Question

I’m pretty much a total beginner to Spring so don’t assume that just because I didn’t mention something I probably did it anyway.

I’m trying to get dependency injection to work, I got a spring.xml with the following content:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.1.xsd">

<context:annotation-config/>
<bean id="connection" class="richo.project.ConnectionImpl"/>
</beans>

and then in my code I have:

private IConnection conn;
@Resource(name="connection")
public void setConn(IConnection conn){
this.conn = conn;
}

and when I try to use the conn-object in my code I get a nullpointerexception

Bear in mind that I don’t actually know if spring is running, I’m using IntelliJ and it placed 13 spring related jar-files in my lib directory, but I can’t really tell if Spring is even trying to inject anything

Answer 1

Just having Spring in your classpath is not enough to make this work.

You must ask Spring to produce the object you need for any annotations to be honoured. Either this happens in a Spring container, but for stand-alone applications you need to have a Spring context (e.g. AnnotationConfigApplicationContext) and ask it through its getBean() method.