Spring profile XML bean configuration required to be at beginning of file - spring

Question

Using the below Spring configuration I load com.Test2 when DEV profile is used and load com.Test1 when in all other cases:
<beans xmlns="http://www.springframework.org/schema/beans"
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-3.1.xsd">
<bean id="bean1"
class="com.Test1">
</bean>
<beans profile="DEV">
<bean id="bean1"
class="com.Test2">
</bean>
</beans>
</beans>
Moving the Spring profile configuration to the beginning of the file:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
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-3.1.xsd">
<beans profile="DEV">
<bean id="bean1"
class="com.Test1">
</bean>
</beans>
<bean id="bean1"
class="com.Test2">
</bean>
</beans>
the IntelliJ IDE reports the error:
Invalid content was found starting with element '{"http://www.springframework.org/schema/beans":bean}'. One of '{"http://www.springframework.org/schema/beans":beans}' is expected.
Why is this error reported ? Why is it required that the Spring profile be set at the beginning of the file ?

Answer 1

The error is reported because, according to the XML schema, in the second case the elements are in the incorrect order:
As you can see, any <bean> declaration must be provided before any nested <beans>.
This restriction is also indicated in the Spring documentation:
It is also possible to avoid that split and nest <beans/> elements within the same file, as the following example shows:
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:jee="http://www.springframework.org/schema/jee"
xsi:schemaLocation="...">
<!-- other bean definitions -->
<beans profile="development">
<jdbc:embedded-database id="dataSource">
<jdbc:script location="classpath:com/bank/config/sql/schema.sql"/>
<jdbc:script location="classpath:com/bank/config/sql/test-data.sql"/>
</jdbc:embedded-database>
</beans>
<beans profile="production">
<jee:jndi-lookup id="dataSource" jndi-name="java:comp/env/jdbc/datasource"/>
</beans>
</beans>
The spring-bean.xsd has been constrained to allow such elements only as the last ones in the file. This should help provide flexibility without incurring clutter in the XML files.