如何将EL值分配给一个变量在Java

Question

我要分配该对象（$ {的categorys}）到ArrayList的

这是JSP

<% 

    ArrayList<Category> al =${categorys}; 

%>   

这是控制器

@RequestMapping(value = "/cat", method = RequestMethod.GET) 
public ModelAndView getTrancationHistory() { 

    ArrayList<Category> allData = service.viewAllCategory(); 
    //handle your code here... 
    System.out.println(allData); 
    for (Category allData1 : allData) { 
     System.out.println(allData1.getCategoryName()); 
    } 


    ModelAndView modelAndView = new ModelAndView(); 
    modelAndView.setViewName("WEB-INF/views/cat"); 
    modelAndView.addObject("categorys", allData); 
    return modelAndView; 
} 

Answer 1

你不能像使用jsp scriptlet那样使用${}。您必须手动获取它。你应该尝试这样的事情;

<% 
List<Category> al = (List<Category>) request.getAttribute("categorys"); 
%> 

或

<% 
List<Category> al = (List<Category>) pageContext.getAttribute("categorys", pageContext.REQUEST_SCOPE); 
%>