A Maven plugin that provides the ability to transparently divert your build directory to another location via symbolic links.

See the CHANGELOG for change information.

Basic Usage

Add the plugin to your project

Add the plugin to the build section of your pom's project :

<plugin>
  <groupId>com.github.jdelker.maven.plugins</groupId>
  <artifactId>tmpbuild-maven-plugin</artifactId>
  <version>1.0</version>
  <executions>
    <execution>
      <id>link</id>
      <goals>
        <goal>link</goal>
      </goals>
      <phase>initialize</phase>
    </execution>
    <execution>
      <id>clean</id>
      <goals>
        <goal>clean</goal>
      </goals>
      <phase>clean</phase>
    </execution>
  </executions>
</plugin>

Motivation

This plugin was crafted for a partciular use-case, where the maven build directory (usually ./target) should be placed on another filesystems, but without manifesting any specific path in the POM.

A situation where this could come handy is, when the project is located on a slow or write-sensitive device (e.g. flash-card). By using this plugin, the build directory is diverted to a given location, without affecting the general functionality of the project.

Any obvious attempt to achieve this by setting maven's project.build.directory property, fails unfortunately. Maven does not allow to alter this variable from either the command line or through non-project profiles.

Thus, the idea for this plugin, to transparantly divert the build directory through a plugin.

Documentation

Unless the plugin is configured explicitly for divertion, it behaves completely neutral and does not perform any action. This allows to add it as a general plugin to some Super-POM, even if only some users are actually using it.

As soon as the property tmpbuild.directory is set, the plugin creates the project's build directory at the given location, together with a symbolic link pointing there from the original directory.

The property can be set either through the maven command line, like -Dtmpbuild.directory=/my/superfast/drive, or by defining a personal profile in settings.xml like so

<profile>
  <id>tmpbuild</id>
  <properties>
    <tmpbuild.directory>/my/superfast/drive</tmpbuild.directory>
  </properties>
</profile>

and activating that profile either automatically or via -P tmpbuild.

IMPORTANT As symbolic links are used, this plugin won't work on Windows out-of-the-box. Windows NTFS does actually have support for symbolic links, but they are tied to some restrictions, which makes them hard to use.

Example

Your maven project is located at /my/slow/drive/myproject. The tmpbuild plugin has been added to the pom.xml as described above.

If you perform a build as usual, maven creates (and eventually cleans) the build directory at /my/slow/drive/myproject/target - just as always.

Now you build the project again, but set ´tmpbuild.directory=/my/fast/drive. During project initialization, the build directory is created at /my/fast/drive/targetand linked to/my/slow/drive/myproject/target`. The project is then build as usual, but with all files being diverted to the fast drive.