Integration tests with Maven in a Spring project - spring

Question

The question is how can I use different properties files for integration testing. Detailed explanation follows.
I'm trying to do in container integration tests with Maven, using tomcat7-maven-plugin. The project uses Spring and JPA. At present what I've figured out is the following:
Unit test class names follow the pattern *Test and run with mvn test by maven-surefire-plugin
Integration test class names follow the pattern *IT and run with mvn verify by maven-failsafe-plugin
With executions I can trigger to start and stop tomcat and deploy the war file
All of this works and when I run mvn verify Tomcat is started.
However instead of using a regular database, I would like to use an in memory database. My database configuration is defined in the file src/main/resources/META-INF/spring/database.properties loaded through context:property-placeholder.
I tried to define an alternative file in src/test/resources/META-INF/spring/database.properties, but is ignored. I know that is possible to define system properties within tomcat7-maven-plugin, but I don't know how to use them to trigger loading of different properties files.
My tomcat7-maven-plugin configuration is the following:
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.1</version>
<configuration>
<port>9090</port>
<path>/processing</path>
<useTestClasspath>true</useTestClasspath>
<systemProperties>
<example.value.1>alpha</example.value.1>
</systemProperties>
</configuration>
<executions>
<execution>
<id>start-tomcat</id>
<phase>pre-integration-test</phase>
<goals>
<goal>run-war-only</goal>
</goals>
<configuration>
<fork>true</fork>
</configuration>
</execution>
<execution>
<id>stop-tomcat</id>
<phase>post-integration-test</phase>
<goals>
<goal>shutdown</goal>
</goals>
</execution>
</executions>
</plugin>
Properties are loaded by context-main.xml with the following line:
<context:property-placeholder location="classpath*:META-INF/spring/*.properties"/>
I load context configuration from web.xml with the following:
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath*:META-INF/spring/context-*.xml</param-value>
</context-param>
Any suggestion on how to load alternative properties file for testing?

Answer 1

One way to do it, is with Maven profiles and the ant plugin. I suspect that is not the most elegant way, and I'm open to listen for better solution, but for now it solves my problem.
A profile is a way to have a different Maven configuration depending on command line arguments, so in my case to run the integration tests, I run the command mvn -Pintegration clean verify. Here integration is the name of the profile, and is defined in pom.xml, after the properties as follows:
<profiles>
<profile>
<id>standard</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
</profile>
<profile>
<id>integration</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<version>1.1</version>
<executions>
<execution>
<phase>test</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<tasks>
<echo>Copying test database.properties to ${project.build.outputDirectory}/META-INF/spring/</echo>
<copy file="src/test/resources/META-INF/spring/database.properties"
todir="${project.build.outputDirectory}/META-INF/spring/" verbose="true" overwrite="true" />
</tasks>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
</profiles>
Using mvn clean package will instead use the standard profile. It's interesting to mention that profiles can also be defined outside the pom, in .m2/settings.xml
See also: Building For Different Environments with Maven 2 -- Notice that the overwrite parameter in the copy is essential or it will work only at random, and is not mentioned in the linked document.