AspectJ weaving from dependency not applying to project

Question

I have a Java 8 Maven project that defines a custom annotation and an aspect. When running test code in that project itself, it is applying the aspect to the annotated classes. I am then packaging and installing project.

I then bring in that dependency into a new project (non-Spring). The new project is then not having the aspect applied to it's classes, though it does bring in the new annotation.

How do I have a single JAR to define an annotation and aspect and have it applied to all of my projects with Maven?

Do you have compile time weaving enabled in your new project's build process? Or do you have load-time weaving enabled when you run your new project? — Nándor Előd Fekete, May 22 '18 at 14:15
@NándorElődFekete I am trying compile time, the same as the original project containing the aspect itself. That project compiles and executes the aspects fine. I have the same build plugin configured on the project bringing in the aspect as a dependency, but the aspects are not being applied. — FiguringThisOut, May 22 '18 at 14:32
Build configuration is not necessarily trivial, so please add the relevant build configuration to your question. — Nándor Előd Fekete, May 22 '18 at 14:37
@NándorElődFekete Do you know of any examples out there where the aspect used for a build is brought in as a dependency? I feel it is a common use case, I just have been unable to search for either instructions or examples on how to weave an aspect from a dependency. — FiguringThisOut, May 22 '18 at 16:35
Here's an [anwer](https://stackoverflow.com/a/36023217/2699901) I made earlier to an unrelated question, but it could be useful for you because it contains an example on how to specify aspect libraries in a maven build. — Nándor Előd Fekete, May 22 '18 at 16:42
@NándorElődFekete Thank you very much! Configuring aspectLibraries was the answer. If you copy-paste your referenced info here I'll mark it as the answer. Thank you for your help. — FiguringThisOut, May 22 '18 at 18:29

Nándor Előd Fekete · Accepted Answer · 2020-01-29T15:38:20.060

You need to specify your aspect project dependency as an aspect library in your aspectj-maven-plugin configuration in your pom.xml. Let's suppose your aspect module has the groupid:artifactid groupid:aspect-module. Your pom.xml should look similar to this:

<dependencies>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjrt</artifactId>
    </dependency>
    <dependency>
        <groupId>groupid</groupId>
        <artifactId>aspect-module</artifactId>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <executions>
                <execution>
                    <id>default-compile</id>
                    <phase>none</phase>
                </execution>
            </executions>
        </plugin>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>aspectj-maven-plugin</artifactId>
            <version>1.9</version>
            <configuration>
                <aspectLibraries>
                    <aspectLibrary>
                        <groupId>groupid</groupId>
                        <artifactId>aspect-module</artifactId>
                    </aspectLibrary>
                </aspectLibraries>
            </configuration>
            <executions>
                <execution>
                    <goals>
                        <goal>compile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

Note that I'm switching off the maven-compiler-plugin because they tend do overwrite each other's output with the aspectj-maven-plugin, and the AspectJ compiler should be able to compile normal java files and weave them in the same step anyway, so using the maven-compiler-plugin is redundant. If you are using Eclipse + AJDT, this maven configuration will much better reflect what happens in your IDE while you're developing.

AspectJ weaving from dependency not applying to project

1 Answers1