Java 9 support

[vietj]

No description provided.

[bsorrentino]

Take a look to #64

[vietj]

will have a try and report :-)

[bsorrentino]

Thanks for support ;-)

[beikov]

Forking as needed to specify custom compiler options seems to work, but the options aren't passed properly yet. See #70 for a fix

[beikov]

It should work now, but I haven't been able to get javac(build 9+181) to do the right thing yet. Investigating right now..

[bsorrentino]

hug! .. I've just now released 3.3.2 with your pull

[beikov]

Well, according to the Javac documentation, it should already be working.. I guess they maybe introduced another regression or I am simply not seeing the problem...

[bsorrentino]

Really your fix has been to bypass the option.startsWith("-A") check to add custom compiler option (javacConf.addCompilerCustomArgument(option, "")).

Do you think that this could have affect the processor ?

The -A prefix is requested by javac specification

[beikov]

This should be safe. I also managed to get the processing work with JDK9 but now I think I'm facing a different problem(need to set addCompileSourceRoots for compilation to work). This issue can be closed I guess. I am going to investigate the new issue I have and open a new issue if necessary. To use a processor with JDK9 you need a configuration like

<plugin>
	<groupId>org.bsc.maven</groupId>
	<artifactId>maven-processor-plugin</artifactId>
	<executions>
		<execution>
			<id>process</id>
			<goals>
				<goal>process</goal>
			</goals>
			<phase>generate-sources</phase>
			<configuration>
				<fork>true</fork>
				<!-- Not sure why I need this flag to be set -->
				<addCompileSourceRoots>true</addCompileSourceRoots>
				<compilerArguments>--add-modules=java.se.ee -J--add-modules=java.se.ee</compilerArguments>
				<!-- source output directory -->
				<outputDirectory>${project.build.directory}/metamodel</outputDirectory>
				<processors>
					<processor>org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor</processor>
				</processors>
			</configuration>
		</execution>
	</executions>
	<dependencies>
		<!-- Metamodel -->
		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-jpamodelgen</artifactId>
			<version>1.3.0.Final</version>
		</dependency>
	</dependencies>
</plugin>

[bsorrentino]

thanks again for contribution

[plevart]

Hi, I'm trying to run the plugin with JDK 9 as proposed above, but it gives me the following error:

[INFO] --- maven-processor-plugin:3.3.2:process (process) @ tt-server ---
...
...
[DEBUG] Source directory: /home/peter/work/git/thinktime/tt-server/target/metamodel added
[DEBUG] processing source directory [/home/peter/work/git/thinktime/tt-server/target/metamodel]
[DEBUG] processing source directory [/home/peter/work/git/thinktime/tt-server/src/main/java]
[DEBUG] Adding compiler arg: --add-modules=java.se.ee
[DEBUG] Adding compiler arg: -J--add-modules=java.se.ee
[DEBUG] javac option: -cp
[DEBUG] javac option: ......
[DEBUG] javac option: -sourcepath
[DEBUG] javac option: /home/peter/work/git/thinktime/tt-server/src/main/java:/home/peter/work/git/thinktime/tt-server/target/metamodel
[DEBUG] javac option: -proc:only
[DEBUG] javac option: --add-modules=java.se.ee
[DEBUG] javac option: -J--add-modules=java.se.ee
[DEBUG] javac option: -processor
[DEBUG] javac option: org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor
[DEBUG] javac option: -d
[DEBUG] javac option: /home/peter/work/git/thinktime/tt-server/target/classes
[DEBUG] javac option: -s
[DEBUG] javac option: /home/peter/work/git/thinktime/tt-server/target/metamodel
[DEBUG] PROCESSOR COMPILER FORKED!
warning: [options] bootstrap class path not set in conjunction with -source 1.7
javac: option --add-modules not allowed with target 1.7

I'm not adding any -source and/or -target options. Where does javac get -source 1.7 - target 1.7 ?

[bsorrentino]

the plugin use the following strategy:

if exists project property maven.processor.target use it
else if exists project property maven.compiler.target use it
else use 1.7

[plevart]

Thanks. I found out that specifying <compilerArguments>-source 9 -target 9</compilerArguments> also overrides default 1.7 (perhaps because javac takes the later options and ignores the earlier). But I can not specify <compilerArguments>-release 9</compilerArguments> or maybe <compilerArguments>-release 8</compilerArguments> when compiling with JDK 9, because -release option can not be combined with default -source / -target given by plugin. There's no way to instruct the plugin to leave-out default -source / -target options, is it? Would it make sense for plugin to do that if maven.processor.target was defined to be an empty string?

[bsorrentino]

I guess that the simplest solution is to set in the project properties

<properties>
    <maven.compiler.source>1.9</maven.compiler.source>
    <maven.compiler.target>1.9</maven.compiler.target>
</properties>

as explained here

let me know if it works ... I never dealt with option -release until now

[plevart]

When I set -source 8 / -target 8 on JDK 9, I don't get the same effect as when I set -release 8, because -release 8 also instructs javac to compile with Java 8 APIs only (like specifying --bootclasspath $JDK8_HOME/rt.jar with JDK 8 javac). This is important to be able to run with java 8. I want to compile with JDK 9 because I create java modules for most maven modules. Only a few maven modules become Java 8 compatible jars for consuming in other projects...

[plevart]

maven-compiler-plugin 3.7.0 also supports <release>xxx</release> configuration element, but I don't know which property (if any) this sets. (maybe maven.compiler.release?). If this is true, you could detect that and pass -release option to javac instead of -source / -target. You could even have your own maven.processor.release option. What do you think?

[bsorrentino]

ok this is a new implementation, at now it is not supported

please cloud create a new issue in order that I can arrange its implementation?

note

Meanwhile can you try disabling fork compilation? <fork>false</fork>

[bsorrentino]

Released version 3.3.3-SNAPSHOT with new <release> configuration

@plevart please, test it and let me know if works