Java String 字符串截取和获取文件的上级目录

  public String test() {
		String root = ServletActionContext.getServletContext().getRealPath("/");
		String root1 = "te/st/21.jpg";
		File cat=new File(root);

		System.out.println("root="+root);
		System.out.println("parent="+cat.getParent());
		System.out.println("="+root1.substring(root1.indexOf('s')));
		return "success";
	}

• 测试结果：