Minify Maven Plugin

Minify Maven Plugin combines and minimizes your CSS and JavaScript files for faster page loading. It produces a merged and a minified version of your CSS and JavaScript resources which can be re-used across your project.

Under the hood, it uses the YUI Compressor and Google Closure Compiler but has a layer of abstraction around these tools which allows for other tools to be added in the future.

Benefits

Reduce HTTP Requests

80% of the end-user response time is spent on the front-end. Most of this time is tied up in downloading all the components in the page: images, stylesheets, scripts, etc. Reducing the number of components in turn reduces the number of HTTP requests required to render the page. This is the key to faster pages.

Combined files are a way to reduce the number of HTTP requests by combining all scripts into a single script, and similarly combining all CSS into a single stylesheet. Combining files is more challenging when the scripts and stylesheets vary from page to page, but making this part of your release process improves response times.

Compress JavaScript and CSS

Minification/compression is the practice of removing unnecessary characters from code to reduce its size thereby improving load times. A JavaScript compressor, in addition to removing comments and white-spaces, obfuscates local variables using the smallest possible variable name. This improves response time performance because the size of the downloaded file is reduced.

Usage

Configure your project's pom.xml to run the plugin during the project's build cycle.

<build>
  <plugins>
    <plugin>
      <groupId>com.samaxes.maven</groupId>
      <artifactId>minify-maven-plugin</artifactId>
      <version>1.7.6</version>
      <executions>
        <execution>
          <id>default-minify</id>
          <configuration>
            <charset>UTF-8</charset>
            <cssSourceFiles>
              <cssSourceFile>file-1.css</cssSourceFile>
              <!-- ... -->
              <cssSourceFile>file-n.css</cssSourceFile>
            </cssSourceFiles>
            <jsSourceFiles>
              <jsSourceFile>file-1.js</jsSourceFile>
              <!-- ... -->
              <jsSourceFile>file-n.js</jsSourceFile>
            </jsSourceFiles>
            <jsEngine>CLOSURE</jsEngine>
          </configuration>
          <goals>
            <goal>minify</goal>
          </goals>
        </execution>
      </executions>
    </plugin>
  </plugins>
</build>

Notice that the v1.6.X branch contains the last Java 6 compatible releases. Java 7 is required for new versions.
For more information, check the documentation or the demo applications.

License