maven-compiler-plugin: change <outputDirectory> per execution

Question

situation

I have XML files which I need to deal with in my GUI (JavaXF) and in my JavaStoredProcedures in my oracle12c database.

In the GUI I want to use properties bindings. So I configured the maven-jaxb2-plugin to generate the sources with properties.

The database on the other hand does not support Java8 therefore is configured a second execution for the maven-jaxb2-plugin to generate the sources without properties in a different folder ending up with two folders containing the same Java-classes in the same packages in different folders.

So what I have now looks like this:

 project
 \-target
   \-generated-sources
     +-java7
     | \-package.with.java.files
     |   \-Java7-compilabe-sources*
     \-java8
       \-package.with.java.files
         \-Java8-compilabe-sources*

What I want to do next is to compile the two folders target/generated-sources/java7 and target/generated-sources/java8 to different output folders target/java7/classes and target/java8/classes respectively within different executions of the maven-compiler-plugin.

But I'm not able to change the output directory of the maven-compiler-plugin for a single execution.

This is my current configuration of the maven-compiler-plugin:

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
      <verbose>true</verbose>
      <fork>true</fork>
      <encoding>ISO-8859-1</encoding>
    </configuration>
    <executions>
     <execution>
      <id>java8</id>
      <configuration>
        <source>1.8</source>
        <target>1.8</target>
        <executable>${jdk-1.8}/bin/javac</executable>
        <compilerVersion>1.8</compilerVersion>
        <sourceDirectory>${project.build.directory}/generated-sources/java8</sourceDirectory>
        <outputDirectory>${basedir}/target/java8/classes</outputDirectory>
      </configuration>
     </execution>
    </executions>
  </plugin>

But from the maven output it looks like it does not respect either one of <sourceDirectory> nor <outputDirectory>:

[INFO] ------------------------------------------------------------------------
[INFO] Building MyProject 6.0.5
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ MyProject ---
[INFO] Deleting /ProjectRoot/target
[INFO]
[INFO] --- maven-jaxb2-plugin:0.13.1:generate (Java8) @ MyProject ---
[INFO] Up-to-date check for source resources [[file:/ProjectRoot/src/main/xsd/parad.xsd, file:/ProjectRoot/src/main/xjb/bindings.xml, file:/ProjectRoot/pom.xml]] and target resources [[]].
[INFO] Sources are not up-to-date, XJC will be executed.
[INFO] Episode file [/ProjectRoot/target\generated-sources\java8\META-INF\sun-jaxb.episode] was augmented with if-exists="true" attributes.
[INFO]
[INFO] --- maven-jaxb2-plugin:0.13.1:generate (Java7) @ MyProject ---
[INFO] Up-to-date check for source resources [[file:/ProjectRoot/src/main/xsd/parad.xsd, file:/ProjectRoot/src/main/xjb/bindings.xml, file:/ProjectRoot/pom.xml]] and target resources [[]].
[INFO] Sources are not up-to-date, XJC will be executed.
[INFO] Episode file [/ProjectRoot/target\generated-sources\java7\META-INF\sun-jaxb.episode] was augmented with if-exists="true" attributes.
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ MyProject ---
[WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 1 resource
[INFO] Copying 1 resource
[INFO] Copying 1 resource
[INFO] Copying 1 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ MyProject ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 114 source files to /ProjectRoot/target\classes

findings

• the compiler pluging does not show the execution ID (as the maven-jaxb2-plugin does)
• the compiler pluging compiles both target/generated-sources/java7 and target/generated-sources/java8 (each contains 57 *.java files) although <sourceDirectory> is given in execution/config
• the compiler pluging compiles to target/classes although <outputDirectory> is given in execution/config

question

how do I force maven to compile each of target/generated-sources/java7 and target/generated-sources/java8 to its own target folder separately?

additional info

$ mvn --version
Apache Maven 3.3.3 (7994120775791599e205a5524ec3e0dfe41d4a06; 2015-04-22T13:57:37+02:00)

Answer 1

I solved the problem by usting the maven-antrun-plugin.

first I turend off compilation by excluding all files:

    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
      <verbose>true</verbose>
      <fork>true</fork>
      <encoding>ISO-8859-1</encoding>
      <source>1.8</source>
      <target>1.8</target>
      <executable>${jdk-1.8}/bin/javac</executable>
      <compilerVersion>1.8</compilerVersion>
      <excludes>
        <exclude>**/*.*</exclude>
      </excludes>
    </configuration>

I also turned of the maven-jar-plugin

    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-jar-plugin</artifactId>
    <version>3.0.2</version>
    <executions>
      <execution>
        <id>default-jar</id>
        <phase>never</phase>
        <configuration>
          <finalName>unwanted</finalName>
          <classifier>unwanted</classifier>
        </configuration>
      </execution>
    </executions>

then I configured separate executions in the maven-antrun-plugin to compile eache source folder and create the separate jars.

what's left is to configure the maven-deploy-plugin so that the two jars (and their source jars) are correctly placed in the maven repository so that they can be fetched as dependencies.