If you dependencies are at the same level in the dependency tree, the order of declaration in your pom will win, as per Maven Dependency Mediation doc:
Note that if two dependency versions are at the same depth in the dependency tree, until Maven 2.0.8 it was not defined which one would win, but since Maven 2.0.9 it's the order in the declaration that counts: the first declaration wins
So in your case the two dependencies are at the same level in the dependency tree (first level, declared in the POM) and compile scope would be present whenever test scope would be, as such jar2 would win because you declared it first in your POM (according to the snipped you posted).
If you want the file to be loaded always from jar3 but only during tests, simply declare jar3 first in your dependencies. It will not impact the final deliverable (being in test scope) but it will define the order to the classpath for testing and as such giving you the expected scenario. You don't need Maven profiles for that.
A simple test case to verify it:
Let's define a property file.properties into src\main\resources of a Maven project. The file would look like the following for project resource-provider (artifactId):
property=from-resource-provider
And as following for project resource-provider2 (artifactId):
property=from-resource-provider2
Note: the same file name into two different projects with different content.
Then in a consumer project (resource-consumer) we could have the following sample JUnit test case:
public class MainTest { @Test public void checkClassPath() { InputStream is = MainTest.class.getResourceAsStream("/file.properties"); Scanner s = new Scanner(is); System.out.println(s.nextLine()); } }
For the following dependencies into resource-consumer:
<dependencies> <dependency> <groupId>com.sample</groupId> <artifactId>resource-provider2</artifactId> <version>0.0.1-SNAPSHOT</version> <scope>test</scope> </dependency> <dependency> <groupId>com.sample</groupId> <artifactId>resource-provider</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> </dependencies>
Output of test execution would be:
------------------------------------------------------- T E S T S ------------------------------------------------------- Running com.sample.MainTest property=from-resource-provider2 Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.051 sec
So, the first dependency declared, resource-provider2, won (note the scope, test).
Changing the dependencies order to:
<dependencies> <dependency> <groupId>com.sample</groupId> <artifactId>resource-provider</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> <dependency> <groupId>com.sample</groupId> <artifactId>resource-provider2</artifactId> <version>0.0.1-SNAPSHOT</version> <scope>test</scope> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> </dependencies>
Would instead give the following output:
------------------------------------------------------- T E S T S ------------------------------------------------------- Running com.sample.MainTest property=from-resource-provider Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.07 sec
Note: this time resource-provider won, because it was declared first and because compile scope is also part of test scope, while the contrary is not true.
