如何在JavaScript中访问Servlet变量 [英] How to access a servlet variable inside javascript

问题描述

我有一个servlet，该servlet的变量包含一个JSON字符串.

I have a servlet which has a variable which holds a JSON string.

JSONObject obj = new JSONObject();
obj.put("parameter", jsonList);
request.setAttribute("jsonstring", obj.toString());
RequestDispatcher rd = request.getRequestDispatcher("/file.jsp");
rd.forward(request, response);

现在，我将请求和响应对象转发到包含JS文件的JSP页面. 我该如何访问JS文件中的 jsonstring 变量的值.因为我需要使用jQuery进一步解析JSON字符串.

Now I am forwarding my request and response objects to a JSP page which contains a JS file. How can I access the value of jsonstring variable inside the JS file.As I need to parse my JSON string further using jQuery.

我尝试在JS文件中执行此操作，就像在网上的一些帖子中看到的那样.但这似乎对我不起作用.

I tried doing this in my JS file as I saw in some of the posts online.But it seems like its not working for me.

var test = '<%=request.getAttribute("jsonstring")%>'

请指导我.谢谢.

推荐答案

如果JSP文件使用<script>标记加载外部JavaScript文件，则如下所示:

If the JSP file uses a <script> tag to load an external JavaScript file, something like this:

<script type="text/javascript" src="js/yourFile.js"></script>

然后它将不起作用.您拥有的是一个JSP脚本，它仅在JSP文件执行期间具有某些含义.该yourFile.js文件不会在服务器端进行解析，因为它不需要被解析.只有浏览器会知道如何使用<script>标记，并向服务器发出请求以加载JavaScript.

then it won't work. What you have is a JSP scriptlet which only means something during the execution of the JSP file. That yourFile.js file won't be parsed server-side because it doesn't need to be. Only the browser will know what to do with the <script> tag and issue a request to the server to load the JavaScript.

在这些情况下，您可以在JSP中执行以下操作:

In these cases what you can do is something like this inside your JSP:

<script type="text/javascript">
    var test = <%=request.getAttribute("jsonstring")%>;
</script>
<script type="text/javascript" src="js/yourFile.js"/></script>

由于JSP脚本位于您的JSP文件中，因此实际上可以正确处理它，而是输出对象/数组的有效JSON，以存储在全局范围内的test变量中，然后您可以在.

Since the JSP scriptlet is inside your JSP file it now actually gets processed correctly, and instead outputs the valid JSON for the object/array to store in the globally scoped test variable, which you can then refer to inside yourFile.js.

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