Compiling Generated .java Into .class Files

[pbtura]

I'm seeing some strange behavior when trying to use this plugin and I'm not sure if it is a bug or if I am just doing something wrong. When I run a maven build, the generated .java files are being created as expected but there are no corresponding .class files. The project is getting packaged into a library jar, so if the class files are missing, other projects that use the jar will not be able to use the generated files. What do I need to do to make sure the class files get created?

Here is what my pom looks like currently:

   <plugin>
   	    <groupId>org.bsc.maven</groupId>
   	    <artifactId>maven-processor-plugin</artifactId>
   	   <version>4.5-jdk8</version>
   	    <executions>
   	        <execution>
   	            <id>process</id>
   	            <goals>
   	                <goal>process</goal>
   	            </goals>
   	            <phase>generate-sources</phase>
   	            <configuration>
   	            	<outputDirectory>${project.build.directory}/generated-sources/annotations</outputDirectory>
   	            	<outputClassDirectory>${project.build.directory}/generated-sources/classes</outputClassDirectory>
   	            	<addOutputDirectoryToCompilationSources>true</addOutputDirectoryToCompilationSources>
   	                <processors>
   	                    <processor>org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor</processor>
   	                </processors>
   	                <overwrite>true</overwrite>
   	            </configuration>
   	        </execution>
   	    </executions>
   	    <dependencies>
   	        <dependency>
   	            <groupId>org.hibernate</groupId>
   	            <artifactId>hibernate-jpamodelgen</artifactId>
   	            <version>5.3.13.Final</version>		            
   	        </dependency>		       
   	    </dependencies>
   	</plugin>
   	
   	<plugin>
       	<groupId>org.apache.maven.plugins</groupId>
   	    <artifactId>maven-compiler-plugin</artifactId>		    	
   	    <executions>
   	          <execution>
   	            <id>generate-annotated</id>
   	            <phase>generate-sources</phase>
   	            <goals>
   	              <goal>compile</goal>
   	            </goals>
   	            <configuration>
   			       <compilerArgument>-proc:none</compilerArgument>
   			    </configuration>
   	          </execution>
   		</executions>
   	</plugin>		
   	<plugin>
   	        <groupId>org.codehaus.mojo</groupId>
   	        <artifactId>build-helper-maven-plugin</artifactId>	        
   	        <executions>
   	          <execution>
   	            <id>add-source</id>
   	            <phase>generate-sources</phase>
   	            <goals>
   	              <goal>add-source</goal>
   	            </goals>
   	            <configuration> 
   	              <sources>	              
   	                <source>${project.build.directory}/generated-sources/annotations</source>	               
   	              </sources>	            
   	            </configuration>
   	          </execution>
   	        </executions>
   	</plugin>

When I run 'mvn clean package' everything passes and I see the generated sources in generated-sources/annotations. When I look at generated-sources/classes however the directory is empty. The resulting jar also lacks any of the generated class files.

[bsorrentino]

Hi @pbtura let me investigate

[pbtura]

I spent some time experimenting with a test project to see if I could isolate the issue. I made two discoveries that might be helpful. First, the <outputClassDirectory> tag does not seem to work. It will create a directory with that name but no files will ever be placed in it. Second, and more important, the <outputDirectory> tag seems to be the source of the problem. I changed the value of that tag from

${project.build.directory}/generated-sources/annotations

to

${project.build.directory}/generated-sources/java

I re-ran the build and the .class files for the generated source were created in the ${project.build.directory}/classes directory.

${project.build.directory}/generated-sources/annotations is the default output location when doing annotation processing via the maven-compiler-plugin. I wonder if there is some sort of conflict, even though the proc argument is set to none?

