milleruntime commented on a change in pull request #206: Checkstyle import control blog post. Fixes #149 URL: https://github.com/apache/accumulo-website/pull/206#discussion_r343382753
########## File path: _posts/blog/2019-11-04-checkstyle-import-control.md ########## @@ -0,0 +1,93 @@ +--- +title: "Checking API use" +--- + +Accumulo follows [SemVer] across versions with the declaration of a public API. Code not in the public API should be +considered unstable, at risk of changing between versions. The packages included in the public API are [listed on the website][api] +but may not always be considered when developing using Accumulo code. This blog post explains how to setup a Maven project +to automatically detect when Accumulo 2.0 code used in the project is outside of the public API. + +## Checkstyle Plugin + +First add the checkstyle Maven plugin to your pom. + +```xml +<plugin> + <!-- This was added to ensure project only uses public API --> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-checkstyle-plugin</artifactId> + <version>3.1.0</version> + <configuration> + <configLocation>checkstyle.xml</configLocation> + </configuration> + <dependencies> + <dependency> + <groupId>com.puppycrawl.tools</groupId> + <artifactId>checkstyle</artifactId> + <version>8.23</version> + </dependency> + </dependencies> + <executions> + <execution> + <id>check-style</id> + <goals> + <goal>check</goal> + </goals> + </execution> + </executions> + </plugin> +``` +The plugin version is the latest at the time of this post. For more information see the website for +the [Apache Maven Checkstyle Plugin][plugin]. The configuration above adds the plugin to ```check``` execution goal +so it will always run with your build. + +Create the configuration file specified above: ```checkstyle.xml``` + +### checkstyle.xml + +```xml +<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://www.puppycrawl.com/dtds/configuration_1_3.dtd";> +<module name="Checker"> + <property name="charset" value="UTF-8"/> + <module name="TreeWalker"> + <!--check that only Accumulo public APIs are imported--> + <module name="ImportControl"> + <property name="file" value="import-control.xml"/> + </module> + </module> +</module> +``` +This file sets up the ImportControl module. + +## Import Control Configuration + +Create the second file specified above, ```import-control.xml``` and copy the configuration below: +```xml +<!DOCTYPE import-control PUBLIC + "-//Checkstyle//DTD ImportControl Configuration 1.4//EN" + "https://checkstyle.org/dtds/import_control_1_4.dtd";> + +<!-- This checkstyle rule is configured to ensure only use of Accumulo API --> +<import-control pkg="org.apache.accumulo.testing" strategyOnMismatch="allowed"> Review comment: > And, is it worth mentioning what the `strategyOnMismatch` does? I'm kind of curious myself. I don't remember exactly why this was needed so I didn't mention it. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
