Merge pull request #4010 from rgilles/master

Isolate the complied Java classes into a target folder.

tests/JavaTest.sh

-#!/bin/sh
+#!/bin/bash
 #
 # Copyright 2014 Google Inc. All rights reserved.
 #
@@ -16,14 +16,29 @@
 
 echo Compile then run the Java test.
 
+java -version
+
 testdir=$(readlink -fn `dirname $0`)
 thisdir=$(readlink -fn `pwd`)
 
+targetdir=${testdir}/target
+
 if [[ "$testdir" != "$thisdir" ]]; then
 	echo error: must be run from inside the ${testdir} directory
 	echo you ran it from ${thisdir}
 	exit 1
 fi
 
-javac -classpath ${testdir}/../java:${testdir}:${testdir}/namespace_test JavaTest.java
-java -classpath ${testdir}/../java:${testdir}:${testdir}/namespace_test JavaTest
+find .. -type f -name "*.class" -exec rm  {} \;
+
+if [[ -e "${targetdir}" ]]; then
+    echo "clean target"
+    rm -rf ${targetdir}
+fi
+
+mkdir ${targetdir}
+
+javac -d ${targetdir} -classpath ${testdir}/../java:${testdir}:${testdir}/namespace_test JavaTest.java
+java -classpath ${targetdir} JavaTest
+
+rm -rf ${targetdir}