content: package org.ruoyi.common.core.utils.ip;
  
  import cn.hutool.core.io.FileUtil;
  import cn.hutool.core.io.resource.ClassPathResource;
  import cn.hutool.core.util.ObjectUtil;
  import lombok.extern.slf4j.Slf4j;
  import org.lionsoul.ip2region.xdb.Searcher;
  import org.ruoyi.common.core.exception.ServiceException;
  import org.ruoyi.common.core.utils.file.FileUtils;
  
  import java.io.File;
  
  /**
   * 根据ip地址定位工具类，离线方式
   * 参考地址：<a href="https://gitee.com/lionsoul/ip2region/tree/master/binding/java">集成 ip2region 实现离线IP地址定位库</a>
   *
   * @author lishuyan
   */
  @Slf4j
  public class RegionUtils {
  
      private static final Searcher SEARCHER;
  
      static {
          String fileName = "/ip2region.xdb";
          File existFile = FileUtils.file(FileUtil.getTmpDir() + FileUtil.FILE_SEPARATOR + fileName);
          if (!FileUtils.exist(existFile)) {
              ClassPathResource fileStream = new ClassPathResource(fileName);
              if (ObjectUtil.isEmpty(fileStream.getStream())) {
                  throw new ServiceException("RegionUtils初始化失败，原因：IP地址库数据不存在！");
              }
              FileUtils.writeFromStream(fileStream.getStream(), existFile);
          }
  
          String dbPath = existFile.getPath();
  
          // 1、从 dbPath 加载整个 xdb 到内存。
          byte[] cBuff;
          try {
              cBuff = Searcher.loadContentFromFile(dbPath);
          } catch (Exception e) {
              throw new ServiceException("RegionUtils初始化失败，原因：从ip2region.xdb文件加载内容失败！" + e.getMessage());
          }
          // 2、使用上述的 cBuff 创建一个完全基于内存的查询对象。
          try {
              SEARCHER = Searcher.newWithBuffer(cBuff);
          } catch (Exception e) {
              throw new ServiceException("RegionUtils初始化失败，原因：" + e.getMessage());
          }
      }
  
      /**
       * 根据IP地址离线获取城市
       */
      public static String getCityInfo(String ip) {
          try {
              ip = ip.trim();
              // 3、执行查询
              String region = SEARCHER.search(ip);
              return region.replace("0|", "").replace("|0", "");
          } catch (Exception e) {
              log.error("IP地址离线获取城市异常 {}", ip);
              return "未知";
          }
      }
  
  }
  