adam bien's blog

How To Reuse Java EE 6 WAR Code With Maven (3) 📎

In Java EE 6 WAR is the new EAR. A WAR, however, is entirely "installed" to the maven 3 repo. It's contents (like JAXB-DTOs), cannot be reused from other applications.
Configuration of maven-jar-plugin and maven-install-plugin solves the issue. The first plugin creates a JAR and the latter installs it into the local repo:


...
<plugins>
<plugin>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-jar-plugin</artifactId>
   <executions>
       <execution>
           <id>make-jar</id>
           <phase>compile</phase>
           <goals>
               <goal>jar</goal>
           </goals>
       </execution>
   </executions>
</plugin>
<plugin>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-install-plugin</artifactId>
   <executions>
       <execution>
           <id>install-jar</id>
           <phase>install</phase>
           <goals>
               <goal>install-file</goal>
           </goals>
           <configuration>
               <packaging>jar</packaging>
               <artifactId>${project.artifactId}</artifactId>
               <groupId>${project.groupId}</groupId>
               <version>${project.version}</version>
               <file>${project.build.directory}/${project.build.finalName}.jar</file>
           </configuration>
       </execution>
   </executions>
</plugin>
...
</plugins>

After configuration of both plugins, WAR contents are redundantly stored as JAR in the local maven repository and are accessible to other projects by specifying a "usual" dependency to it.

You could also use the attachClasses tag to deploy the jar in addition to the WAR with the "classes" classifier (as suggested by struberg):


<plugin>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-war-plugin</artifactId>
   <version>2.1.1</version>
   <configuration>
      <attachClasses>true</attachClasses>

But then you will also have to specify the classifier in the dependency:


<dependency>
    <groupId>...</groupId>
    <artifactId>...</artifactId>
    <version>...</version>
   <classifier>classes</classifier>
    <scope>test</scope>
</dependency>