Cobertura - Ignore Logger Calls

I recently caught the testing bug and try to make sure that all the code I write is well tested and has 100% coverage. I use Cobertura, which is an excellent tool for measuring how much of your code is covered by tests. The coverage report it produces shows you what percentage of packages, classes, methods, lines and conditionals are covered and it highlights, in red, the lines in your source code which are not covered. I can now sleep better at night, knowing that my code is fully covered!

In order to use Cobertura, you just need to add the plugin to your project's POM file. When I first ran Cobertura, I found that it highlighted my logger.debug lines of code, so I had to tell it to ignore all logger calls, as follows:

<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>cobertura-maven-plugin</artifactId>
    <version>2.2</version>
    <configuration>
        <formats>
            <format>html</format>
        </formats>
        <instrumentation>
            <ignores>
                <ignore>org.apache.log4j.*</ignore>
            </ignores>
        </instrumentation>
    </configuration>
    <executions>
        <execution>
            <phase>deploy</phase>
            <goals>
                <goal>cobertura</goal>
            </goals>
        </execution>
    </executions>
</plugin>

You can run it using mvn cobertura:cobertura and then look at the report in target/site/cobertura/index.html.

Cobertura will also highlight some code which is impossible to test. For example, if a class has a private constructor (because it has static methods), then it will highlight the private constructor, even though you can't test it (unless you use reflection and change the constructor's accessibility, but that is going a bit too far!).

Maven Release

Prepare the release
Run the following command:

mvn release:prepare

This command will prompt you for a release version name, the next version name and will tag the code in CVS.

For example, if the current version in your pom is 1_10-SNAPSHOT, after running release:prepare, the version will be changed to 1_10, maven will commit (with a comment of [maven-release-plugin] prepare release myapp-1_10), tag as myapp-1_10, bump the pom version to 1_11-SNAPSHOT and commit it (with a comment of [maven-release-plugin] prepare for next development iteration).

release:prepare will also create a file called release.properties, shown below:

maven.username=sharfah
checkpoint.transformed-pom-for-release=OK
scm.tag=myapp-1_10
scm.url=scm:cvs:pserver::@sourceforge.uk.db.com:/data/cvsroot/apps:MyApp
checkpoint.transform-pom-for-development=OK
checkpoint.local-modifications-checked=OK
checkpoint.initialized=OK
checkpoint.checked-in-release-version=OK
checkpoint.tagged-release=OK
checkpoint.prepared-release=OK
checkpoint.check-in-development-version=OK

Perform the release
Run the following command:

mvn release:perform

This will use the release.properties file in order to check-out the tagged version from source control, compile, test and deploy it to the maven repository. If you have deleted your release.properties file, don't worry, you can just create a dummy one yourself, using the sample above.

If you want to skip site-deploy run the following command instead:

mvn release:perform -Dgoals=deploy

Related posts:
Quick Maven Commands
Skip Tests in Maven

Quick Maven Commands

Creating a Maven project
In order to create a new maven project called MyProject run the following command:

mvn archetype:create -DgroupId=fs.work -DartifactId=MyProject

This will create a new directory called MyProject with a pom.xml and the following tree structure:

MyProject
 |-->pom.xml
 |-->src
 |  |-->main
 |  |  |-->java
 |  |  |  |-->fs
 |  |  |  |  |-->work
 |  |  |  |  |  |-->App.java
 |  |-->test
 |  |  |-->java
 |  |  |  |-->fs
 |  |  |  |  |-->work
 |  |  |  |  |  |-->AppTest.java

The pom file looks like this:

  4.0.0
  fs.work
  MyProject
  jar
  1.0-SNAPSHOT
  MyProject
  http://maven.apache.org
  
    
      junit
      junit
      3.8.1
      test
    
  

Creating sub-modules
If you need to create sub-modules within your project, you need to change the packaging in the pom file (i.e. the "super" pom), to pom. Then, from within the MyProject directory issue the following commands to create sub-modules:

mvn archetype:create -DgroupId=fs.work -DartifactId=MyProjectWeb -Dpackaging=war
mvn archetype:create -DgroupId=fs.work -DartifactId=MyProjectModule1 -Dpackaging=jar

This creates the sub-modules and the directory tree now looks like this:

MyProject
 |-->pom.xml
 |-->src
 |  |-->main
 |  |  |-->java
 |  |  |  |-->fs
 |  |  |  |  |-->work
 |  |  |  |  |  |-->App.java
 |  |-->test
 |  |  |-->java
 |  |  |  |-->fs
 |  |  |  |  |-->work
 |  |  |  |  |  |-->AppTest.java
 |-->MyProjectModule1
 |  |-->pom.xml
 |  |-->src
 |  |  |-->main
 |  |  |  |-->java
 |  |  |  |  |-->fs
 |  |  |  |  |  |-->work
 |  |  |  |  |  |  |-->App.java
 |  |  |-->test
 |  |  |  |-->java
 |  |  |  |  |-->fs
 |  |  |  |  |  |-->work
 |  |  |  |  |  |  |-->AppTest.java
 |-->MyProjectWeb
 |  |-->pom.xml
 |  |-->src
 |  |  |-->main
 |  |  |  |-->java
 |  |  |  |  |-->fs
 |  |  |  |  |  |-->work
 |  |  |  |  |  |  |-->App.java
 |  |  |-->test
 |  |  |  |-->java
 |  |  |  |  |-->fs
 |  |  |  |  |  |-->work
 |  |  |  |  |  |  |-->AppTest.java

The pom file for MyProjectModule1 contains a reference to the parent and looks like this:

  
    MyProject
    fs.work
    1.0-SNAPSHOT
  
  4.0.0
  fs.work
  MyProjectModule1
  MyProjectModule1
  1.0-SNAPSHOT
  http://maven.apache.org
  
    
      junit
      junit
      3.8.1
      test
    
  

Deploying a jar to the repository
If you have a jar file called myarchive.jar which you want to upload to your maven repository, use the following command:

mvn deploy:deploy-file -Durl=scp://hostname/dir/to/maven -DrepositoryId=fs.repo -Dfile=myarchive.jar -DgroupId=fs.work -DartifactId=myarchive -Dversion=1.0 -Dpackaging=jar

This will create dir/to/maven/fs/work/myarchive/1.0/myarchive-1.0.jar in the maven repository.

Creating a dependency
To create a dependency on myarchive.jar, add the following dependency to your pom:

  fs.work
  myarchive
  1.0

Generating Eclipse .project and .classpath files
Use the following command:

mvn eclipse:eclipse

Skipping tests
To skip tests use the property maven.test.skip=true.

mvn -Dmaven.test.skip=true install

Release a project
Two commands must be invoked, in the following order:

mvn release:prepare
mvn release:perform

Other commands

mvn install
mvn clean
mvn compile
mvn jar:jar

Skip Tests in Maven [Tip]

If your tests are failing and you can't be bothered to fix them, this handy tip will show you how you can skip tests and build your Maven project straightaway!

Simply add the property -Dmaven.test.skip=true to your Maven command. Here is an example:

mvn -Dmaven.test.skip=true install

The compiler will not compile the test sources and will not run your JUnit tests:

[INFO] [compiler:testCompile]

[INFO] Not compiling test sources
[INFO] [surefire:test]
[INFO] Tests are skipped.

But of course, your test classes should always run, right?

Reference:

http://maven.apache.org/general.html