Multi-Licensing¶

Multi-licensing allows you to apply two or more license headers to the same source file. This is common for projects dual-licensed under, for example, GPL and Apache 2.0, or that distribute code under both a commercial and an open-source license.

Using `<multi>`¶

Instead of <header> or <inlineHeader>, use the <multi> element inside a license set:

<licenseSets>
  <licenseSet>
    <multi>
      <header>GPL-2.txt</header>
      <separator>======================================================================</separator>
      <header>com/mycila/maven/plugin/license/templates/APACHE-2.txt</header>
    </multi>
  </licenseSet>
</licenseSets>

`<multi>` Options¶

Element	Description
`<preamble>`	Optional text placed before the first header
`<header>` (multiple)	Path or URL to a header template. Can be repeated.
`<inlineHeader>` (multiple)	Inline header text. Can be repeated.
`<separator>` (multiple)	Text placed between consecutive headers

Headers and separators are concatenated in declaration order to form the combined header.

Single Separator¶

If one separator is declared, it is inserted between every pair of headers:

<multi>
  <header>LICENSE-A.txt</header>
  <separator>---</separator>
  <header>LICENSE-B.txt</header>
  <header>LICENSE-C.txt</header>
</multi>

Results in: LICENSE-A + --- + LICENSE-B + --- + LICENSE-C

Multiple Separators¶

If multiple separators are declared, the first separator goes between licenses 1 and 2, the second between 2 and 3, and so on:

<multi>
  <header>LICENSE-A.txt</header>
  <separator>---first---</separator>
  <header>LICENSE-B.txt</header>
  <separator>---second---</separator>
  <header>LICENSE-C.txt</header>
</multi>

Preamble¶

Use <preamble> to add a human-readable explanation before the license headers:

<multi>
  <preamble><![CDATA[This product is dual-licensed under both the GPLv2 and Apache 2.0 License.]]></preamble>
  <header>GPL-2.txt</header>
  <separator>======================================================================</separator>
  <header>com/mycila/maven/plugin/license/templates/APACHE-2.txt</header>
</multi>

Full Example¶

<plugin>
  <groupId>com.mycila</groupId>
  <artifactId>license-maven-plugin</artifactId>
  <version>5.0.0</version>
  <configuration>
    <properties>
      <owner>Acme Corp</owner>
      <email>legal@acme.com</email>
    </properties>
    <licenseSets>
      <licenseSet>
        <multi>
          <preamble><![CDATA[Dual-licensed under GPL-2.0 and Apache-2.0.]]></preamble>
          <header>com/mycila/maven/plugin/license/templates/GPL-2.txt</header>
          <separator>======================================================================</separator>
          <header>com/mycila/maven/plugin/license/templates/APACHE-2.txt</header>
        </multi>
        <excludes>
          <exclude>**/README*</exclude>
          <exclude>src/test/resources/**</exclude>
        </excludes>
      </licenseSet>
    </licenseSets>
  </configuration>
</plugin>

Mixing Header and InlineHeader¶

You can mix file-based headers with inline headers:

<multi>
  <inlineHeader><![CDATA[
Copyright (C) ${year} ${owner}. All rights reserved.
Contact legal@acme.com for commercial licensing terms.
]]></inlineHeader>
  <separator>---</separator>
  <inlineHeader><![CDATA[
Also licensed under the MIT License.
Copyright (C) ${year} ${owner}
]]></inlineHeader>
</multi>