Need file from src/main/resources in generate-sources phase for annotation processor config

问题

I have an annotation processor that I need to give some configuration to tell it a few details about how I want it to generate source code. I spent a good deal of time trying to understand why the file was sitting in target/classes after the build, but I was getting an exception during annotation processing stating that the file did not, in fact, exist.

After much digging I finally figured out why the file (stored in src/main/resources/config) isn't getting copied over to target/classes/config for my annotation processor to read - generate-sources happens before process-resources in the build lifecycle, so the file isn't getting copied over in time for the annotation processor to see it during its run. (maven build lifecycle reference: http://maven.apache.org/ref/3.2.2/maven-core/lifecycles.html)

Here's a high level overview of what I'm trying to do:

I have a jar that I've built that processes annotations and generates interface classes from the information in the annotations to base a client api off of. The idea is that including that jar as a compile-time dependency should automatically generate this code for any project that uses these annotations (with as little-as-possible additional configuration in the client project's pom.xml).

How do I go about either:

Getting (at a minimum) the config.xml portion of process-resources to happen before generate-sources
Adding the file to the classpath of the annotation processor in some other way (we don't need this file in the output archive, so this might be better)
I am also open to other (clean) ways of getting configuration information into the annotation processor if there is a better way that I haven't thought of

I would prefer not to write a whole maven plugin for this if possible.

Edit: Here are the relevant parts of the <build> portion of my client pom per request:

<build>
    <finalName>OurApp</finalName>
    <resources>
        <resource>
            <!-- My config.xml file is located here -->
            <directory>src/main/resources</directory>
        </resource>
        <resource>
            <directory>src/main/webapp</directory>
            <includes>
                <include>*.*</include>
            </includes>
            <excludes><exclude>${project.build.directory}/generated-sources/**</exclude></excludes>
        </resource>
    </resources>
    <plugins>
        <!-- Omit Annotation Processor lib from the compilation phase because the code generated is destined for another, separate jar -->
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>${maven-compiler-plugin.version}</version>
            <executions>
              <execution>
                <id>annotation-processing</id>
                <phase>generate-sources</phase>
                <goals>
                  <goal>compile</goal>
                </goals>
                <configuration>
                  <proc>only</proc>
                </configuration>
              </execution>
              <!-- Compile the rest of the code in the normal compile phase -->
              <execution>
                <id>compile-without-generated-source</id>
                <phase>compile</phase>
                <goals>
                  <goal>compile</goal>
                </goals>
                <configuration>
                  <excludes><exclude>${project.build.directory}/generated-sources/**</exclude></excludes>
                  <proc>none</proc>
                  <!-- http://jira.codehaus.org/browse/MCOMPILER-230 because this doesn't
                       work in the opposite direction (setting failOnError in the other execution 
                       and leaving the default top-level value alone) -->
                  <failOnError>true</failOnError>
                </configuration>
              </execution>
            </executions>
            <configuration>
                <source>${java.version}</source>
                <target>${java.version}</target>
                <proc>only</proc>
                <failOnError>false</failOnError>
            </configuration>
        </plugin>
        <!-- package generated client into its own SOURCE jar -->
        <plugin>
            <artifactId>maven-assembly-plugin</artifactId>
            <version>2.4.1</version>
            <configuration>
                <descriptorRefs>
                    <descriptorRef>generated-client-source</descriptorRef>
                </descriptorRefs>
            </configuration>
            <dependencies>
                <dependency>
                    <groupId>com.package</groupId>
                    <artifactId>our-api</artifactId>
                    <version>${our-api.version}</version>
                </dependency>
            </dependencies>
            <executions>
                <execution>
                    <id>client-source</id>
                    <phase>package</phase>
                    <goals>
                        <goal>single</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

回答1:

So since this file is only needed at compile time, and since any attempt to draw it directly from the classpath was failing miserably, I decided to plop it in the project root, and add a compiler argument in Maven to point to the file.

  <compilerArgs>
      <compilerArg>-AconfigFilePath=${project.basedir}/config.xml</compilerArg>
  </compilerArgs>

Not quite as elegant as getting it off the classpath automatically, but still better than supplying all the configuration elements as separate properties.

Thanks for the suggestions

来源：https://stackoverflow.com/questions/25645944/need-file-from-src-main-resources-in-generate-sources-phase-for-annotation-proce

标签

java

maven

classpath

config

annotation-processing