Problem with Domain Objects DI

[zollen]

I have been experimenting with domain objects dependency-injection(DI) but without much success. I am using the latest spring 3.0.0. Here are the codes:

Account.java

package com.simple.busobj;
@Component
public class Account
{
	private String lastName = null;
	private String firstName = null;
	private int age = 0;
	private String position = null;
	private String level = null;

	public Account (String lastName, String firstName, int age,
			String position, String level) 
	{
		this.lastName = lastName;
		this.firstName = firstName;
		this.age = age;
		this.position = position;
		this.level = level;
	}
}

Teller.java

package com.simple.busobj;
@Configurable(dependencyCheck=true)
public class Teller
{
	@Autowired
	private AccountService accountService;

	public Teller()
	{
	}

	public void debit(Account account, Double amount)
	{
		accountService.debit(account, amount);
	}

	public void deposit(Account account, Double amount)
	{
		accountService.deposit(account, amount);
	}
}

AccountService.java

package com.simple.service;
@Service
public class AccountService
{
	private static Log log = LogFactory.getLog(AccountService.class);


	public AccountService()
	{
	}

	public void debit(Account account, Double amount)
	{
	 log.info("Debiting Account: [" + account + 
               "] with Amount: [" + amount + "]");		
	}

	public void deposit(Account account, Double amount)
	{
		log.info("Depositing Account: [" + account + 
                 "] with Amount: [" + amount + "]");
	}
}

Main.java

public class Main
{
	public static void main (String [] args) throws Exception
	{
	     ApplicationContext ctx = new 
               ClassPathXmlApplicationContext("classpath:simple-di.xml");

		Account account = new Account("Smith", "John", 50, "Manager", "Senior");


		// expected dependency injection (DI) 
		// AccountService object into
		// the teller object, but didn't happen
		Teller teller = new Teller();

		teller.debit(account, new Double(50.99));
	}
}

simple-di.xml

<?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"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd">

	<bean id="accountService" class="com.fundserv.simple.service.AccountService" scope="prototype"/>

	<context:spring-configured/>

</beans>

Here is the runtime error (NullPointerException)

run:
[java] [2010-02-03 21:43:40,297][support.ClassPathXmlApplicationContext][INFO ] Refreshing org.springframework.context.support.ClassPathXmlAp plicationContext@1df38fd: startup date [Wed Feb 03 21:43:40 EST 2010]; root of context hierarchy
[java] [2010-02-03 21:43:40,368][xml.XmlBeanDefinitionReader][INFO ] Loading XML bean definitions from class path resource [simple-di.xml]
[java] [2010-02-03 21:43:40,560][support.DefaultListableBeanFactory][INFO ] Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultL istableBeanFactory@56f631: defining beans [accountService,org.springframework.context.config. internalBeanConfigurerAspect]; root of factory hierarchy
[java] Exception in thread "main" java.lang.NullPointerException
[java] at com.fundserv.simple.busobj.Teller.debit(Teller.jav a:22)
[java] at Main.main(Main.java:21)
[java] Java Result: 1

BUILD SUCCESSFUL
Total time: 0 seconds

[bdangubic]

did you specify com.simple.busobj.Teller in your aop.xml file?

[zollen]

did you specify com.simple.busobj.Teller in your aop.xml file?

Why? Teller is just a pojo. It is not an advice at all.

[bdangubic]

Why? Teller is just a pojo. It is not an advice at all.

it's all in the documentation...

http://static.springsource.org/sprin...tw-aop_dot_xml

[zollen]

Above suggestions work as expected. However when I replace the following:

ClassPathXmlApplicationContext("classpath:simple-di.xml");

*with*

AnnotationConfigApplicationContext(SimpleConfig.cl ass);

Domain injection no longer works.

Here are the codes:
Account.java (same as above)
AccountService.java (same as above)

Main.java

public class Main
{
        public static void main (String [] args) throws Exception
        {
               ApplicationContext ctx = new AnnotationConfigApplicationContext(SimpleConfig.class);

                Account account = new Account("Smith", "John", 50, "Manager", "Senior");

                // expected dependency injection (DI) 
                // AccountService object into
                // the teller object, but didn't happen
                Teller teller = new Teller();

                teller.debit(account, new Double(50.99));
         }
}

SimpleConfig.java

@Configuration
@ImportResource({"classpath:simple-di.xml"})
public class SimpleConfig 
{ }

Teller.java

@Configurable(dependencyCheck=true)
public class Teller
{
        @Autowired
        private AccountService accountService;

        public void debit(Account account, Double amount)
        {
                accountService.debit(account, amount);
        }

        public void setAccountService(AccountService service)
        {
                this.accountService = service;
        }
}

simple-di.xml

<?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"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
	http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd">

