Maven JaCoCo Coverage Profile

pom.xml

    <profiles>
        <profile>
            <id>normal</id>
            <activation>
                <activeByDefault>true</activeByDefault>
            </activation>
            <properties>
                <surefireArgLine></surefireArgLine> <!--create blank property for surefire when not running under coverage profile-->
                <failsafeArgLine></failsafeArgLine> <!--create blank property for failsafe when not running under coverage profile-->
            </properties>
        </profile>
        <profile>
            <id>coverage</id>
            <properties>
                <sonar.java.coveragePlugin>jacoco</sonar.java.coveragePlugin>
                <sonar.jacoco.reportPath>${project.build.directory}/jacoco.exec</sonar.jacoco.reportPath>
                <sonar.jacoco.itReportPath>${project.build.directory}/jacoco-it.exec</sonar.jacoco.itReportPath>
            </properties>
            <build>
                <plugins>
                    <plugin>
                        <groupId>org.jacoco</groupId>
                        <artifactId>jacoco-maven-plugin</artifactId>
                        <version>0.7.1.201405082137</version>
                        <executions>
                            <!--
                            Prepares the property pointing to the JaCoCo runtime agent which
                            is passed as VM argument when Maven the Surefire plugin is executed.
                            -->
                            <execution>
                                <id>pre-unit-test</id>
                                <goals>
                                    <goal>prepare-agent</goal>
                                </goals>
                                <configuration>
                                    <!-- Sets the path to the file which contains the execution data. -->
                                    <destFile>${sonar.jacoco.reportPath}</destFile>
                                    <!--
                                    Sets the name of the property containing the settings
                                    for JaCoCo runtime agent.
                                    -->
                                    <propertyName>surefireArgLine</propertyName>
                                </configuration>
                            </execution>
                            <!--
                            Ensures that the code coverage report for unit tests is created after
                            unit tests have been run.
                            -->
                            <execution>
                                <id>post-unit-test</id>
                                <phase>test</phase>
                                <goals>
                                    <goal>report</goal>
                                </goals>
                                <configuration>
                                    <!-- Sets the path to the file which contains the execution data. -->
                                    <dataFile>${sonar.jacoco.reportPath}</dataFile>
                                    <!-- Sets the output directory for the code coverage report. -->
                                    <outputDirectory>${project.reporting.outputDirectory}/jacoco</outputDirectory>
                                </configuration>
                            </execution>
                            <!-- The Executions required by unit tests are omitted. -->
                            <!--
                            Prepares the property pointing to the JaCoCo runtime agent which
                            is passed as VM argument when failsafe plugin is executed.
                            -->
                            <execution>
                                <id>pre-integration-test</id>
                                <phase>pre-integration-test</phase>
                                <goals>
                                    <goal>prepare-agent</goal>
                                </goals>
                                <configuration>
                                    <!-- Sets the path to the file which contains the execution data. -->
                                    <destFile>${sonar.jacoco.itReportPath}</destFile>
                                    <!--
                                    Sets the name of the property containing the settings
                                    for JaCoCo runtime agent.
                                    -->
                                    <propertyName>failsafeArgLine</propertyName>
                                </configuration>
                            </execution>
                            <!--
                            Ensures that the code coverage report for integration tests after
                            integration tests have been run.
                            -->
                            <execution>
                                <id>post-integration-test</id>
                                <phase>post-integration-test</phase>
                                <goals>
                                    <goal>report</goal>
                                </goals>
                                <configuration>
                                    <!-- Sets the path to the file which contains the execution data. -->
                                    <dataFile>${sonar.jacoco.itReportPath}</dataFile>
                                    <!-- Sets the output directory for the code coverage report. -->
                                    <outputDirectory>${project.reporting.outputDirectory}/jacoco-it</outputDirectory>
                                </configuration>
                            </execution>
                        </executions>
                    </plugin>
                </plugins>
            </build>
        </profile>
    </profiles>

Thanks for sharing this config. I'm activating the profile with -Pcoverage yet jacoco never seems to be used, surefire execs without the jacoco agent. Is there something else that needs to be done to activate this?

you need to add ${surefireArgLine} to surfire plugin argLine like:
@{surefireArgLine} -Xms512m -Xmx2048m

You also need to add ${failsafeArgLine} in failsafe plugin like:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-failsafe-plugin</artifactId>
    <version>2.18.1</version>
    <executions>
        <!-- Ensures that both integration-test and verify goals of the Failsafe Maven plugin are executed. -->
        <execution>
            <id>integration-tests</id>
            <goals>
                <goal>integration-test</goal>
                <goal>verify</goal>
             </goals>
             <configuration>
                 <!-- Sets the VM argument line used when integration tests are run. -->
                 <argLine>${failsafeArgLine}</argLine>
             </configuration>
        </execution>
    </executions>
</plugin>