docs: public String getFilePath() {
  
          // 不放到classpath, 则文件路径根据 userDefineDownloadDir 来设置
          if (!DisClientConfig.getInstance().enableLocalDownloadDirInClassPath) {
              return OsUtil.pathJoin(DisClientConfig.getInstance().userDefineDownloadDir, fileName);
          }
  
          if (targetDirPath != null) {
  
              if (targetDirPath.startsWith("/")) {
                  return OsUtil.pathJoin(targetDirPath, fileName);
              }
  
              return OsUtil.pathJoin(ClassLoaderUtil.getClassPath(), targetDirPath, fileName);
          }
  
          return OsUtil.pathJoin(ClassLoaderUtil.getClassPath(), fileName);
      }