桃缶食べたい。

Maven プロジェクトのバージョンを Java から取得する方法

java.lang.Package.getImplementationVersion() を利用する

<build>
  <plugins>
    ...
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-jar-plugin</artifactId>
      <configuration>
        <archive>
          <manifest>
            <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
            <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
          </manifest>
        </archive>
      </configuration>
    </plugin>
    ...
  <plugins>
<build>

Manifest-Version: 1.0
Archiver-Version: Plexus Archiver
Created-By: Apache Maven
Built-By: momokan
Build-Jdk: 1.7.0_07
Specification-Title: sample
Specification-Version: 1.0-SNAPSHOT
Implementation-Title: sample
Implementation-Version: 1.0-SNAPSHOT
Implementation-Vendor-Id: sample

package sample;

public class Main {

	public static void main(String[] args) {
		System.out.println(Main.class.getPackage().getImplementationVersion());
	}

}

maven-antrun-plugin でファイルにバージョンを書き出す

<build>
  <plugins>
    ...
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-antrun-plugin</artifactId>
      <executions>
        <execution>
          <phase>initialize</phase>
          <goals>
            <goal>run</goal>
          </goals>
          <configuration>
            <tasks>
              <ant target="make-version-file" />
            </tasks>
          </configuration>
        </execution>
      </executions>
    </plugin>
    ...
  <plugins>
<build>

<project basedir=".">
  <target name="make-version-file">
    <xmlproperty file="pom.xml" prefix="pom.xml" />
    <echo message="PROJECT.VERSION=${pom.xml.project.version}" file="src/main/resources/sample/version.properties" />
  </target>
</project>

package sample;

import java.io.IOException;
import java.util.Properties;

public class Main {

	public static void main(String[] args) throws IOException {
		Properties	properties = new Properties();

		properties.load(Main.class.getResourceAsStream("version.properties"));

		System.out.println(properties.get("PROJECT.VERSION"));
	}

}

exec-maven-plugin でファイルにバージョンを書き出す

<build>
  <plugins>
    ...
    <plugin>
      <groupId>org.codehaus.mojo</groupId>
      <artifactId>exec-maven-plugin</artifactId>
      <executions>
        <execution>
          <phase>initialize</phase>
          <goals>
            <goal>exec</goal>
          </goals>
        </execution>
      </executions>
      <configuration>
        <executable>java</executable>
        <arguments>
          <argument>-cp</argument>
          <argument>lib</argument>
          <argument>sample.VersionStamp</argument>
          <argument>${project.version}</argument>
        </arguments>
      </configuration>
    </plugin>
    ...
  <plugins>
<build>

package sample;

import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;

public class VersionStamp {

	public static void main(String[] args) throws IOException {
		Properties		properties = new Properties();
		FileOutputStream	out = null;

		properties.put("PROJECT.VERSION", args[0]);

		try {
			out = new FileOutputStream("src/main/resources/sample/version.properties");
			properties.store(out, "VersionStamp");
		} finally {
			if (out != null) {
				try {
					out.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}

}

$ javac src/main/java/sample/VersionStamp.java
$ mkdir -p lib/sample
$ mv src/main/java/sample/VersionStamp.class lib/sample/