Solving java.io.FileNotFoundException in Spring and iBATIS

I'm happily hacking about with iBATIS Spring DAO classes. I exposed the DAO classes using RPC services with GWT and the GWT server library and I run these RPC services in Tomcat. I also wanted to have unit tests that test my DAO classes, and there is this wonderful thing called gienah-testing on Google code, that allowed me to use Spring to inject the DAO classes into my unit test classes.

Now at this stage I started to get a FileNotFoundException on either my Spring configuration files or my SqlMapConfig.xml. When I referred to the configuration files using the scheme "/com/acme/config.xml", this caused loading the SqlMapConfig configuration to fail when running in Tomcat. I could solve the problem in Tomcat by referring to "WEB-INF/classes/com/acme/config.xml", but this caused my gienah-testing unit test classes to fail with a FileNotFoundException on the Spring configuration.

To solve this problem, I had to make sure that everything was loaded from the classpath using the ClassPathXmlApplicationContext. This is very simple, just prefix the location of the configuration file with "classpath:" without the quotes, e.g. "classpath:/com/acme/config.xml". This way both the gienah-test unit tests will load the configuration from the classpath using the classloader (e.g. in /classes if that were to be your output folder in Eclipse) and the web container will also load the configuration from the classpath using the classloader (in this case WEB-INF/classes). Here is a snippet of the gienah-testing test class, where data.xml is the configuration file containing the iBATIS Spring DAO configuration:

@RunWith(value = SpringRunner.class)
@Configuration(locations = {"classpath:/com/acme/data/data.xml", 
"classpath:/com/acme/test/test.xml"})
public class AcmeTest {

All other configuration files also refer to any underlying configuration files using the "classpath:" prefix, again in order to make sure that the ClassPathXmlApplicationContext is used. This is a snippet from the web.xml, injecting data.xml into the application context configuration file location:

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:/com/acme/data/data.xml</param-value>
</context-param>

The data.xml containing the iBATIS Spring DAO configuration injects the SqlMapConfig.xml, also with the "classpath:" prefix, as shown in the snippet below:

<bean id="sqlMapClient" class="org.springframework.orm.ibatis.SqlMapClientFactoryBean">
    <property name="dataSource" ref="myDataSource" />
    <property name="configLocation" value="classpath:/com/acme/data/SqlMapConfig.xml" />
</bean>

This should solve any FileNotFoundException problems in both the gienah-testing unit tests and when running in Tomcat. It works like a charm for me :-)