How to add one more dtd to my Spring configration file?

Question

I have use a .dtd to my applicationContext.xml, but now i want to use Spring's AOP based on annotation. I've been told to add a in my applicationContext.xml.

<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <aop:aspectj-autoproxy />
...

But something wrong happens. It seems that the file doesn't recognize the aop node, so i think i should import one more .dtd file, and i find this:

<!DOCTYPE aspectj PUBLIC
        "-//AspectJ//DTD//EN" "http://www.eclipse.org/aspectj/dtd/aspectj.dtd">

but can i use both .dtd togeter? how?

thx

score 2 · Accepted Answer · answered Aug 22 '12 at 17:33

You don't have to use DOCTYPE here, better declare xml namespaces like this:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd">

<beans>
    <aop:aspectj-autoproxy />
...

xmlns="http://www.springframework.org/schema/beans" means that beans will be root namespace (you don't have to use <beans:bean>) and aop will be accesible as desired.

score 0 · Answer 2 · answered Aug 23 '12 at 21:39

The two DTDs you cite are not constructed in a way that allows them to be used together. In particular, the definition of beans in http://www.springframework.org/dtd/spring-beans.dtd is just

<!ELEMENT beans (
              description?,
              (import | alias | bean)*
)>

It does not provide for a child named aop:aspectj-autoproxy, and it doesn't provide any mechanism for later users like you to add new things to the content of beans.

DTDs can be built for extensibility and to support the integration of elements from multiple namespaces, though it requires a bit of forethought and planning. When extension points are not included, it's typically pretty hard or impossible to extend the DTD without just rewriting it.

How to add one more dtd to my Spring configration file?

2 Answers2