code: public static String toAbsoluteUrl(String absoluteBasePath, String relativePath) {
  		try {
  			URL absoluteUrl = new URL(absoluteBasePath);
  			return new URL(absoluteUrl, relativePath).toString();
  		} catch (Exception e) {
  			throw new UtilException(e, "To absolute url [{}] base [{}] error!", relativePath, absoluteBasePath);
  		}
  	}
docs: 相对URL转换为绝对URL
  
  @param absoluteBasePath 基准路径，绝对
  @param relativePath 相对路径
  @return 绝对URL