content: /*
   * Copyright (C) 2019 the original author or authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.alibaba.nacos.address.util;
  
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  /**
   * Provides a unified tool class for address server parameter verification
   *
   * @author pbting
   * @date 2019-06-19 11:19 AM
   * @since 1.1.0
   */
  public class AddressServerParamCheckUtil {
  
      public static final String CHECK_OK = "ok";
  
      public static final String ILLEGAL_IP_PREFIX = "illegal ip: ";
  
      private static final String IP_REGEX = "(2(5[0-5]{1}|[0-4]\\d{1})|[0-1]?\\d{1,2})(\\.(2(5[0-5]{1}|[0-4]\\d{1})|[0-1]?\\d{1,2})){3}";
  
      private static final Pattern IP_PATTERN = Pattern.compile(IP_REGEX);
  
      public static String checkIps(String... ips) {
  
          if (ips == null || ips.length == 0) {
  
              return CHECK_OK;
          }
          // illegal response
          StringBuilder illegalResponse = new StringBuilder();
          for (String ip : ips) {
              Matcher matcher = IP_PATTERN.matcher(ip);
              if (matcher.matches()) {
                  continue;
              }
              illegalResponse.append(ip + ",");
          }
  
          if (illegalResponse.length() == 0) {
              return CHECK_OK;
          }
  
          return ILLEGAL_IP_PREFIX + illegalResponse.substring(0, illegalResponse.length() - 1);
      }
  }
  