[SPARK-11094] Strip extra strings from Java version in test runner

Removes any extra strings from the Java version, fixing subsequent integer parsing.
This is required since some OpenJDK versions (specifically in Debian testing), append an extra "-internal" string to the version field.

Author: Jakob Odersky <jodersky@gmail.com>

Closes #9111 from jodersky/fixtestrunner.

dev/run-tests.py

@@ -176,17 +176,14 @@ def determine_java_version(java_exe):
     # find raw version string, eg 'java version "1.8.0_25"'
     raw_version_str = next(x for x in raw_output_lines if " version " in x)
 
-    version_str = raw_version_str.split()[-1].strip('"')  # eg '1.8.0_25'
-    version, update = version_str.split('_')  # eg ['1.8.0', '25']
+    match = re.search('(\d+)\.(\d+)\.(\d+)_(\d+)', raw_version_str)
 
-    # map over the values and convert them to integers
-    version_info = [int(x) for x in version.split('.') + [update]]
-
-    return JavaVersion(major=version_info[0],
-                       minor=version_info[1],
-                       patch=version_info[2],
-                       update=version_info[3])
+    major = int(match.group(1))
+    minor = int(match.group(2))
+    patch = int(match.group(3))
+    update = int(match.group(4))
 
+    return JavaVersion(major, minor, patch, update)
 
 # -------------------------------------------------------------------------------------------------
 # Functions for running the other build and test scripts