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 ?

Menses

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>

Menses

Brilliant piece of information. I was searching for the exact solution and got it. Thanks a lot. – Woolworth

Answer 2

I think you need to overlay the war files. Either creating a dependency in every profile of type war instead of jar, that will overlay the files in your current war file.

Another possibility might be the overlay configuration of the maven-war-plugin.

so the profile would activate the files you want to have copied over the current ones. There is quite some documentation on the plugin site as well with some examples

Hope that works!

Eozoic

But my custom config files are not part of an external WAR, so I'm not sure how I could apply them as overlay... not convinced ! – Menses

I think you dont need to use an external war file if you are using the maven-war-plugin and the overlays. The id/artifactId/groupId parameters seem to be optional, so you dont need to put the environment config in a separate module. – Eozoic

the war-plugin seems to run in the package phase: maven.apache.org/guides/introduction/… while the resources plugin runs earlier in process-resources. I dont think that way will work to trick the war-plugin. – Eozoic

Answer 3

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

Atreus

Q2 : Onto something here. I was trying using packagingExcludes but it didn't work. Looks like warSourceExcludes might do the trick. – Menses

Answer 4

another attempt :)

I've played around with the overlay parameter. I think that only replaces files within webapp folder you have in another war file inside the webapp folder. So that is not the perfect thing for your setup.

Yet the above mentioned webResource parameter can do this:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>org.mimacom.maven.examples</groupId>
<artifactId>mimacom-war-overlays</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>war</packaging>

<name>${project.artifactId}</name>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.build.compiler.version>1.6</project.build.compiler.version>
    <junit.version>4.9</junit.version>
</properties>

<build>
    <pluginManagement>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.5.1</version>
                <configuration>
                    <source>${project.build.compiler.version}</source>
                    <target>${project.build.compiler.version}</target>
                    <encoding>${project.build.sourceEncoding}</encoding>
                </configuration>
            </plugin>
        </plugins>
    </pluginManagement>

    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-war-plugin</artifactId>
            <version>2.3</version>
        </plugin>
    </plugins>
</build>

<dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>${junit.version}</version>
    </dependency>
</dependencies>

<profiles>
    <profile>
        <id>prod</id>
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-war-plugin</artifactId>
                    <version>2.3</version>
                    <configuration>
                        <webResources>
                            <resource>
                                <directory>src/main/config/prod</directory>
                            </resource>
                        </webResources>
                        <!--<includes>-->
                            <!--<include>${basedir}/environments/overlay-1/css/styles.css</include>-->
                        <!--</includes>-->
                        <!--<overlays>-->
                            <!--<overlay>-->
                                <!--<includes>-->
                                    <!--../environments/overlay-1/css/**-->
                                <!--</includes>-->
                            <!--</overlay>-->
                        <!--</overlays>-->
                    </configuration>
                </plugin>
            </plugins>
        </build>
    </profile>
    <profile>
        <id>test</id>
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-war-plugin</artifactId>
                    <version>2.3</version>
                    <configuration>
                        <webResources>
                            <resource>
                                <directory>src/main/config/test</directory>
                            </resource>
                        </webResources>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    </profile>

</profiles>

The activated profiles will add additional folders to the war file. So that should do the trick!

Eozoic

Answer 5

I see that you would use the same resources but with different configuration in each profile (test and prod).

So, I suggest you to use a configuration like this:

<profiles>
<profile>
    <id>test</id>
    <activation>
        <activeByDefault>true</activeByDefault>
        <property>
            <name>env</name>
            <name>test</name>
        </property>
    </activation>
    <build>
        <filters>
            <filter>test.properties</filter>
        </filters>
    </build>
</profile>

<profile>
    <id>prod</id>
    <activation>
        <property>
            <name>env</name>
            <value>prod</value>
        </property>
    </activation>
    <build>
        <filters>
            <filter>prod.properties</filter>
        </filters>
    </build>
</profile>
</profiles>

In this scenario, I have two profiles, each one is activated using "env" parameter. Each profile has a file to filter your resources, put your log4j.xml, struts.properties, context.xml files in src/main/resources and use variables to use right configuration in each profile.

Hope that helps.

Embowel

Answer 6

Here is a simpler version of the solutions above that relies only on a simple snippet inserted into pom.xml.

Build the default (local workstation) webapp with:

mvn war:exploded

Add an environment command line parameter to copy files from an environment-specific directory like resources-prod to the target WEB-INF/classes directory:

mvn war:exploded -Denvironment=prod

Add this inside the project element of pom.xml:

<!-- this profile will allow files in environment-specific folders like resources-prod or resources-test
     to be added to the resulting war's classpath under WEB-INF/classes
     to activate the profile, simply add '-Denvironment=prod' to your maven build command 
     this also works fine with war:inplace and war:exploded 
-->
<profile>
    <id>environment-specific</id>
    <activation>
        <property>
            <name>environment</name>
        </property>
    </activation>
    <build>
    <plugins>   
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-war-plugin</artifactId>
        <version>2.4</version>
        <configuration>
            <webResources>
                <!-- note the order of the following resource elements are important. 
                     if there are duplicate files, the first file copied will win
                -->
                <resource>
                    <!-- this is relative to the pom.xml directory -->                        
                    <directory>resources-${environment}</directory>
                    <!-- override default destination at root of war -->
                    <targetPath>WEB-INF/classes</targetPath>
                </resource>
                <resource>
                    <directory>src/main/resources</directory>
                    <targetPath>WEB-INF/classes</targetPath>
                </resource>
            </webResources>
        </configuration>
      </plugin>             
    </plugins>
    </build>
</profile>

More info and link to working example.

Cloison