Thymeleaf-Spring BigDecimal formatting with #NumberFormat adds extra symbols - spring-mvc

Question

I'm using Thymeleaf 2.1.2.RELEASE with Spring MVC 4.0.4.RELEASE
I have a dynamic form that I use to add new order lines to an order.
The problem I am facing is that each time I add a line and the content is re-rendered then an extra symbol is added before the currency symbol on the price column of each of the previous lines.
So if I add three rows i get
£22.00
£22.00
£22.00
The price field is BigDecimal with #NumberFormat(style = NumberFormat.Style.CURRENCY) so Spring should handle the conversion.
<div>
<label th:text="#{order.lines}">Order Lines</label>
<table id="addTable" dt:table="true" dt:sort="false" dt:paginate="false" dt:info="false" dt:lengthchange="false">
<thead>
<tr>
<th th:text="#{order.lines.head.linenum}">line</th>
<th th:text="#{order.lines.head.product}">Product</th>
<th th:text="#{order.lines.head.description}">Description</th>
<th th:text="#{order.lines.head.quantity}">Quantity</th>
<th th:text="#{order.lines.head.price}">Price</th>
<th>
<button type="submit" name="addLine" th:text="#{order.line.add}">Add line</button>
</th>
</tr>
</thead>
<tbody>
<tr th:each="line,lineStat : *{lines}">
<td th:text="${lineStat.count}">1</td>
<td>
<input type="text" th:field="*{lines[__${lineStat.index}__].productIdentifier}"
th:errorclass="fieldError"/>
</td>
<td>
<input type="text" th:field="*{lines[__${lineStat.index}__].description}"
th:errorclass="fieldError"/>
</td>
<td>
<input type="text" th:field="*{lines[__${lineStat.index}__].quantity}"
th:errorclass="fieldError"/>
</td>
<td>
<input type="text" th:field="*{{lines[__${lineStat.index}__].price}}"
th:errorclass="fieldError"/>
</td>
<td>
<button type="submit" name="removeLine" th:value="${lineStat.index}"
th:text="#{order.line.remove}">Remove line
</button>
</td>
</tr>
</tbody>
</table>
</div>
This is then backed by class with
public class OrderLine implements Serializable {
#NotEmpty
private String description;
#NotNull
#NumberFormat(style = NumberFormat.Style.CURRENCY)
private BigDecimal price;
#NotEmpty
private String productIdentifier;
#NotNull
#Min(value = 1)
private Integer quantity;
and then in my controller
#RequestMapping(value="/customer/orders", params={"addLine"})
public String addLine(final Order order, final BindingResult bindingResult) {
order.getLines().add(new OrderLine());
return "customer/orders";
}
The html page aleady includes
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
and the character encoding servlet filter is set up as below
#Override
protected Filter[] getServletFilters() {
CharacterEncodingFilter characterEncodingFilter = new CharacterEncodingFilter();
characterEncodingFilter.setEncoding("UTF-8");
characterEncodingFilter.setForceEncoding(true);
return new Filter[] {characterEncodingFilter};
}
Further to this from using Fiddler I can see that the response header to the dandelion datatables ajax request is incorrectly encoded as ISO-88591. I'm using datatables-thymeleaf 0.93 with datatables 1.9.4
From experimenting if I set thymeleaf encoding, the spring servlet filter and the html meta tag to ISO-88591 then the currency symbol appears correctly rendered although I would like this to work with UTF-8
Eventually I found an answer in this post CharacterEncodingFilter don't work together with Spring Security 3.2.0 provided by #Christian Nilsson. Basically I needed to force the character encoding filter to be registered using the onStartup method rather than the usual getServletFilters.