servlet中request里的arraylist的值如何让jsp获得
在jsp页面我写的是 ArrayList<Item> items = (ArrayList<Item>)request .getAttribute("payload2");
报错是这样的Type safety: Unchecked cast from Object to ArrayList<Item>
求大虾帮忙啊
在jsp页面我写的是 ArrayList<Item> items = (ArrayList<Item>)request .getAttribute("payload2");
报错是这样的Type safety: Unchecked cast from Object to ArrayList<Item>
求大虾帮忙啊
ArrayList<Item> items = new ArrayList<Item>();
request.setAttribute("payload2", items);
你的代码会报空指针的风险。
ArrayList<Item> items = request .getAttribute("payload2")==null?null:(ArrayList<Item>)request .getAttribute("payload2");