How I migrated a legacy project from Ant to Maven

This is about a legacy project which I recently was assigned to. I was asked to migrate its building process from Ant to Maven.

After all, it was less difficult than I thought at first glance. I did a very little research and obtained some ideas from here. Let’s see.

1. Create a maven project.

I used the archetype for web projects:

mvn archetype:generate -DgroupId={project-packaging}
   -DartifactId={project-name}
   -DarchetypeArtifactId=maven-archetype-webapp
   -DinteractiveMode=false

2. Migrate dependencies.

Then, (apparently) the most difficult part: guessing the maven coordinates for a pile of jars with no version! Fortunately, I found an easy way to do it: using the checksum search in Nexus at repository.sonatype.org.

a. Checksum tool.

In my case, I chose FCIV utility for Windows. I downloaded the exe file and placed it in C:\Windows\System32 (ready to be used from any path).

b. Generate jar checksum.

I iterated over all external dependencies (also to check if jars with versions have the correct one). For example, for spring-core.jar:

i. I ran on a Windows command console at the containing folder:

fciv spring-core.jar -sha1

and got 3a4bf426a3d8dc0766a3a9c70a33f6c3ac8db144.

ii. I searched using that checksum at Sonatype RSO and got 2.5.6.SEC02 version for spring-core artifact.

iii. I copied Maven dependency and pasted in my pom.xml.

c. Unknown dependencies.

There were few dependencies which I couldn’t resolve. So I created a local repository in my pom.xml:

<repositories>
   <repository>
     <id>local-repo</id>
     <url>file://${basedir}/local-repo</url>
   </repository>
</repositories>

and installed those original jars there, using:

mvn install:install-file -Dfile=<path-to-file> -DgroupId=<myGroup> \
   -DartifactId=<myArtifactId> -Dversion=<myVersion> \
   -Dpackaging=<myPackaging> -DlocalRepositoryPath=<path>

See more at “Adding a custom jar as a maven dependency”.

3. Moving source files.

Finally, I moved source files under src/main/java default path, and the web content into webapp folder.

That was all, and it worked out on the first try!