Java – duplicate classes when weaving dependencies using maven AspectJ

We are using maven AspectJ plug - in to build our web application It uses "weave dependencies" to add aspects to some dependent jar files

Now we finally have two versions of classes in the Web Application Archive, one in WEB-INF / classes and the other in the original jar file in WEB-INF / lib It seems that only one of the classes has these aspects

I'm afraid it will cause problems

What is the best way to solve this problem?

Discussed the same problem (no solution) over at the eclipse forums

The whole POM XML itself is huge, and of course the included subprojects have their own I hope the excerpts below the war project are rich enough

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <version>2.1.1</version>
    <configuration>
        <filteringDeploymentDescriptors>true</filteringDeploymentDescriptors>
        <filters>
            <filter>${basedir}/src/etc/${environment}/environment.properties</filter>
        </filters>
    </configuration>
</plugin>
<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>aspectj-maven-plugin</artifactId>
    <version>1.2</version> <!-- NB: do use 1.3 or 1.3.x due to MASPECTJ-90 - wait for 1.4 -->
    <dependencies>
        <!-- NB: You must use Maven 2.0.9 or above or these are ignored (see 
            MNG-2972) -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>${aspectj.version}</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjtools</artifactId>
            <version>${aspectj.version}</version>
        </dependency>
    </dependencies>
    <executions>
        <execution>
            <goals>
                <goal>compile</goal>
                <goal>test-compile</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <outxml>true</outxml>
        <aspectLibraries>
            <aspectLibrary>
                <groupId>org.springframework</groupId>
                <artifactId>spring-aspects</artifactId>
            </aspectLibrary>
        </aspectLibraries>
        <weaveDependencies>
            <weaveDependency>
                <groupId>OURPROJECT</groupId>
                <artifactId>OURPROJECT-api</artifactId>
            </weaveDependency>
            <weaveDependency>
                <groupId>OURPROJECT</groupId>
                <artifactId>OURPROJECT-service</artifactId>
            </weaveDependency>
        </weaveDependencies>
        <source>1.6</source>
        <target>1.6</target>
    </configuration>
</plugin>

Solution

Inside the servlet container and war, classes in WEB-INF / classes always take precedence over classes with exactly the same name found in jars in WEB-INF / lib

This is a reference to the servlet spec:

At least since servlet 2.4 This allows the application to selectively patch only a few library classes without repackaging the jar manually or through the Maven plug-in

In your case, you can be sure to always use classes with aspects because they are in WEB-INF / classes and take precedence over classes in WEB-INF / lib