We have seen how simple it is to create a Gradle build job in Jenkins. We will now add Checkstyle and PMD plugins to our project for quality checking purposes. There are different approaches that we can follow in order to use these plugins. We can directly add these plugins to Jenkins and run it for our project, or we can use Gradle Checkstyle and PMD plugins and evaluate the project.

We will use the Gradle approach to add Checkstyle and PMD plugins for code quality check, and execute this using Jenkins. Let's create two Gradle files, one for Checkstyle and the other for PMD:

build_checkstyle.gradle

apply plugin: 'groovy'
apply plugin: 'eclipse'
apply plugin: 'checkstyle'


version = '1.0'

repositories {
  mavenCentral()
}
checkstyle {
  toolVersion = 6.5
  ignoreFailures = true
}


dependencies {
  compile gradleApi()
  compile localGroovy()
  compile group: 'commons-collections', name: 'commons-collections', version: '3.2'
  testCompile group: 'junit', name: 'junit', version: '4.+'
}

In the build file, we have added additional configuration in the closure checkstyle { … }. If the source code does not pass the CheckStyle rules, it results in build failure. To ignore any build failure due to Checkstyle rule violation; we need to add the ignoreFailures=true property in the checkstyle closure.

Checkstyle plugin provides the following tasks:

For Checkstyle plugin, we need a checkstyle.xml file in the <Project>/config/checkstyle/ directory. This is the default location. You can find a sample checkstyle.xml at: https://github.com/google/google-api-java-client/blob/dev/checkstyle.xml.

It provides a standard quality checks for projects. You can write customized checkstyle.xml for your requirements as well.

To use PMD plugin, you can copy the above file and replace checkstyle closure with pmd closure and remove the toolVersion property. If you don't specify a version, Gradle downloads PMD version 5.1.1 by default. You will also need to add apply plugin: pmd.

build_pmd.gradle

apply plugin: 'groovy'
apply plugin: 'pmd'

version = '1.0'

repositories {
  mavenCentral()
}

pmd{
  ignoreFailures = true
}

dependencies {
  compile gradleApi()
  compile localGroovy()
  compile group: 'commons-collections', name: 'commons-collections', version: '3.2'
  testCompile group: 'junit', name: 'junit', version: '4.+'
}

PMD plugin provides the following tasks:

Both the Checkstyle and PMD plugins can be executed using check task.

We will create a new project QualityCheck and add the following files to the project:

Checkstyle and PMD plugin are executed in Java code, so we will add some sample Java files under the src/main/java/ directory. To create a build step in Jenkins, we will create a build step to execute a Checkstyle task (check task), as shown in Figure 7.15. You can repeat the same steps for PMD plugin.

For a new configuration, Root Build script is set to ${workspace}/Chapter7/QualityCheck. Also, we added the Build file name in the text box as build_checkstyle.gradle.

Figure 7.15

Save this configuration and execute the job again. As configured, build_checkstyle.gradle file executed on java source code and generated CheckStyle reports for it. You can find the reports under ${workspace}Chapter7QualityCheckuild eportscheckstylemain.xml