content: package openjoe.smart.sso.server.util;
  
  import org.springframework.util.CollectionUtils;
  import org.springframework.util.StringUtils;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  import java.util.function.Function;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  /**
   * 转换工具类
   *
   * @author Joe
   */
  public class ConvertUtils {
  
      /**
       * List对象转换
       *
       * @param collection 集合
       * @param function   对象转换方法
       * @return
       */
      public static <T, E> List<E> convert(Collection<T> collection, Function<? super T, ? extends E> function) {
          if (CollectionUtils.isEmpty(collection)) {
              return Collections.emptyList();
          }
          return collection.stream().map(function::apply).collect(Collectors.toList());
      }
  
      public static List<Long> convertToIdList(final String ids) {
          return StringUtils.hasLength(ids) ? Stream.of(ids.split(",")).filter(s -> StringUtils.hasLength(s)).map(s -> Long.valueOf(s.trim()))
                  .collect(Collectors.toList())
                  : Collections.emptyList();
      }
  }