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https://issues.apache.org/jira/browse/MNG-5756?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14948935#comment-14948935
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Jarkko Rantavuori commented on MNG-5756:
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{quote}System.getProperty( "java.home", "<unknown java home>" ) this is
correct. Though it is confusing.{quote}
Well, I just don't agree. Maven shouldn't be saying things about "java home" or
"Java home" when it is actually referring to "java.home". I don't think you
disagree about the statement that normally when anybody in java ecosystem is
talking about java home, they refer to JAVA_HOME environment setting. Given
that, if output of a program is meaning something else with it, it would be the
fault of that program - in this case Maven. This has been evident with tens of
users tripping on this on stackoverflow.
{quote}JAVA_HOME != java.home.{quote}
Yes. And {noformat}java.home{noformat} != {noformat}java home{noformat}. But
"java home", if that term is to be used, really should refer to JAVA_HOME.
> Java home output in mvn -v is misleading
> ----------------------------------------
>
> Key: MNG-5756
> URL: https://issues.apache.org/jira/browse/MNG-5756
> Project: Maven
> Issue Type: Improvement
> Components: Command Line
> Affects Versions: 3.2.5, 3.3.3
> Environment: any
> Reporter: Jarkko Rantavuori
> Priority: Minor
>
> For example on my windows box, mvn -v prints the following:
> {code}
> Java home: C:\Program Files (x86)\Java\jdk1.7.0_51\jre
> {code}
> But my JAVA_HOME is actually
> {code}
> > echo %JAVA_HOME%
> C:\Program Files (x86)\Java\jdk1.7.0_51
> {code}
> In the source code, the line comes from:
> https://git-wip-us.apache.org/repos/asf?p=maven.git;a=blob;f=maven-embedder/src/main/java/org/apache/maven/cli/CLIReportingUtils.java#l63
> {code}
> version.append( "Java home: " ).append( System.getProperty( "java.home",
> "<unknown java home>" ) ).append( ls );
> {code}
> which is using property "java.home" to fetch java home. However, "java.home"
> property is not JAVA_HOME! This is explained in detail in here:
> http://javahowto.blogspot.fi/2006/05/javahome-vs-javahome.html
> To quote:
> {quote}
> What's the difference between JAVA_HOME and java.home?
> JAVA_HOME is the JDK install directory, e.g., C:\jdk5. It's meant to be
> set as an environment variable and referenced in Windows batch files or Unix
> scripts. I always have it in my Windows Control Panel and .tcsh files,along
> with other common environment variables. Some Java applications use the name
> jdk.home for this purpose, which I think is a better name. But JAVA_HOME has
> been used since the beginning and is now a convention.
> java.home is the JRE install directory, e.g., C:\jdk5\jre, or C:\Program
> Files\Java\jre1.5.0_06. Unlike JAVA_HOME, I never seen java.home as an
> environment variable. java.home is a build-in Java system property, whose
> value is the JRE install directory. Since all Java system properties are also
> exposed as Ant build properties, you can also use ${java.home} in
> build files.
> Would jre.home be a better name? Maybe, but I don't think Sun will change
> it.
> {quote}
> This is a source of constant confusion. Some stackoverflow threads to
> illustrate:
> http://stackoverflow.com/questions/15279586/java-home-in-maven
> http://stackoverflow.com/questions/17620531/maven-pointing-to-jre-instead-of-jdk
> The correct way to print JAVA_HOME would be to use
> System.getenv("JAVA_HOME"). Either that should be used or current output
> should be changed so it wouldn't be so misleading.
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