACH log GENERATE time, path, ua, pigudf(ua) AS browser;
 */
public class Browser extends EvalFunc<String> {

    @Override
    public String exec(Tuple input) throws IOException {
        if (input == null || input.size() == 0) {
            return "None";
        }
        String uaString = (String) input.get(0);
        if (uaString.matches(".*IEMobile.*")) {
            return "IEMobile";
        } else if (uaString.matches(".*MSIE 6.*")) {
            return "IE 6";
        } else if (uaString.matches(".*MSIE 7.*")) {
            return "IE 7";
        } else if (uaString.matches(".*MSIE 8.*")) {
            return "IE 8";
        } else if (uaString.matches(".*MSIE 9.*")) {
            return "IE 9";
        } else if (uaString.matches(".*Firefox.*")) {
            return "Firefox";
        } else if (uaString.matches(".*Chrome.*")) {
            return "Chrome";
        } else if (uaString.matches(".*Safari.*")) {
            return "Safari";
        }
        return "Unknown";
    }
}