Adding AspectJ to pom.xml changed Java version with Maven, why?

aspectj, java, maven, pom.xml

Solution

I think the problem is with the default source, target and complianceLevel settings of the aspectj-maven-plugin (according to the documentation linked previously, 1.4, 1.2 and 1.4 respectively). You should set these explicitly in your parent pom:

<build>
    <plugins>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>aspectj-maven-plugin</artifactId>
            <version>1.5</version>
            <!-- new configuration is here -->
            <configuration>
                <complianceLevel>1.6</complianceLevel>
                <source>1.6</source>
                <target>1.6</target>
            </configuration>
            <executions>
                <execution>
                    <goals>
                        <goal>compile</goal>
                        <goal>test-compile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
        ...
    </plugins>
<build>

Problem

UPDATE: here is my maven-compiler-plugin configuration: ``` <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>2.3.2</version> <configuration> <source>1.6</source> <target>1.6</target> </configuration> ``` I work on a multi-project application that I build with Maven. We decided to add AspectJ so I added the following code to `pom.xml` in the top level project: (from the official documentation) ``` <project> ... <dependencies> ... <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjrt</artifactId> <version>1.7.3</version> </dependency> ... </dependencies> ... <build> <plugins> <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>aspectj-maven-plugin</artifactId> <version>1.5</version> <executions> <execution> <goals> <goal>compile</goal>  <goal>test-compile</goal>  </goals> </execution> </executions> </plugin> ... </plugins> <build> ... </project> ``` and the following fragments to each subordinate projects: ``` </project> ... <build> .... <plugins> ... <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>aspectj-maven-plugin</artifactId> </plugin> </plugins> </build> <dependencies> ... <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjrt</artifactId> </dependency> .... </dependencies> ... </project> ``` Somehow this modification has overridden the Java version I use. If I run build I get multiple errors like this: Syntax error, annotations are only available if source level is 1.5 or greater That gives me the suspicion that my Java version (originally 1.6) was somehow reverted to 1.4. I did nothing - at least not knowingly - that could influence the Java version, so I suspect that the above mentioned AspectJ related code is responsible for the change. My question is how can AspectJ change the Java version and what should I do to fix this problem. Or do I misunderstand something completely and am I on the wrong track?

Original source