./gradlew install fails with UnsupportedClassVersionError

[pdkovacs]

Summary

./gradlew install fails with java.lang.UnsupportedClassVersionError

Actual Behavior

1. Check (as per https://github.com/spring-projects/spring-security/blob/master/README.adoc#prerequisites) that the JAVA_HOME environment variable points to Oracle JDK 7:

$ $JAVA_HOME/bin/java -version
Picked up JAVA_TOOL_OPTIONS: -Djava.awt.headless=true
java version "1.7.0_80"
Java(TM) SE Runtime Environment (build 1.7.0_80-b15)
Java HotSpot(TM) 64-Bit Server VM (build 24.80-b11, mixed mode)

2. Check out sources (as per https://github.com/spring-projects/spring-security/blob/master/README.adoc#check-out-sources):

$ git clone git@github.com:spring-projects/spring-security.git
Cloning into 'spring-security'...
remote: Counting objects: 127438, done.
remote: Compressing objects: 100% (16/16), done.
remote: Total 127438 (delta 1), reused 0 (delta 0), pack-reused 127419
Receiving objects: 100% (127438/127438), 24.99 MiB | 939.00 KiB/s, done.
Resolving deltas: 100% (61511/61511), done.

3. Change the current working directory to the root of the source tree (as per https://github.com/spring-projects/spring-security/blob/master/README.adoc#building-from-source):

$ cd spring-security/

4. Execute ./gradlew install (as per https://github.com/spring-projects/spring-security/blob/master/README.adoc#install-all-spring--jars-into-your-local-maven-cache):

$ ./gradlew install
Picked up JAVA_TOOL_OPTIONS: -Djava.awt.headless=true
:buildSrc:clean UP-TO-DATE
:buildSrc:compileJava UP-TO-DATE
:buildSrc:compileGroovy
Picked up JAVA_TOOL_OPTIONS: -Djava.awt.headless=true
:buildSrc:processResources
:buildSrc:classes
:buildSrc:jar
:buildSrc:assemble
:buildSrc:compileTestJava UP-TO-DATE
:buildSrc:compileTestGroovy UP-TO-DATE
:buildSrc:processTestResources UP-TO-DATE
:buildSrc:testClasses UP-TO-DATE
:buildSrc:test UP-TO-DATE
:buildSrc:check UP-TO-DATE
:buildSrc:build

FAILURE: Build failed with an exception.

* What went wrong:
java.lang.UnsupportedClassVersionError: org/sonarqube/gradle/SonarQubePlugin : Unsupported major.minor version 52.0
> org/sonarqube/gradle/SonarQubePlugin : Unsupported major.minor version 52.0

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 6.401 secs

Expected Behavior

I expect the command to complete without errors with a successful status (BUILD SUCCESS)

Configuration

I am not sure what else beyond the Prerequisites might be relevant here. (Maybe the git version:

$ git --version
git version 2.10.0

)

Version

It is a fresh clone.

Sample

[pdkovacs]

The sonarqube version was upped in commit 81ebdecd8a6b from 1.2 to 2.1.-rc1. With sonarqube version 1.2, the command ./gradlew install completes successfully. (I've got a lot of [options] bootstrap class path not set in conjunction with -source 1.6 warnings, though.)

The most authoritative description about SonarQube I've found is for version 2.2 and says directly nothing about the Java version required: http://docs.sonarqube.org/display/SCAN/Analyzing+with+SonarQube+Scanner+for+Gradle#AnalyzingwithSonarQubeScannerforGradle-Compatibility .

The page for the sonarqube gradle plugin says nothing about required Java version, but says that it is compatible with SonarQube versions 4.5+.

As for SonarQube itself:

Of course, we’ll still support running older versions of ecosystem products, e.g. SonarQube 4.5, with Java 7, and you’ll still be able to compile your project with a lower version of Java. You’ll just have to bump up the JVM version to run the analysis.

The sonarqube gradle plugin source tree for 2.1-rc1 includes this change which leads me to think that 2.1-rc1 requires Java 8.

By the by, is the following in the Spring Security FAQ still true:

Spring Security 3.0 and 3.1 require at least JDK 1.5 and also require Spring 3.0.3 as a minimum.

? If it is, shouldn't the thing be built with JDK 5 (instead of JDK 7 as is stated in the Prerequisites)?