打印从Spring MVC Controller发送的String数组，在javascript中仅显示“ toJSON”

Question

I have a list of String (department names) passed from a controller to a JSP page. I need to get each individual name and use it as the key to a map (the map value will be a list of employees for that department). However, when I do alert for each department name, I got a string "toJSON". How do I get each name in a readable string? Some department name contain special character like apostrophes, slash. Many Thanks!

Controller:

@RequestMapping(value = "/getDepartment", method = { RequestMethod.POST, RequestMethod.GET })
 public ModelAndView getDepartment()
 {
     ModelAndView mv = new ModelAndView();
     mv.addObject("depNameList", depNameList); // depNameList is a type of List<String> 
     mv.setViewName("displayDepartment");
     return mv;
  }

JSP:

 $(document).ready(function() 
 {
    var depArr = "${depNameList}";    
    alert(depArr); // this printed a list of department names
    for ( var i in depArr)
    { 
         alert("i=" + i); // this printed "i=toJSON"
         alert("i=" + JSON.stringfy(i)); // this didn't get invoked.
    }
  });

Here is how I solved the issue with Remdo's suggestion (Thank you!). I didn't change on the controller side.

  var depArr =[]
 <c:forEach items="${depNameList}" var="depName">
      depArr.push("${depName}");
  </c:forEach>

Answer 1

alert("i=" + JSON.stringfy(i)); // this didn't get invoked.

because i is not a JSON object, depArr has a string not array of string,

 mv.addObject("depNameList", depNameList); // depNameList is a type of List<String> 

if you print depNameList in console, output would be like:

[a, b, c, d] //this is invalid JSON, missing qoutes( " OR ' )

Also, If you run with above statement compiler will throw a error like:

Expecting 'STRING', 'NUMBER', 'NULL', 'TRUE', 'FALSE', '{', '[', ']'

Solution :

Change:

var depArr = "${depNameList}";

To:

var depArr =[]
<c:forEach items="${depNameList}" var="depName">
     depArr.push(\"${depName}\");
</c:forEach>

See Also:

• Java EE 5 tutorial - JavaServer Pages Standard Tag Library