How do I set a URL that includes an ampersand with Thymeleaf?

Question

I have something like:

Locale defaultLocale = Locale.getDefault();
final Context ctx = new Context(defaultLocale);
String url = getHost() + "/page?someId=" + some.getId() + "&someParam=" + Boolean.TRUE;
ctx.setVariable("url", url);

final String htmlContent = templateEngine.process("theHtmlPage", ctx);

But when I look at the resulting HTML to print url, it shows &amp instead of & in the URL.

Any suggestions?

I tried using backticks to escape the ampersand in the Java code, but it just printed those too. Looked around on SO, but didn't find much that was relevant. Also tried &

Update: Ok, this won't break the link, but Spring doesn't seem to resolve the parameter "someParam" as true without it.

Rendering tag:

<span th:utext="${url}"></span>

Output:

<span>http://localhost:8080/page?someId=1&amp;someParam=true</span>

This won't break the link and is the correct behavior in HTML. Check the other question. — Adrian Leonhard, Apr 06 '15 at 01:14
Updated. I understand that the resulting HTML must include the & as stated in the related question, but that doesn't help me generate the correct URL from the Java class. I'm trying to understand how people solve this, even with a work-around. — riddle_me_this, Apr 06 '15 at 01:21
You probably need to be using `utext` instead of `text` in your template. Show the rendering tag. — chrylis -cautiouslyoptimistic-, Apr 06 '15 at 01:23
Thymeleaf version? There were fixes in a very recent minor for this stuff. — chrylis -cautiouslyoptimistic-, Apr 06 '15 at 02:43
@chrylis can you please post an answer about the Thymeleaf version so that I may accept it? It works in 2.1.4.RELEASE! — riddle_me_this, Apr 06 '15 at 05:21
@JarrodRoberson This wasn't a duplicate; it was an issue with a Thymeleaf bug where escapes were handled an incorrect number of times, and the latest release version fixes the bug. — chrylis -cautiouslyoptimistic-, Apr 06 '15 at 06:11

score 3 · Answer 1 · edited Jun 20 '20 at 09:12

It's better to use the dedicated thymeleaf link url syntax.

If you want to construct and url with two parameters and set it to an href attribute you can do like this:

<a th:href="@{page(param1 = ${param1}, param2 = ${param2})}">link</a>

The generated html will be:

<a href="page?param1=val1&amp;param2=val2">link</a>

and the browser will request:

page?param1=val1&param2=val2

=== EDIT ===

To answer the downvote of dopatraman, I've just tested (again) my answer and it works well.

In my answer, the ampersand used as a parameters separator is automatically added by thymeleaf. And this added ampersand is html entity encoded, by thymeleaf, to be stored in the html.

If you have another ampersand inside param1 or param2, this ampersand should be html entity encoded inside the thymeleaf template. But it will appear percent encoded in the generated html.

Example (tested with thymeleaf 2.1.5.RELEASE):

param1 has value abc and param2 has value 12&3

Inside the thymeleaf template all ampersand must be encoded as html entity and we have:

<a th:href="@{page(param1 = ${'abc'}, param2 =${'12&amp;3'})}">link</a>

In the generated html, the ampersand used as a parameter separator is encoded as an html entity and the ampersand in the param2 value is percent-encoded by thymeleaf:

<a href="page?param1=abc&amp;param2=12%263">link</a>

When you click on the link, the browser will decode the html entity encoding but not the percent-encoding, and the url in the adress bar will be:

<a href="page?param1=abc&amp;param2=12%263">link</a>

Checking with wireshark, we obtain from the HTTP request:

GET /page?param1=abc&param2=12%263

this is incorrect. the browser request will keep the escaped token, making the query string argument `amp;param2` instead of `param2` — dopatraman, Sep 29 '16 at 17:45

score 3 · Answer 2 · answered Jul 22 '17 at 13:10

3

To avoid this kind of problems instead of '&' symbol you can use UTF code for that symbol, e.g in case of UTF-8 use '\u0026'.

answered Jul 22 '17 at 13:10

Meruzhan Kerobyan

31
1

score 2 · Accepted Answer · answered Apr 06 '15 at 05:27

2

Thymeleaf had a recent issue with encoding escapes, which has been fixed in 2.1.4.

answered Apr 06 '15 at 05:27

chrylis -cautiouslyoptimistic-

75,269
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How do I set a URL that includes an ampersand with Thymeleaf?

3 Answers3

Example (tested with thymeleaf 2.1.5.RELEASE):

Linked