How to overwrite files in the WAR file during maven build?

Question

I have a Java webapp project that I develop in Eclipse (more precisely MyEclipse 10) and build using Maven 3.

I have the following layout (including only the files relevant to my problem :

project root
|-- src
|   |-- main
|   |   |-- java
|   |   |-- resources
|   |   |   |-- log4j.xml
|   |   |   +-- struts.properties
|   |   |-- webapp
|   |   |   |-- META-INF
|   |   |   |   +--context.xml
|   |   |-- config
|   |   |   |-- test
|   |   |   |   |--log4j.xml
|   |   |   |   |--struts.properties
|   |   |   |   +--context.xml
|   |   |   +-- prod
|   |   |   |   |--log4j.xml
|   |   |   |   |--struts.properties
|   |   |   |   +--context.xml
|   +--test
+--pom.xml

As you can see, I included a number of configuration files. The one who are at their proper location within the project struture, i.e. inside src/main/resources and src/main/webapp are the ones that I routinely use when I work in MyEclipse. I can use MyEclipse connectors to automatically update a deployment to e.g. a Tomcat instance on my dev machine. I just click "run server" and I can debug. No need to use Maven at all in this context actually.

Then, when I want to build a release for another environment such as testing or production, I run mvn -P test clean install and it builds a nice WAR.

My goal is to replace the configuration files inside the final WAR by those in src/config/{environment}/.

I have set profiles in my pom.xml:

<profiles>
    <profile>
        <id>test</id>
        <properties>
            <environment>test</environment>
        </properties>
    </profile>

    <profile>
        <id>prod</id>
        <properties>
            <environment>prod</environment>
        </properties>
    </profile>
</profiles>

Then, I try to copy these resources from the specified profile (using the environment variable) to the correct location inside the WAR (or the temporary folder that will be zipped into a WAR) :

<webResources>
    <resource>
        <directory>/src/main/config/${environment}</directory>
        <targetPath>META-INF/</targetPath>
        <includes>
            <include>context.xml</include>
        </includes>
    </resource>
    <resource>
        <directory>src/main/config/${environment}</directory>
        <targetPath>WEB-INF/classes/</targetPath>
        <includes>
            <include>
                struts.properties
            </include>
            <include>
                log4j.xml
            </include>
        </includes>
    </resource>
</webResources>

Now this seems to work, except that the "standard" resources are copied to the directory AFTER this, so they overwrite these files. So I always end up with e.g. the log4j.xml from src/main/resources instead of the one from say src/main/configuration/prod/

Extract from the Maven output :

[INFO] Processing war project
[INFO] Copying webapp webResources [D:\workspace\MyProject/src/main/config/prod] to [D:\workspaces\SITEL\Webfauna\target\Webfauna]
[INFO] Copying webapp webResources [D:\workspace\MyProject\src/main/config/prod] to [D:\workspaces\SITEL\Webfauna\target\Webfauna]
[INFO] Copying webapp resources [D:\workspace\MyProject\src\main\webapp]

As you can see on the last line, stuff from src/main/webapp is copied AFTER, thus overwriting my custom files :(

My question : How to force Maven to use the files "from the activated profile" and somehow OVERWRITE the "natural" files ?

Answer 1

As pointed in the second Q/A given by user944849, the simplest solution was to filter out the original files so that they can be replaced by the files from the profile's folder.

So I have added filtering to standard resources :

    <resources>
        <resource>
            <directory>src/main/resources</directory>
            <excludes>
                <!-- Exclude those since they are copied from the profile folder for the build -->
                <exclude>log4j.xml</exclude>
                <exclude>struts.properties</exclude>
            </excludes>
            <filtering>false</filtering>
        </resource>
    </resources>

And to the web resources :

<warSourceExcludes>**/context.xml</warSourceExcludes>

So now the 3 files are not copied into the WAR folder. In the next step (webResources) they are copied from the active profile's folder.

I also added a default folder containing the 3 files with common values. The files from this default folder are also copied, but only after the profile's folder ones. As the resources are not overwritten, they will be copied only if they don't already exist. This is useful if you build without a profile activated, or if you can define sensible default values, no each profile needs to replicate the file if it is identical.

Structure of the config folder:

-- config
   |-- test
   |   |--log4j.xml
   |   |   |--struts.properties
   |   |   +--context.xml
   |   +-- prod
   |   |   |--log4j.xml
   |   |   +--context.xml
   |   +-- default
   |       |--log4j.xml
   |       |--struts.properties
   |       +--context.xml
...

And the webResources section of my pom.xml:

<webResources>
    <!-- Resources from the activated profile folder -->
    <resource>
        <directory>/src/main/config/${environment}</directory>
        <targetPath>META-INF/</targetPath>
        <includes>
            <include>context.xml</include>
        </includes>
    </resource>
    <resource>
        <directory>src/main/config/${environment}</directory>
        <targetPath>WEB-INF/classes/</targetPath>
        <includes>
            <include>
                struts.properties
            </include>
            <include>
                log4j.xml
            </include>
        </includes>
    </resource>
    <!-- Default resources in case some file was not defined in the profile folder -->
    <!-- Files are not overwritten so default files will be copied only if it does not exist already -->
    <resource>
        <directory>/src/main/config/default</directory>
        <targetPath>META-INF/</targetPath>
        <includes>
            <include>context.xml</include>
        </includes>
    </resource>
    <resource>
        <directory>src/main/config/default</directory>
        <targetPath>WEB-INF/classes/</targetPath>
        <includes>
            <include>
                struts.properties
            </include>
            <include>
                log4j.xml
            </include>
        </includes>
    </resource> 
</webResources>

Answer 2

Take a look at either of these questions/answers. One may work for you.

Run an ant task in maven build phase before war is packaged?

Files got overwritten in maven project when building a war