[bsorrentino]

Hi @pbtura thanks for help, I’ll focus on your findings

[bsorrentino]

Hi @pbtura

in this branch I've performed a test to replicate your issue

I haven't been able to replicate the error and in my test all seems work well. Take a look to the branch. Below a summary of plugin's configuration

    <plugin>
        <groupId>org.bsc.maven</groupId>
        <artifactId>maven-processor-plugin</artifactId>
        <executions>
            <execution>

                <id>process</id>
                <goals>
                    <goal>process</goal>
                </goals>
                <phase>process-sources</phase>
                <configuration>
                    <addOutputDirectoryToCompilationSources>true</addOutputDirectoryToCompilationSources>
                    <failOnError>false</failOnError>
                    <processors>
                        <processor>org.bsc.maven.plugin.processor.test.TestGenerateSourceProcessor</processor>
                    </processors>
                </configuration>

            </execution>
        </executions>
    </plugin>

Let me know

[pbtura]

Ok, I will check that out when I get some time. In the mean time, I posted my sample project to github if you want to try running some tests against it. The project is located here: https://github.com/pbtura/jpa-test
If you do 'mvn clean package -P broken' you should see that the java sources get generated but the corresponding class files for some of them such as Country_ and StateProvince_ will be missing.

[bsorrentino]

Hi @pbtura I've cloned your project jpa-test. I've applied the following update to the pom.xml

1. Removed profiles
2. Removed <outputDirectory> from plugin configuration
3. Removed build-helper-maven-plugin

And all worked as expected. Take note that the default plugin output path is ${project.build.directory}/generated-sources/apt

Below the updated pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">

	<modelVersion>4.0.0</modelVersion>
	<groupId>com.tura</groupId>
	<artifactId>jpa-test</artifactId>
	<version>0.0.1</version>
	<packaging>jar</packaging>

	<properties>
		<classes.generated.path>${project.build.directory}/generated-sources/annotations</classes.generated.path>
	</properties>

	<dependencies>
		<dependency>
			<groupId>jakarta.persistence</groupId>
			<artifactId>jakarta.persistence-api</artifactId>
			<version>2.2.3</version>
		</dependency>
		<dependency>
			<groupId>jakarta.validation</groupId>
			<artifactId>jakarta.validation-api</artifactId>
			<version>2.0.2</version>
		</dependency>
		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-jpamodelgen</artifactId>
			<version>5.3.13.Final</version>
		</dependency>
		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-core</artifactId>
			<version>5.3.13.Final</version>

		</dependency>
		<dependency>
			<groupId>org.jboss.spec.javax.ejb</groupId>
			<artifactId>jboss-ejb-api_3.2_spec</artifactId>
			<version>2.0.0.Final</version>
		</dependency>

		<dependency>
			<groupId>org.codehaus.groovy</groupId>
			<artifactId>groovy</artifactId>
			<version>3.0.7</version>
		</dependency>

		<dependency>
			<groupId>org.codehaus.groovy</groupId>
			<artifactId>groovy-sql</artifactId>
			<version>3.0.7</version>
		</dependency>

	</dependencies>

	<build>

		<pluginManagement>
			<plugins>

				<plugin>
					<groupId>org.apache.maven.plugins</groupId>
					<artifactId>maven-ejb-plugin</artifactId>
					<version>3.0.1</version>
					<configuration>
						<!-- Tell Maven we are using EJB -->
						<ejbVersion>3.2</ejbVersion>
					</configuration>
				</plugin>
			</plugins>
		</pluginManagement>
		<plugins>


			<plugin>
				<groupId>org.bsc.maven</groupId>
				<artifactId>maven-processor-plugin</artifactId>
				<version>4.5-jdk8</version>
				<executions>
					<execution>
						<id>process</id>
						<goals>
							<goal>process</goal>
						</goals>
						<phase>generate-sources</phase>
						<configuration>
							<includes>
								<include>com/tura/jpa/domain/*.java</include>
							</includes>
						<addOutputDirectoryToCompilationSources>true</addOutputDirectoryToCompilationSources>
							<processors>
								<processor>org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor</processor>
							</processors>
						</configuration>
					</execution>
				</executions>
				<dependencies>
					<dependency>
						<groupId>org.hibernate</groupId>
						<artifactId>hibernate-jpamodelgen</artifactId>
						<version>5.3.13.Final</version>
					</dependency>
				</dependencies>
			</plugin>

			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<version>3.8.0</version>
				<configuration>
					<source>1.8</source>
					<target>1.8</target>
					<proc>none</proc>

					<verbose>true</verbose>

				</configuration>

			</plugin>

		</plugins>
	</build>

</project>
``