Or - why does it say my spring context xml is invalid on <aop:

I've been trying to add the @Configurable to a spring project.

This means that I had to have a tag that looks like

<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:aop="http://www.springframework.org/schema/aop"
   xmlns:tx="http://www.springframework.org/schema/tx"
   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
                       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
                       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd">

(here the important lines are the xmlns:aop and the aop schema location) and the following needs to be in the beans XML

<aop:spring-configured/>

In addition - I added the spring-aspects dependency in my maven pom

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-aspects</artifactId>
  <version>2.0.6</version>
</dependency>

Trouble was that the test was throwing an XML error

org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 13 in XML document from class path resource [directory.xml] is invalid; nested exception is org.xml.sax.SAXParseException: cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'aop:spring-configured'.

A lot of googling suggested that it was using a non-schema compliant XML parser - but I'd made sure that it was using the latest schema supporting xerces.

It turns out that the XSD resolver is trying to find the XSD on the classpath - and it can't find it unless you also have spring-aop

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-aop</artifactId>
  <version>2.0.6</version>
</dependency>

in your dependency list. I personally feel that this is a confusing error message - but there you go.

All kudos to Kaare Nilsen for finally spotting what was missing.