How can I add war file to another java web application dependencies?

Question

I have web maven project. Project's output is a war file. I want to add this war file as dependency to project_b.
The project_b's pom.xml file, have a plugin as following:

...
<plugin>
    <inherited>true</inherited>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <version>2.3</version>
    <configuration>
        <warName>geoserver</warName>
        <webappDirectory>${project.build.directory}/geoserver</webappDirectory>
        <packagingExcludes>WEB-INF/lib/servlet-api*.jar</packagingExcludes>
        <archive>
            <manifest>
                <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
                <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
            </manifest>
            <manifestEntries>
                <GeoServerModule>core</GeoServerModule>
                <Application-Name>${project.build.finalname}</Application-Name>
                <Project-Version>${project.version}</Project-Version>
                <Iteration-Name>${iteration}</Iteration-Name>
                <Build-Timestamp>${maven.build.timestamp}</Build-Timestamp>
                <Git-Revision>${build.commit.id}</Git-Revision>
            </manifestEntries>
        </archive>
    </configuration>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>war</goal>
            </goals>
        </execution>
    </executions>
</plugin>
...

How do I add the war of web application to project_b with <groupId>org.itsme</groupId>, <artifactId>spring3-mvc-maven-xml-hello-world</artifactId>, <packaging>war</packaging> and <version>1.0-SNAPSHOT</version>?

Answer 1

In Maven, adding dependency is just a piece of cake. Take a look on the following pom.xml.

<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/maven-v4_0_0.xsd"
>
    <modelVersion>4.0.0</modelVersion>

    <!-- Project Details -->
    <groupId>ykyuen</groupId>
    <artifactId>project-apple</artifactId>
    <packaging>jar</packaging>
    <version>1.0</version>
    <name>project-apple</name>

    <dependencies>
        <!-- project-apple depends on project-banana -->
        <dependency>
            <groupId>ykyuen</groupId>
            <artifactId>project-banana</artifactId>
            <version>1.0</version>
        </dependency>
    </dependencies>
</project>

Setting the above dependency is just the same as importing the project-banana.jar in project-apple.

Now i have another Maven web application project called project-orange with packaging type equals to war. Adding the above dependency linkage does not work at all since Java does not see .war file as a classpath.

To solve the problem, there are two approaches:

1. Create a Maven module which contains the classes of project-orange with jar packaging. Now you can treat the new Maven module as normal dependency.

2. Configure the maven-war-plugin such that it will build the .jar file when building the .war file. Add the following code under the node of your war project. The following is an example.

.

...
<build>
    <plugins>
        <plugin>
            <artifactId>maven-war-plugin</artifactId>
            <version>2.1.1</version>
            <configuration>
                <attachClasses>true</attachClasses>
                <classesClassifier>classes</classesClassifier>
            </configuration>
        </plugin>
    </plugins>
</build>
...

After running mvn install, you can find the following archive files in the target folder

• project-orange.war
• project-orange-classes.jar

Now you can edit the pom.xml of project-apple for adding the new dependency.

<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/maven-v4_0_0.xsd"
>
    <modelVersion>4.0.0</modelVersion>

    <!-- Project Details -->
    <groupId>ykyuen</groupId>
    <artifactId>project-apple</artifactId>
    <packaging>jar</packaging>
    <version>1.0</version>
    <name>project-apple</name>

    <dependencies>
        <!-- project-apple depends on project-banana -->
        <dependency>
            <groupId>ykyuen</groupId>
            <artifactId>project-banana</artifactId>
            <version>1.0</version>
        </dependency>
        <!-- project-apple depends on project-orange -->
        <dependency>
            <groupId>ykyuen</groupId>
            <artifactId>project-orange</artifactId>
            <version>1.0</version>
            <!-- To map the project-orange-classes.jar -->
            <classifier>classes</classifier>
        </dependency>
    </dependencies>
</project>

reference: http://eureka.ykyuen.info/2009/10/30/maven-dependency-on-jarwar-package/