[java8API] SPARK-964 Investigate the potential for using JDK 8 lambda expressions for the Java/Scala APIs

Author: Prashant Sharma <prashant.s@imaginea.com>
Author: Patrick Wendell <pwendell@gmail.com>

Closes #17 from ScrapCodes/java8-lambdas and squashes the following commits:

95850e6 [Patrick Wendell] Some doc improvements and build changes to the Java 8 patch.
85a954e [Prashant Sharma] Nit. import orderings.
673f7ac [Prashant Sharma] Added support for -java-home as well
80a13e8 [Prashant Sharma] Used fake class tag syntax
26eb3f6 [Prashant Sharma] Patrick's comments on PR.
35d8d79 [Prashant Sharma] Specified java 8 building in the docs
31d4cd6 [Prashant Sharma] Maven build to support -Pjava8-tests flag.
4ab87d3 [Prashant Sharma] Review feedback on the pr
c33dc2c [Prashant Sharma] SPARK-964, Java 8 API Support.

1 files changed, 10 insertions, 0 deletions

diff --git a/dev/run-tests b/dev/run-tests
index d65a397b4c..cf0b940c09 100755
--- a/dev/run-tests
+++ b/dev/run-tests
@@ -27,6 +27,16 @@ rm -rf ./work
 # Fail fast
 set -e
 
+if test -x "$JAVA_HOME/bin/java"; then
+    declare java_cmd="$JAVA_HOME/bin/java"
+else 
+    declare java_cmd=java
+fi
+
+JAVA_VERSION=$($java_cmd -version 2>&1 | sed 's/java version "\(.*\)\.\(.*\)\..*"/\1\2/; 1q')
+[ "$JAVA_VERSION" -ge 18 ] && echo "" || echo "[Warn] Java 8 tests will not run, because JDK version is < 1.8."
+
+
 echo "========================================================================="
 echo "Running Scala style checks"
 echo "========================================================================="