Java String to complete mathematical sum

Question

In java, I am currently in the process of trying to find a way to do mathematical sums by typing in text to a JTextField, putting it into a String, and converting it to an int a

Answer 1

See to java.util.regex.Matcher or java.util.regex.Pattern For ex:

import java.util.regex.Matcher; import java.util.regex.Pattern;

public class IpDnsValidateUtils {
    public static final int MAX_DNS_LEN = 39;
    private static final Pattern ptrnIp = Pattern
        .compile("^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$"); 
    private static final Pattern ptrnDomainName = Pattern
        .compile("^([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\\-]{0,61}[a-zA-Z0-9])(\\.([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\\-]{0,61}[a-zA-Z0-9])){0,}[.][a-zA-Z]{2,5}$"); 

    public static boolean isValidIp(String value, boolean emptyTrue) {  boolean ret = false;    if (!value.isEmpty() || !emptyTrue) {
        Matcher m = ptrnIp.matcher(value);
        ret = m.matches();  } else {
        ret = true;     }   return ret;
    }

    public static boolean isValidDns(String value, boolean emptyTrue) {     boolean ret = false;    if (!value.isEmpty() || !emptyTrue) {
        Matcher m = ptrnDomainName.matcher(value);
        ret = m.matches();  } else {
        ret = true;     }   return ret;
    } }

or StringTokenizer class