Ralph Ralph - 17 days ago 5
Java Question

Generate a Version.java file in Maven

I have a Java project that I build using an Ant script. I am trying to convert the project to Maven.

One of the tasks generates a Java source file called Version.java that contains a static String representation of the compilation timestamp, as follows:

package com.foo.bar;
public final class Version {
public static String VERSION="100301.1046";
}


The Ant task is very simple:

<target name="version" depends="init" description="Create Version.java">
<echo file="src/${package.dir}/Version.java" message="package ${package.name};${line.separator}" />
<echo file="src/${package.dir}/Version.java" append="true" message="public final class Version {${line.separator}" />
<echo file="src/${package.dir}/Version.java"
append="true"
message=" public static String VERSION=&quot;${buildtime}&quot;;${line.separator}" />
<echo file="src/${package.dir}/Version.java" append="true" message="}${line.separator}" />
<echo message="BUILD ${buildtime}" />
</target>


Is it possible to do something similar in Maven, using generate-sources, or some other simple method?

Answer

After more Googling, I came up with this (in the pom.xml):

<plugins>
  ...
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-antrun-plugin</artifactId>
    <version>1.3</version>
    <executions>
      <execution>
        <goals>
          <goal>run</goal>
        </goals>
        <phase>generate-sources</phase>
        <configuration>
          <tasks>
            <property name="src.dir" value="${project.build.sourceDirectory}" />
            <property name="package.dir" value="com/foo/bar" />
            <property name="package.name" value="com.foo.bar" />
            <property name="buildtime" value="${maven.build.timestamp}" />

            <echo file="${src.dir}/${package.dir}/Version.java" message="package ${package.name};${line.separator}" />
            <echo file="${src.dir}/${package.dir}/Version.java" append="true" message="public final class Version {${line.separator}" />
            <echo file="${src.dir}/${package.dir}/Version.java" append="true"
              message=" public static String VERSION=&quot;${buildtime}&quot;;${line.separator}" />
            <echo file="${src.dir}/${package.dir}/Version.java" append="true" message="}${line.separator}" />
            <echo message="BUILD ${buildtime}" />
          </tasks>
        </configuration>
      </execution>
    </executions>
  </plugin>
  ...
</plugins>

It seems to work well and produces this Java file:

package com.foo.bar;
public final class Version {
 public static String VERSION="100318.1211";
}