How can I write maven build to add resources to classpath?

Question

I am building a jar using maven with simple maven install. If I add a file to src/main/resources it can be found on the classpath but it has a config folder where I want that file to go but moving it inside the config folder makes it disappear from the classpath.

Answer 1

A cleaner alternative of putting your config file into a subfolder of src/main/resources would be to enhance your classpath locations. This is extremely easy to do with Maven.

For instance, place your property file in a new folder src/main/config , and add the following to your pom:

 <build>
    <resources>
        <resource>
            <directory>src/main/config</directory>
        </resource>
    </resources>
 </build>

From now, every files files under src/main/config is considered as part of your classpath (note that you can exclude some of them from the final jar if needed: just add in the build section:

    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <configuration>
                <excludes>
                    <exclude>my-config.properties</exclude>
                </excludes>
            </configuration>
        </plugin>
    </plugins>

so that my-config.properties can be found in your classpath when you run your app from your IDE, but will remain external from your jar in your final distribution).

Answer 2

If you place anything in src/main/resources directory, then by default it will end up in your final *.jar . If you are referencing it from some other project and it cannot be found on a classpath, then you did one of those two mistakes:

1. *.jar is not correctly loaded (maybe typo in the path?)
2. you are not addressing the resource correctly, for instance: /src/main/resources/conf/settings.properties is seen on classpath as classpath:conf/settings.properties

Answer 3

By default maven does not include any files from "src/main/java". 
You have two possible way to that.
  1. put all your resource files (different than java files) to "src/main/resources" - this is highly recommended  
  2. Add to your pom (resource plugin):

 <resources>
       <resource>
           <directory>src/main/resources</directory>
        </resource>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
  </resources>