If you have a Spring 2 application using MuleESB in 2.x version, and you initialize the mule using SpringXmlConfigurationBuilder, you may notice that this simply doesn’t work in Spring 3 ;)

I mean something like this:

public void startMule() throws MuleException {
    SpringXmlConfigurationBuilder builder = 
      new SpringXmlConfigurationBuilder(muleConfigResources,applicationContext);
    MuleContextFactory muleContextFactory = new DefaultMuleContextFactory();
    muleContext = muleContextFactory.createMuleContext(builder);
    runtimeConfig(muleContext); 
    muleContext.start();
}

After a lot of struggling I’ve discovered that this is because the DefaultBeanDefinitionDocumentReader interface in spring has been changed from:

protected BeanDefinitionParserDelegate createHelper(XmlReaderContext readerContext, 
    Element root) {}

to:

protected BeanDefinitionParserDelegate createHelper(XmlReaderContext readerContext, 
    Element root, BeanDefinitionParserDelegate parentDelegate) {}

I don’t want to migrate my whole application MuleESB 3.x, what seems to have Spring 3 compatible classes, so some fixes to existing mule initialization were required here. For those interested in the same, here is the solution:

public void startMule() throws MuleException {
    Spring3XmlConfigurationBuilder builder = 
      new Spring3XmlConfigurationBuilder(muleConfigResources,applicationContext);
    MuleContextFactory muleContextFactory = new DefaultMuleContextFactory();
    muleContext = muleContextFactory.createMuleContext(builder);
    runtimeConfig(muleContext); 
    muleContext.start();
}

For this you actually need to use my classes fixing this issue - they are available to download here.

this is a copy from my old blogspot blog