JaCoCo comes with Ant tasks to launch Java programs with execution recording and for creating coverage reports from the recorded data. The JaCoCo Ant tasks require
All tasks are defined in jacocoant.jar
(which is part of the
distribution) and can be included in your Ant scripts with the usual
taskdef
declaration:
1<project name="Example" xmlns:jacoco="antlib:org.jacoco.ant"> 2 3 <taskdef uri="antlib:org.jacoco.ant" resource="org/jacoco/ant/antlib.xml"> 4 <classpath> 5 <pathelement location="path_to_jacoco/lib/jacocoant.jar"/> 6 </classpath> 7 </taskdef> 8 9 ... 10 11</project>
Alternatively you might also place the jacocoant.jar
in your
Ant ANT_HOME/lib
folder. If you use the name space URI
antlib:org.jacoco.ant
for JaCoCo tasks Ant will find them
automatically without the taskdef
declaration above.
Declaring a XML namespace for JaCoCo tasks is optional but always recommended
if you mix tasks from different libraries. All subsequent examples use the
jacoco
prefix declared above.
coverage
The standard Ant tasks to launch Java programs are java
and
junit
. To add code coverage recording to these tasks they can
simply be wrapped with the coverage
task as shown in the
following examples:
1<jacoco:coverage> 2 <java classname="org.jacoco.examples.HelloJaCoCo" fork="true"> 3 <classpath> 4 <pathelement location="./bin"/> 5 </classpath> 6 </java> 7</jacoco:coverage> 8 9 10<jacoco:coverage> 11 <junit fork="true" forkmode="once"> 12 <test name="org.jacoco.examples.HelloJaCoCoTest"/> 13 <classpath> 14 <pathelement location="./bin"/> 15 </classpath> 16 </junit> 17</jacoco:coverage>
Resulting coverage information is collected during execution and written
to a file when the process terminates. Note the fork
attribute
above in the wrapped java
task.
The nested task always has to declare fork="true"
, otherwise the
coverage
task can't record coverage information and will fail.
In addition the junit
task should declare
forkmode="once"
to avoid starting a new JVM for every single test
case and decreasing execution performance dramatically (unless this is
required by the nature of the test cases).
The coverage task must wrap exactly one task. While it typically works without any configuration, the behavior can be adjusted with some optional attributes:
Attribute | Description | Default |
file |
Path to the output file for execution data. | jacoco.exec |
merge |
If set to true and the execution data file already
exists, coverage data is merged to the existing file. If set to
false , an existing execution data file will be replaced.
|
true |
includes |
A list of class names that should be included in execution analysis.
The list entries are separated by a vertical bar (| ) and
may use wildcard characters (* and ? ).
Except for performance optimization or technical corner cases this
option is normally not required.
|
* (all classes) |
excludes |
A list of class names that should be excluded from execution analysis.
The list entries are separated by a vertical bar (| ) and
may use wildcard characters (* and ? ).
Except for performance optimization or technical corner cases this
option is normally not required.
|
empty (no excluded classes) |
exclclassloader |
A list of class loader names, that should be excluded from execution
analysis. The list entries are separated by a vertical bar
(| ) and may use wildcard characters (* and
? ). This option might be required in case of special
frameworks that conflict with JaCoCo code instrumentation, in
particular class loaders that do not have access to the Java runtime
classes.
|
sun.reflect.DelegatingClassLoader |
agent
If the coverage
task is not suitable for your launch target, you
might alternatively use the agent
task to create the Java agent
parameter. The following example defines a Ant property with the name
agentvmparam
that can be directly used as a Java VM parameter:
1<jacoco:agent property="agentvmparam"/>
This task has the same attributes as the coverage
task plus an
additional property to specify the target property name:
Attribute | Description | Default |
property |
Name of the Ant property to set. | none (required) |
All attributes of the coverage task. |
report
Finally different reports can be created with the report
task.
A report task declaration consists of different sections, two specify the
input data, additional ones specify the output formats:
1<jacoco:report> 2 3 <executiondata> 4 <file file="jacoco.exec"/> 5 </executiondata> 6 7 <structure name="Example Project"> 8 <classfiles> 9 <fileset dir="bin"/> 10 </classfiles> 11 <sourcefiles encoding="UTF-8"> 12 <fileset dir="src"/> 13 </sourcefiles> 14 </structure> 15 16 <html destdir="report"/> 17 18</jacoco:report>
As you can see from the example above the report
task is based
on several nested elements:
executiondata
Within this element Ant resources and resource collections can be specified, that represent JaCoCo execution data files. If more than one execution data file is specified, execution data is combined. A particular piece of code is considered executed when it is marked as such in any of the input files.
structure
This element defines the report structure. It might contain the following nested elements:
classfiles
: Container element for Ant resources and resource
collections that can specify Java class files, JAR files or directories
containing class files.sourcefiles
: Optional container element for Ant resources and
resource collections that specify corresponding source files. The element
has an optional attribute encoding
to specify the character
encoding of the source files. If no encoding is given, the platform default
is used. If source files are specified, some report formats include
highlighted source code.
The structure can be refined with a hierarchy of group
elements.
This way the coverage report can reflect different modules of a software
project. For each group element the corresponding class and source files can
be specified separately. For example, the build script of JaCoCo itself
contains the following declaration to separate the different bundles in the
report (see the resulting report):
1<structure name="JaCoCo"> 2 <group name="org.jacoco.core"> 3 <classfiles> 4 <path refid="bundle-org.jacoco.core"/> 5 </classfiles> 6 <sourcefiles> 7 <fileset dir="${workspace.dir}/org.jacoco.core/src"/> 8 </sourcefiles> 9 </group> 10 <group name="org.jacoco.report"> 11 <classfiles> 12 <path refid="bundle-org.jacoco.report"/> 13 </classfiles> 14 <sourcefiles> 15 <fileset dir="${workspace.dir}/org.jacoco.report/src"/> 16 </sourcefiles> 17 </group> 18 19 ... 20 21</structure>
html
Create a multi-page report in HTML format.
Attribute | Description | Default |
destdir |
Directory to create the report in. | none (required) |
footer |
Footer text for each report page. | No footer |
encoding |
Encoding of the generated HTML pages. | UTF-8 |
xml
Create a single-file report in XML format.
Attribute | Description | Default |
destfile |
Location to write the report file to. | none (required) |
encoding |
Encoding of the generated XML document. | UTF-8 |
csv
Create single-file report in CSV format.
Attribute | Description | Default |
destfile |
Location to write the report file to. | none (required) |
encoding |
Encoding of the generated CSV document. | UTF-8 |