added singleton SparkSessionProvider

Author: Nitish1814

spark/core/src/test/java/zingg/session/SparkSessionProvider.java

@@ -0,0 +1,73 @@
+package zingg.session;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.SparkSession;
+import zingg.common.client.Arguments;
+import zingg.common.client.IArguments;
+import zingg.common.client.IZingg;
+import zingg.spark.core.context.ZinggSparkContext;
+
+public class SparkSessionProvider {
+
+    private static SparkSessionProvider sparkSessionProvider;
+
+    private SparkSession sparkSession;
+    private JavaSparkContext javaSparkContext;
+    private ZinggSparkContext zinggSparkContext;
+    private IArguments args;
+    public static final Log LOG = LogFactory.getLog(SparkSessionProvider.class);
+
+    private void initializeSession() {
+        if (sparkSession == null) {
+            try {
+                sparkSession = SparkSession
+                        .builder()
+                        .master("local[*]")
+                        .appName("ZinggJunit")
+                        .config("spark.debug.maxToStringFields", 100)
+                        .getOrCreate();
+                javaSparkContext = new JavaSparkContext(sparkSession.sparkContext());
+                JavaSparkContext.jarOfClass(IZingg.class);
+                javaSparkContext.setCheckpointDir("/tmp/checkpoint");
+                args = new Arguments();
+                zinggSparkContext = new ZinggSparkContext();
+                zinggSparkContext.init(sparkSession);
+            } catch (Throwable e) {
+                if (LOG.isDebugEnabled())
+                    e.printStackTrace();
+                LOG.info("Problem in spark env setup");
+            }
+        } else {
+            LOG.info("Spark session already active, ignoring create spark session!");
+        }
+    }
+
+    public static SparkSessionProvider getInstance() {
+        if (sparkSessionProvider == null) {
+            sparkSessionProvider = new SparkSessionProvider();
+            sparkSessionProvider.initializeSession();
+        }
+        return sparkSessionProvider;
+    }
+
+
+
+    //set getters
+    public SparkSession getSparkSession() {
+        return this.sparkSession;
+    }
+
+    public JavaSparkContext getJavaSparkContext() {
+        return this.javaSparkContext;
+    }
+
+    public ZinggSparkContext getZinggSparkContext() {
+        return this.zinggSparkContext;
+    }
+
+    public IArguments getArgs() {
+        return this.args;
+    }
+}

spark/core/src/test/java/zingg/spark/core/executor/TestSparkExecutors.java

@@ -21,6 +21,7 @@
 import zingg.common.core.executor.TrainMatcher;
 import zingg.common.core.executor.Trainer;
 import zingg.common.core.executor.TrainerValidator;
+import zingg.session.SparkSessionProvider;
 import zingg.spark.core.context.ZinggSparkContext;
 
 public class TestSparkExecutors extends TestExecutorsGeneric<SparkSession,Dataset<Row>,Row,Column,DataType> {
@@ -35,21 +36,11 @@ public class TestSparkExecutors extends TestExecutorsGeneric<SparkSession,Datase
 
 	protected ZinggSparkContext ctx;
 
-	public TestSparkExecutors() throws IOException, ZinggClientException {	
-		SparkSession spark = SparkSession
-				.builder()
-				.master("local[*]")
-				.appName("Zingg" + "Junit")
-				.getOrCreate();
-		
-		JavaSparkContext ctx1 = new JavaSparkContext(spark.sparkContext());
-    	JavaSparkContext.jarOfClass(IZingg.class);    
-		ctx1.setCheckpointDir("/tmp/checkpoint");
-
-		this.ctx = new ZinggSparkContext();
-		this.ctx.setSession(spark);
-		this.ctx.setUtils();
-		init(spark);
+	public TestSparkExecutors() throws IOException, ZinggClientException {
+		SparkSessionProvider sparkSessionProvider = SparkSessionProvider.getInstance();
+		ctx = sparkSessionProvider.getZinggSparkContext();
+		ctx.setSession(sparkSessionProvider.getSparkSession());
+		init(sparkSessionProvider.getSparkSession());
 	}
 
 	@Override

spark/core/src/test/java/zingg/spark/core/executor/ZinggSparkTester.java

@@ -21,6 +21,7 @@
 import zingg.common.client.IArguments;
 import zingg.common.client.IZingg;
 
+import zingg.session.SparkSessionProvider;
 import zingg.spark.core.context.ZinggSparkContext;
 
 public class ZinggSparkTester {
@@ -37,33 +38,11 @@ public class ZinggSparkTester {
 
     @BeforeAll
     public static void setup() {
-    	try {
-    		spark = SparkSession
-    				.builder()
-    				.master("local[*]")
-    				.appName("ZinggJunit")
-					.config("spark.debug.maxToStringFields", 100)
-    				.getOrCreate();
-    		ctx = new JavaSparkContext(spark.sparkContext());
-    		JavaSparkContext.jarOfClass(IZingg.class);    
-			ctx.setCheckpointDir("/tmp/checkpoint");
-			args = new Arguments();
-			zsCTX = new ZinggSparkContext();
-			zsCTX.init(spark);
-    	} catch (Throwable e) {
-    		if (LOG.isDebugEnabled())
-    			e.printStackTrace();
-    		LOG.info("Problem in spark env setup");
-    	}
-    }
-
-    @AfterAll
-    public static void teardown() {
-    	if (ctx != null)
-    		ctx.stop();
-
-    	if (spark != null)
-    		spark.stop();
+		SparkSessionProvider sparkSessionProvider = SparkSessionProvider.getInstance();
+		spark = sparkSessionProvider.getSparkSession();
+		ctx = sparkSessionProvider.getJavaSparkContext();
+		args = sparkSessionProvider.getArgs();
+		zsCTX = sparkSessionProvider.getZinggSparkContext();
     }
 
 	public Dataset<Row> createDFWithDoubles(int numRows, int numCols) {