title: No JaCoCo analysis of project coverage can be done since there is no class files
body: <p>I am using Bamboo, SonarQube, and Maven plugin for generating the Jacoco Report in SonarQube. It is generating jacoco.exec file but how to display reports in SonarQube? Following plugin i am using 
                 '</p>
  
  <pre><code>&lt;plugin&gt;
                  &lt;groupId&gt;org.jacoco&lt;/groupId&gt;
                  &lt;artifactId&gt;jacoco-maven-plugin&lt;/artifactId&gt;
                  &lt;version&gt;0.7.7.201606060606&lt;/version&gt;
                  &lt;executions&gt;
                      &lt;execution&gt;
                          &lt;id&gt;pre-unit-test&lt;/id&gt;
                          &lt;goals&gt;
                              &lt;goal&gt;prepare-agent&lt;/goal&gt;
                          &lt;/goals&gt;
                          &lt;configuration&gt;
                              &lt;!-- Sets the path to the file which contains the execution data. --&gt;
                              &lt;destFile&gt;${project.build.directory}/jacoco.exec&lt;/destFile&gt;
                              &lt;!-- Sets the name of the property containing the settings for JaCoCo 
                                  runtime agent. --&gt;
                              &lt;propertyName&gt;surefireArgLine&lt;/propertyName&gt;
                          &lt;/configuration&gt;
                      &lt;/execution&gt;
                      &lt;!-- Ensures that the code coverage report for unit tests is created 
                          after unit tests have been run. --&gt;
                      &lt;execution&gt;
                          &lt;id&gt;post-unit-test&lt;/id&gt;
                          &lt;phase&gt;test&lt;/phase&gt;
                          &lt;goals&gt;
                              &lt;goal&gt;report&lt;/goal&gt;
                          &lt;/goals&gt;
                          &lt;configuration&gt;
                              &lt;!-- Sets the path to the file which contains the execution data. --&gt;
                              &lt;dataFile&gt;${project.build.directory}/jacoco.exec&lt;/dataFile&gt;
                              &lt;!-- Sets the output directory for the code coverage report. --&gt;
                              &lt;outputDirectory&gt;${project.reporting.outputDirectory}/jacoco-ut&lt;/outputDirectory&gt;
                          &lt;/configuration&gt;
                      &lt;/execution&gt;
                  &lt;/executions&gt;
              &lt;/plugin&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
                  &lt;artifactId&gt;maven-surefire-plugin&lt;/artifactId&gt;
                  &lt;version&gt;2.15&lt;/version&gt;
                  &lt;configuration&gt;
                      &lt;!-- Sets the VM argument line used when unit tests are run. --&gt;
                      &lt;argLine&gt;${surefireArgLine}&lt;/argLine&gt;
                      &lt;!-- Skips unit tests if the value of skip.unit.tests property is true --&gt;
                      &lt;skipTests&gt;${skip.unit.tests}&lt;/skipTests&gt;
                      &lt;!-- Excludes integration tests when unit tests are run. --&gt;
                      &lt;excludes&gt;
                          &lt;exclude&gt;**/IT*.java&lt;/exclude&gt;
                      &lt;/excludes&gt;
                  &lt;/configuration&gt;
              &lt;/plugin&gt;'
  </code></pre>
  
  <p>i am getting following exception </p>
  
  <pre><code>build   08-Sep-2016 15:33:06    INFO: Sensor JaCoCoSensor
  build   08-Sep-2016 15:33:06    INFO: No JaCoCo analysis of project coverage can be done since there is no class files.
  build   08-Sep-2016 15:33:06    INFO: Sensor JaCoCoSensor (done) | time=72ms
  build   08-Sep-2016 15:33:06    INFO: Sensor JaCoCoOverallSensor
  build   08-Sep-2016 15:33:06    INFO: Analysing /opt/shared/atlassian/bamboo/xml-data/build-dir/EV-LEV362-JOB1/enterprise/projects/target/jacoco.exec
  build   08-Sep-2016 15:33:06    INFO: No JaCoCo analysis of project coverage can be done since there is no class files.
  build   08-Sep-2016 15:33:06    INFO: Sensor JaCoCoOverallSensor (done) | time=100ms
  build   08-Sep-2016 15:33:06    INFO: Sensor XmlFileSensor
  </code></pre>