/*created by fanqunsong
    Date : 2018/1/19
    Time : 16:14
    */
import org.junit.Test;

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

public class IpAdressUtils {
    public static boolean isIp(String ipAddress) {

        String ip = "([1-9]|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])(\\.(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])){3}";
        Pattern pattern = Pattern.compile(ip);
        Matcher matcher = pattern.matcher(ipAddress);
        return matcher.matches();

    }
    @Test
    public void test(){
        List<String> ipList = new ArrayList<String>();
        ipList.add("2.4.2.4");
        ipList.add("2.4.2.4.1");
        ipList.add("2.4.2");
        ipList.add("2.4.2.a");
        ipList.add("2.4.2.0");
        for(String str:ipList){
            if(isIp(str)){
                System.out.println(str);
            }
        }
    }
}

运行结果

2.4.2.4
2.4.2.0