Boliball

package com.siro.tools;
 
public class JudgePhoneNum {
 
    private static String CMCC = "CMCC";
    private static String UNICOM = "UNICOM";
    private static String TELECOM = "TELECOM";
    private static String UNKNWON = "UNKNWON";
 
    private static boolean isNumeric(String msg) {
        for (int i = 0; i < msg.length(); i++) {
            if (java.lang.Character.isDigit(msg.charAt(i))) {
                continue;
            }
            return false;
        }
        return true;
    }
 
    public static String getOperater(String phoneNum) {
        String head3 = "";
        String head4 = "";
        phoneNum = phoneNum.trim();
 
        if (phoneNum == null || phoneNum.length() < 11) {
            return UNKNWON;
        } else {
            if (phoneNum.startsWith("+")) {
                phoneNum = phoneNum.substring(1);
            }
            if (phoneNum.startsWith("86")) {
                phoneNum = phoneNum.substring(2);
            }
        }
 
        if (phoneNum.length() != 11) {
            return UNKNWON;
        }
 
        if (!isNumeric(phoneNum)) {
            return UNKNWON;
        }
 
        head3 = phoneNum.substring(0, 3);
        head4 = phoneNum.substring(0, 4);
 
        if (head3.equals("135")
                || head3.equals("136")
                || head3.equals("137")
                || head3.equals("138")
                || head3.equals("139")
                || head3.equals("150")
                || head3.equals("151")
                || head3.equals("152")
                || head3.equals("157")
                || head3.equals("158")
                || head3.equals("159")
                || head3.equals("182")
                || head3.equals("187")
                || head3.equals("188")
                || head3.equals("147")) {
            return CMCC;
        }
        if (head4.equals("1340")
                || head4.equals("1341")
                || head4.equals("1342")
                || head4.equals("1343")
                || head4.equals("1344")
                || head4.equals("1345")
                || head4.equals("1346")
                || head4.equals("1347")
                || head4.equals("1348")) {
            return CMCC;
        }
        if (head3.equals("130")
                || head3.equals("131")
                || head3.equals("132")
                || head3.equals("145")
                || head3.equals("155")
                || head3.equals("156")
                || head3.equals("185")
                || head3.equals("186")) {
            return UNICOM;
        }
        if (head3.equals("133")
                || head3.equals("153")
                || head3.equals("180")
                || head3.equals("189")) {
            return TELECOM;
        }
        if (head4.equals("1349")) {
            return TELECOM;
        }
 
        return UNKNWON;
    }
 
    public static void main(String[] args) {
        System.out.println(JudgePhoneNum.getOperater("18243288210"));
    }
}