Using fileExtensions property

If you want to compress jsp files as well (or any other file type, this is just for example), then you need to update your pom file like below:

<build>
  <plugins>
    <plugin>
      <groupId>com.github.hazendaz.maven</groupId>
      <artifactId>htmlcompressor-maven-plugin</artifactId>
      <version>2.1.1-SNAPSHOT</version>
      <configuration>
        <goalPrefix>htmlcompressor</goalPrefix>
        <fileExtensions>
          <fileExtension>htm</fileExtension>
          <fileExtension>html</fileExtension>
          <fileExtension>jsp</fileExtension>
        </fileExtensions>
      </configuration>
    </plugin>
  </plugins>
</build>

All other file types will be ignored during processing.

For more details about configuration description please refer htmlcompressor site.