[Java] Regux判定IP

public class JavaApplication37 {

    private Pattern pattern;
    private Matcher matcher;

    private static final String IPADDRESS_PATTERN = "^([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\."
   + "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." + "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\."
   + "([01]?\\d\\d?|2[0-4]\\d|25[0-5])$";
    
    public JavaApplication37()
    {
        pattern = Pattern.compile(IPADDRESS_PATTERN);
    }
    public static void main(String[] args) {

        JavaApplication37 java7=new JavaApplication37();
        
        String testIP1="192.168.2.100";
        String testIP2="256.100.122.199";
        
       System.out.println("IP1 " +java7.validateIP(testIP1));
       System.out.println("IP2 " +java7.validateIP(testIP2));
    }

    public boolean validateIP(final String ip) {
  matcher = pattern.matcher(ip);
  return matcher.matches();
 }
}

輸出結果：

IP1 true
IP2 false

因為testIP2有一個值大於255, 並不合法。