java - 在jsp上创建List时出现异常

Question

我在 jsp 上创建列表时遇到问题。我不确定它是否是一个错误(尽管不太可能)或者我实现它的方式存在一些问题。当我尝试在列表对象中存储值时，出现此异常

type Exception report

messageInternal Server Error

descriptionThe server encountered an internal error that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: PWC6033: Error in Javac compilation for JSP

PWC6199: Generated servlet error:
source value 1.5 is obsolete and will be removed in a future release

PWC6199: Generated servlet error:
target value 1.5 is obsolete and will be removed in a future release

PWC6199: Generated servlet error:
To suppress warnings about obsolete options, use -Xlint:-options.

PWC6197: An error occurred at line: 18 in the jsp file: /OrderCheckOut.jsp
PWC6199: Generated servlet error:
diamond operator is not supported in -source 1.5
  (use -source 7 or higher to enable diamond operator)

note The full stack traces of the exception and its root causes are available in the GlassFish Server Open Source Edition 4.1 logs.

首先，我认为 session 对象可能没有保存该值，因此我检索了字符串中的值并且它工作正常。但我遇到了列表问题。下面是我的 Jsp 代码。` <% 尝试 { 购物车 displayCart = (Cart) session.getAttribute("getValue");

         String firstname=displayCart.getProdRefCode().toString();
          //This is causing problem I suppose
         ArrayList<String>ProdRefCode=new ArrayList<>();
         ProdRefCode.add(firstname);
        } catch (Exception ex) {
    %><p> There is some problem..check..!
        <%
            }
        %>`

谁能帮我把..

任何帮助将不胜感激..

谢谢

Answer 1

你的堆栈跟踪清楚地说明了为什么会发生这个问题。您可能使用 Java 5，但钻石运算符是 Java 7 的功能。所以，有两种解决方案

1. 更新至 Java 7

2. 不要使用像下面这样的声明的菱形运算符。

   List<String> ProdRefCode = new ArrayList<String>();