[JHipster] mvnw 실행 시 'Some Enforcer rules have failed. Look above for specific messages explaining why the rule failed' 오류

증상

JHipster 가 어떤건지 한번 볼까 싶어 받아서 예제에 있는대로 하나하나 따라하는데 아래와 같이 나오며 구동을 못시키는 상황이 되었다.

C:\Users\1004lucifer\IdeaProjects\jhipster-example>mvnw
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building Jhipster 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] >>> spring-boot-maven-plugin:1.5.4.RELEASE:run (default-cli) > test-compile @ jhipster >>>
[INFO]
[INFO] --- maven-resources-plugin:3.0.1:copy-resources (default-resources) @ jhipster ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 6 resources
[INFO] Copying 14 resources
[INFO]
[INFO] --- maven-resources-plugin:3.0.1:resources (default-resources) @ jhipster ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 6 resources
[INFO] Copying 14 resources
[INFO]
[INFO] --- maven-enforcer-plugin:1.4.1:enforce (enforce-versions) @ jhipster ---
[WARNING] Rule 1: org.apache.maven.plugins.enforcer.RequireJavaVersion failed with message:
You are running an older version of Java. JHipster requires at least JDK 1.8
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 10.575 s
[INFO] Finished at: 2017-08-20T16:12:37+09:00
[INFO] Final Memory: 25M/161M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-enforcer-plugin:1.4.1:enforce (enforce-versions) on project jhipster: Some Enforcer rules have failed. Look above for specific messages explaining why the rule failed. -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

C:\Users\1004lucifer\IdeaProjects\jhipster-example>

원인

>mvnw --debug  디버그옵션을 켜고 다시 수행을 해보니 JDK 1.8 이상의 버전에서 수행해야 한다고 알려준다.

C:\Users\1004lucifer\IdeaProjects\jhipster-example>mvnw --debug
Apache Maven 3.5.0 (ff8f5e7444045639af65f6095c62210b5713f426; 2017-04-04T04:39:06+09:00)
Maven home: C:\Users\1004lucifer\.m2\wrapper\dists\apache-maven-3.5.0-bin\6ps54u5pnnbbpr6ds9rppcc7iv\apache-maven-3.5.0
Java version: 1.7.0_80, vendor: Oracle Corporation
Java home: C:\Program Files\Java\jdk1.7.0_80\jre
Default locale: ko_KR, platform encoding: MS949
OS name: "windows 8.1", version: "6.3", arch: "amd64", family: "windows"
[DEBUG] Created new class realm maven.api
[DEBUG] Importing foreign packages into class realm maven.api
[DEBUG]   Imported: javax.enterprise.inject.* < plexus.core

...

[DEBUG] Adding failure due to exception
org.apache.maven.enforcer.rule.api.EnforcerRuleException: You are running an older version of Java. JHipster requires at least JDK 1.8
        at org.apache.maven.plugins.enforcer.AbstractVersionEnforcer.enforceVersion(AbstractVersionEnforcer.java:106)
        at org.apache.maven.plugins.enforcer.RequireJavaVersion.execute(RequireJavaVersion.java:65)
        at org.apache.maven.plugins.enforcer.EnforceMojo.execute(EnforceMojo.java:193)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:154)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:146)
        at org.apache.maven.lifecycle.internal.MojoExecutor.executeForkedExecutions(MojoExecutor.java:353)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:198)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:154)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:146)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81)
        at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:309)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:194)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:107)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:993)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:345)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:191)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.apache.maven.wrapper.BootstrapMainStarter.start(BootstrapMainStarter.java:39)
        at org.apache.maven.wrapper.WrapperExecutor.execute(WrapperExecutor.java:122)
        at org.apache.maven.wrapper.MavenWrapperMain.main(MavenWrapperMain.java:50)
[WARNING] Rule 1: org.apache.maven.plugins.enforcer.RequireJavaVersion failed with message:
You are running an older version of Java. JHipster requires at least JDK 1.8
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE

[INFO] ------------------------------------------------------------------------

JDK1.8 설치 및 JAVA_HOME 환경변수까지 잡아준 후 다시 구동(>mvnw) 을 하니 정상적으로 수행이 되었다.