Question

将JSP Integer数组传递给javascript时遇到问题。 JSP数组已正确填充。我可以在JSP代码中正确呈现JSP数组的元素。但是，当我将JSP数组传递给我的javascript函数时，我的javascript代码中的值是未定义的。

JSP Code Snippet

....

<! This works correctly !>
<div class="col content-M">
  <p>JSP Array Population Test</p>
    ${daynumbers[2]}
</div>

<! This does not work !>
<div class="col content-L">
  <p>Pass a JSP Integer Array to setDayValues</p>
  <script type="text/javascript">setDayValues(${daynumbers});</script>
  <div id="columnchart_values"></div> 
</div>

....

JavaScript代码段

var a = Array(6);

function setDayValues(values) {
    a[0] = values[0];
    a[1] = values[1];
    a[2] = values[2];
    a[3] = values[3];
    a[4] = values[4];
    a[5] = values[5];     
}

function simpleColumnChart() {

    var data = google.visualization.arrayToDataTable([
         ['Element', 'Density', { role: 'style' }],
         ['1', a[0], 'blue'],
         ['2', a[1], 'blue'],
         ['3', a[2], 'blue'],
         ['4', a[3], 'blue'],
         ['5', a[4], 'blue'],
         ['6', a[5], 'blue']
    ]);

  ....

}

就像我说的那样，[x]在javascript中是一个unifined。

Answer 1

我认为问题在于您理解$ {daynumbers}错误的方式。 $ {daynumbers}将返回什么？一个javascript数组？尝试console.log（$ {daynumbers}），你会发现你的问题，因为你可以看到$ {daynumbers [0]}的值，你可能会返回一个javascript不理解的java数组对象，所以你可以尝试将$ {daynumbers}转换为json字符串，并解析它。

Answer 2

The problem is that ${daynumbers} is resulting in invalid JavaScript being sent to the client.

If you want to output the array of integers, use Arrays.toString:

<script type="text/javascript">setDayValues(${Arrays.toString(daynumbers)});</script>

The client browser will see

<script type="text/javascript">setDayValues([1, 2, 3, 4, 5, 6]);</script>

...(with your actual values, of course), which is valid JavaScript defining an array with those entries.

Then in setDayNumbers, there's no need to copy them, just use the array passed into setDayNumbers:

function setDayNumbers(values) {
    a = values;
}

麻烦将HTML Integer数组传递给Javascript函数

2 个答案: