Autowiring DataSource NullPointerException

Question

 public class DAOManager {
      @Autowired
      private DataSource dataSource;
 .....

When I go to run the above, dataSource remains as null.

How I've configured the bean in web-context.xml:

<!-- Datasource (database) bean -->
<bean id="dataSource"
     class="org.springframework.jdbc.datasource.DriverManagerDataSource">
     <property name="driverClassName" value="com.mysql.jdbc.Driver" />
     <property name="url" value="XXXXX" />
     <property name="username" value="XXXX" />
     <property name="password" value="XXXX" />
</bean>

I feel like there's something I need to be adding to my web-context.xml to add the DAOManager class into its jurisdiction.. am I right with this? Sorry, first time Spring MVC user.

Thank you for your time.

Do you have a bean definition for `DAOManager`? Spring has to instantate it as well in order to apply autowiring. — Jim Garrison, Dec 02 '13 at 17:20
@JimGarrison - I do not, no. I'm not really sure where to do this, either. — Samuel Smith, Dec 02 '13 at 17:28
Let me know if neither the injection or `@Configurable` approaches I describe in my writeup looks like it'll work. Usually, reorganizing the code a bit so that everything's injected is the best long-term approach, but DAO is one common pattern where `@Configurable` is really useful (though usually with Active Record; a full `DAOManager`-type class is usually injected). — chrylis -cautiouslyoptimistic-, Dec 02 '13 at 17:29
@chrylis - I'm reading through it all now, there's a lot to read/get my head around. I'll get back to you in a bit. — Samuel Smith, Dec 02 '13 at 17:36
Are you running this in a container such as Tomcat or JBoss? If not you will need to have a top-level Spring-aware class to initiate the whole wiring process. — Jim Garrison, Dec 02 '13 at 17:50
Yeah, there's a good bit going on under the hood in Spring. It's powerful, but there are a few gotchas with all the moving parts. Short version is that unless you use AspectJ, Spring doesn't know about anything you call `new` on. — chrylis -cautiouslyoptimistic-, Dec 02 '13 at 17:59

score 0 · Answer 1 · answered Dec 02 '13 at 17:27

0

You ask:

I feel like there's something I need to be adding to my web-context.xml to add the DAOManager class into its jurisdiction.. am I right with this?

You are right :)

answered Dec 02 '13 at 17:27

Michael Wiles

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score 0 · Answer 2 · answered Dec 02 '13 at 17:44

0

Put @Repository above your class DAOManager and see.

Though idealy the configuration you did, seems fine, and is a simple DI, and should work fine as it is now.

answered Dec 02 '13 at 17:44

Abhishek Anand

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score 0 · Answer 3 · answered Dec 02 '13 at 17:45

0

Just add

<bean id="daoManager" class="DAOManager">
        <property name="dataSource" ref="dataSource" />
</bean>

answered Dec 02 '13 at 17:45

Jérôme Gloaguen

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score -1 · Answer 4 · answered Dec 02 '13 at 17:28

-1

Add to your spring xml

<context:component-scan base-package="com.your.package" />

answered Dec 02 '13 at 17:28

andi

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This won't make any difference, since the `DAOManager` isn't any sort of Spring bean. – chrylis -cautiouslyoptimistic- Dec 02 '13 at 17:31
<- Added this, and no difference. – Samuel Smith Dec 02 '13 at 17:34
I assume that you can't annotate DAOManager? – andi Dec 02 '13 at 17:39

Autowiring DataSource NullPointerException

4 Answers4