HTML tag stored in ModelMap not interpreted as HTML by the browser

Question

I have a spring controller with the following code :

@RequestMapping(value="/getMessage.htm", method=RequestMethod.POST)
protected String uploadFile(ModelMap model){

     //... other codes

    model.addAttribute("theMessage", "Hello world <b>how are you</b> today?");

    return "the-view";
}

In the client side (JavaScript), I show this message using the following code :

document.getElementById('theMessageSpan').innerHTML = '<c:out value="${theMessage}"/>';

But when it is displayed, it shows a string literal

Hello world <b>how are you</b> today?

I need to show the message as :

Hello world how are you today?

I tried using apache commons' StringEscapeUtils.unescapeHtml before putting the text in the ModelMap, but the result is just the same.

Any thoughts?

Answer 1

I believe by default <c:out> escapes XML. You'll need to explicitly tell it not to with

<c:out escapeXml="false" value="${theMessage}"/>

Can't find newer docs, but see here. Among the attributes, you have

escapeXml

Determines whether characters <,>,&,'," in the resulting string should be converted to their corresponding character entity codes. Default value is true.