Important note: This project is in early stage. It's a PoC published for evaluation purpose with your help! If the idea is successful, the project may be renamed and the code base will be completely rewritten, otherwise this repository will be deleted. Even though the project is not released yet, you can still give it a try and send us your feedback, you are very welcome!

JCQL (Java Code Query Linter) makes it possible to query Java source code with SQL. This allows you to answer questions like:

• Is there any class that has no unit tests?
• What is the longest class name?
• Is there any class that has more than 20 methods?

It is a static analysis tool that gives you precious insights on your code base in order to improve its quality. JCQL can be easily integrated in your build process to continuously check if your coding rules are respected.

JCQL creates a relational database from a given Java code base. Once you have created the relational model, you can query it with standard SQL. The relational model has been designed to be intuitive, natural and easy to understand and query:

SELECT i.NAME as name, COUNT(m.ID) as nbMethods
FROM INTERFACE i, METHOD m
WHERE m.TYPE_ID = i.ID GROUP BY i.ID HAVING COUNT(m.ID) > 20;

SELECT c.NAME as name, COUNT(c.ID) as nbConstructors
FROM CLASS c, CONSTRUCTOR co
WHERE co.TYPE_ID = c.ID GROUP BY c.NAME HAVING COUNT(c.ID) > 5;

SELECT t.NAME as typeName, m.NAME as methodName, COUNT(m.ID) as nbParams
FROM TYPE t, METHOD m, PARAMETER p
WHERE p.METHOD_ID = m.ID and m.TYPE_ID = t.ID
GROUP BY m.ID HAVING COUNT(m.ID) > 5;

SELECT name, LENGTH(name) as length from CLASS ORDER BY length DESC LIMIT 10;

JCQL is in early stage and is not released yet. You can still try the first snapshot version:

• jcql-core: download jar
• jcql-shell: download jar

Note: JCQL require Java 1.8+

JCQL provides two ways to create a relational database from a given Java code base:

Add the following repository in your pom.xml :

<repository>
    <id>ossrh</id>
    <url>https://oss.sonatype.org/content/repositories/snapshots</url>
</repository>

and run the following command in the root folder of the project you want to analyse:

mvn io.github.benas:jcql-maven-plugin:0.1-SNAPSHOT:index

This will create a file named jcql.db in the target directory that you can query with your favorite SQL client or the one provided by JCQL.

Run the following command:

java -jar jcql-core-{latest-version}.jar /path/to/project/to/analyse /path/to/database/directory

Once you have indexed your Java code in a relational format, you can query it with plain SQL:

Open the jcql.db file with your favorite SQL client and start writing queries. For example, you can use Sqlite tools or Sqlite browser.

The JCQL shell is a command line tool that allows you to write queries against the generated database.

You can start it as follows:

java -jar /path/to/jcql-shell-{latest-version}.jar /path/to/jcql.db

• JCQL tools use the great java-parser library to parse Java code and transform it a relational model.

• JCQL tools use Sqlite to store and query relational data about Java code