Use correct java home for causal cluster

Author: lutovich

driver/src/test/java/org/neo4j/driver/v1/util/Neo4jRunner.java

@@ -159,14 +159,7 @@ public void restartNeo4j(Neo4jSettings neo4jSettings) throws IOException
     private int runCommand( String... cmd ) throws IOException
     {
         ProcessBuilder pb = new ProcessBuilder().inheritIO();
-        Map<String,String> env = System.getenv();
-        pb.environment().put( "JAVA_HOME",
-                // This driver is built to work with multiple java versions.
-                // Neo4j, however, works with a specific version of Java. This allows
-                // specifying which Java version to use for Neo4j separately from which
-                // version to use for the driver tests.
-                env.containsKey( "NEO4J_JAVA" ) ? env.get( "NEO4J_JAVA" ) :
-                System.getProperties().getProperty( "java.home" ) );
+        ProcessEnvConfigurator.configure( pb );
         if( NEORUN_START_ARGS != null )
         {
             // overwrite the env var in the sub process if the system property is specified

driver/src/test/java/org/neo4j/driver/v1/util/ProcessEnvConfigurator.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2002-2016 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.neo4j.driver.v1.util;
+
+import java.util.Map;
+
+public final class ProcessEnvConfigurator
+{
+    /**
+     * Name of environment variable used by the Neo4j database.
+     */
+    private static final String JAVA_HOME = "JAVA_HOME";
+    /**
+     * Name of environment variable to be used for the Neo4j database, defined by the build system.
+     */
+    private static final String NEO4J_JAVA = "NEO4J_JAVA";
+
+    private ProcessEnvConfigurator()
+    {
+    }
+
+    public static void configure( ProcessBuilder processBuilder )
+    {
+        processBuilder.environment().put( JAVA_HOME, determineJavaHome() );
+    }
+
+    /**
+     * This driver is built to work with multiple java versions. Neo4j, however, works with a specific version of
+     * Java. This allows specifying which Java version to use for Neo4j separately from which version to use for
+     * the driver tests.
+     * <p>
+     * This method determines which java home to use based on present environment variables.
+     *
+     * @return path to the java home.
+     */
+    private static String determineJavaHome()
+    {
+        Map<String,String> environment = System.getenv();
+
+        String definedJava = environment.get( NEO4J_JAVA );
+        if ( definedJava != null )
+        {
+            return definedJava;
+        }
+
+        return System.getProperties().getProperty( "java.home" );
+    }
+}

driver/src/test/java/org/neo4j/driver/v1/util/cc/ClusterControl.java

@@ -25,6 +25,8 @@
 import java.nio.file.Path;
 import java.util.Arrays;
 
+import org.neo4j.driver.v1.util.ProcessEnvConfigurator;
+
 import static java.lang.System.lineSeparator;
 
 final class ClusterControl
@@ -75,6 +77,7 @@ private static String executeCommand( String... command )
         try
         {
             ProcessBuilder processBuilder = new ProcessBuilder().command( command );
+            ProcessEnvConfigurator.configure( processBuilder );
             return executeAndGetStdOut( processBuilder );
         }
         catch ( IOException e )