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

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).

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

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>