Is there a way to execute a program in maven to help build your project?

Question

I am currently working on a project that uses a tool that takes the following example IDL file and generates about 5 Java classes from it.

struct Example { int x; int y; };

Is there a way to get Maven to use the command line tool that we use to automatically create those Java classes when it builds?

Answer 1

Here is an example using the Exec Maven Plugin.

<plugins>
    <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>exec-maven-plugin</artifactId>
        <version>1.2.1</version>
        <executions>
            <execution>
                <!-- this execution happens just after compiling the java classes, and builds the native code. -->
                <id>build-native</id>
                <phase>process-classes</phase>
                <goals>
                    <goal>exec</goal>
                </goals>
                <configuration>
                    <executable>src/main/c/Makefile</executable>
                    <workingDirectory>src/main/c</workingDirectory>
                </configuration>
            </execution>
        </executions>
    </plugin>
</plugins>

Answer 2

You can use maven-antrun-plugin plugin to run arbitrary Ant tasks or even any command-line program:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-antrun-plugin</artifactId>
            <version>3.0.0</version>
            <executions>
                <execution>
                    <phase>generate-sources</phase>
                    <configuration>
                        <target>
                            <exec executable="ls">
                                <arg value="-l"/>
                                <arg value="-a"/>
                            </exec>
                        </target>
                    </configuration>
                    <goals>
                        <goal>run</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

With this configuration your command-line program will be executed before the compilation, so generated Java sources will be available to the rest of the code.