	<bean id="accountService" class="com.simple.service.AccountService" scope="prototype">
		<aop:scoped-proxy />
	</bean>

	<bean class="com.simple.busobj.Teller">
		<property name="accountService" ref="accountService"/>
	</bean>

	<context:load-time-weaver />

</beans>

This is the successful output when using ClassPathXmlApplicationContext("classpath:simple-di.xml");

run:
[java] [2010-02-08 22:36:38,881][support.ClassPathXmlApplicationContext][INFO ] Refreshing org.springframework.context.support.ClassPathXmlAp plicationContext@27391d: startup date [Mon Feb 08 22:36:38 EST 2010]; root of context hierarchy
[java] [2010-02-08 22:36:38,968][xml.XmlBeanDefinitionReader][INFO ] Loading XML bean definitions from class path resource [simple-di.xml]
[java] [2010-02-08 22:36:39,220][weaving.DefaultContextLoadTimeWeaver][INFO ] Found Spring's JVM agent for instrumentation
[java] [2010-02-08 22:36:39,659][support.DefaultListableBeanFactory][INFO ] Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultL istableBeanFactory@1e2ca7: defining beans [scopedTarget.accountService,accountService,com.fun dserv.simple.busobj.Teller#0,org.springframework.c ontext.weaving.AspectJWeavingEnabler#0,org.springf ramework.context.config.internalBeanConfigurerAspe ct,loadTimeWeaver]; root of factory hierarchy
[java] [2010-02-08 22:36:40,615][service.AccountService][INFO ] Debiting Account: [FirstName: [John] LastName: [Smith] Age: [50] Position: [Manager] Level: [Senior]] with Amount: [50.99]

This is the failure when using AnnotationConfigApplicationContext(SimpleConfig.cl ass);

run:
[java] [2010-02-08 22:39:10,724][annotation.AnnotationConfigApplicationContext][INFO ] Refreshing org.springframework.context.annotation.AnnotationC onfigApplicationContext@126e85f: startup date [Mon Feb 08 22:39:10 EST 2010]; root of context hierarchy
[java] [2010-02-08 22:39:10,835][xml.XmlBeanDefinitionReader][INFO ] Loading XML bean definitions from class path resource [simple-di.xml]
[java] [2010-02-08 22:39:11,129][annotation.ConfigurationClassEnhancer][INFO ] Successfully enhanced com.fundserv.simple.config.SimpleConfig; enhanced class name is: com.fundserv.simple.config.SimpleConfig$$EnhancerB yCGLIB$$59478e5f
[java] [2010-02-08 22:39:11,151][support.DefaultListableBeanFactory][INFO ] Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultL istableBeanFactory@30d082: defining beans [org.springframework.context.annotation.internalCon figurationAnnotationProcessor,org.springframework. context.annotation.internalAutowiredAnnotationProc essor,org.springframework.context.annotation.inter nalRequiredAnnotationProcessor,org.springframework .context.annotation.internalCommonAnnotationProces sor,simpleConfig,scopedTarget.accountService,accou ntService,com.fundserv.simple.busobj.Teller#0,org. springframework.context.weaving.AspectJWeavingEnab ler#0,org.springframework.context.config.internalB eanConfigurerAspect,loadTimeWeaver]; root of factory hierarchy
[java] [2010-02-08 22:39:11,310][weaving.DefaultContextLoadTimeWeaver][INFO ] Found Spring's JVM agent for instrumentation
[java] Exception in thread "main" java.lang.NullPointerException
[java] at com.fundserv.simple.busobj.Teller.debit(Teller.jav a:22)
[java] at Main.main(Main.java:26)
[java] Java Result: 1

[zollen]

My initial conclusion:

There is a bug in AnnotationConfigApplicationContext(SimpleConfig.cl ass), that could stop LTW from working properly.

[Chris Beams]

Try the latest snapshot build of Spring. The lifecycle of @Configuration class processing has been improved recently with SPR-6611. I cannot guarantee that this change will provide the fix, but would very much appreciate your report as to whether it does.

Also feel free to enter a JIRA issue for this and please attach a minimal test case that reproduces the problem. I'll be happy to look into it.

[Chris Beams]

Of course, now you can simply use the just-released Spring 3.0.1.

[zollen]

Thanks. I will retest the issue.

[zollen]

Yep. I just re-test the Java Config class loaded with multiple spring beans XML files, and one of the bean XML file defines <context:load-time-weaver />. The latest 3.0.1-A release seem to have fixed the bug when <context:load-time-weaver /> tag is used in conjunction with Java Config class. My Domain objects dependency injection is working now.

Thanks!