Refactor SparkClient constructors (#1318)

add overloads that accept a zFactoryClassName string.

Author: padam-prakash

.gitignore

@@ -31,3 +31,4 @@ assembly/dependency-reduced-pom.xml
 
 # Sphinx _build
 **/_build
+/python/venv

spark/client/src/main/java/zingg/spark/client/SparkClient.java

@@ -30,22 +30,35 @@ public class SparkClient extends Client<SparkSession, Dataset<Row>, Row, Column,
 	private JavaSparkContext javaSparkContext;
 
 	public SparkClient(IZArgs args, ClientOptions options) throws ZinggClientException {
-		super(args, options, zFactoryClassName);
-		
+		this(args, options, zFactoryClassName);
 	}
 
 
 	public SparkClient(IZArgs args, ClientOptions options, SparkSession s) throws ZinggClientException {
-		super(args, options, s, zFactoryClassName);
-		Analytics.track(Metric.IS_PYTHON, "true", args.getCollectMetrics());
+		this(args, options, s, zFactoryClassName);
 	}
 
 
 	public SparkClient() {
-		super(zFactoryClassName);
+		this(zFactoryClassName);
+	}
+
+	public SparkClient(IZArgs args, ClientOptions options, String zFactoryClassName) throws ZinggClientException {
+		super(args, options, zFactoryClassName);
+
 	}
 
 
+	public SparkClient(IZArgs args, ClientOptions options, SparkSession s, String zFactoryClassName) throws ZinggClientException {
+		super(args, options, s, zFactoryClassName);
+		Analytics.track(Metric.IS_PYTHON, "true", args.getCollectMetrics());
+	}
+
+
+	public SparkClient(String zFactoryClassName) {
+		super(zFactoryClassName);
+	}
+
 	@Override
 	public Client<SparkSession, Dataset<Row>, Row, Column, DataType> getClient(IZArgs args, 
 		ClientOptions options) throws ZinggClientException {