Java 9 question & issue

Are there any plans to support java 9, meaning that the generated bytecode should be compatible with java 9, right?

I’m asking this because I encountered an interesting issue:

I have a project lambdamatchers which has some lambdas based on Stream class, which I agree they are not supposed to work on Java < 8.

I run retrolambda on the classes and after I run unit tests using Java 8, it works fine with the code created by retrolambda (using as a target 1.5, 1.6, 1.7 and even 1.8), but when running the unit tests using Java 9 i get the IncompatibleClassChangeError:

java.lang.IncompatibleClassChangeError: Method java.util.stream.Stream.of([Ljava/lang/Object;)Ljava/util/stream/Stream; must be InterfaceMethodref constant
    at ro.derbederos.hamcrest.StreamTest.streamOf(StreamTest.java:32)
...

This can be easily reproduced with:

public class StreamTest {
    @Test
    public void streamIsEmpty() {
        Stream.empty();
    }
}

Stream::empty is a static interface method, maybe the way they are invoked is the issue.

Also, running unit tests with Java 9 without retrolambda-ing the project does not reproduce the issue. I’m not 100% sure, but this might to be an issue with the jvm.

Note: This is not a real issue, I observed it during some tests, but I can work around it, as only the test code had issues, but I wanted to bring it into attention. Hopefully this does not cause problems for anybody. The test code in my case can be read as “the client code” and the client should not use retrolambda if the target is Java >= 8.

[luontola]

Hmm, now that I look at the stack trace more closely, it’s coming from Retrolambda’s code (it’s the commandline parsing which happens before your code is even loaded). Please create a new issue. Preferrably with a sample project for reproducing the issue (http://sscce.org/).

[MastaP]

Fails with [ERROR] Failed to execute goal net.orfjackal.retrolambda:retrolambda-maven-plugin:2.5.1:process-main (default) on project xhub-mappings: Unable to execute mojo: An Ant BuildException has occured: exec returned: 1 [ERROR] around Ant part ...<exec failonerror="true" executable="/Library/Java/JavaVirtualMachines/jdk1.8.0_111.jdk/Contents/Home/bin/java">... @ 4:115 in /Users/pavelg/zt/pacman/xhub-agent/xhub-mappings/target/antrun/build-main.xml [ERROR] -> [Help 1] org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal net.orfjackal.retrolambda:retrolambda-maven-plugin:2.5.1:process-main (default) on project xhub-mappings: Unable to execute mojo at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212) ... Caused by: org.apache.maven.plugin.MojoExecutionException: Unable to execute mojo at org.twdata.maven.mojoexecutor.MojoExecutor.executeMojo(MojoExecutor.java:96) at net.orfjackal.retrolambda.maven.ProcessClassesMojo.processClassesInForkedProcess(ProcessClassesMojo.java:158) at net.orfjackal.retrolambda.maven.ProcessClassesMojo.execute(ProcessClassesMojo.java:112) at net.orfjackal.retrolambda.maven.ProcessMainClassesMojo.execute(ProcessMainClassesMojo.java:17) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)

also, specifying java8home on all environments is not convenient. I’ll try to come up with SSCCE later, if still needed