Move buildCommand part under exception handling

Author: gaborgsomogyi

launcher/src/main/java/org/apache/spark/launcher/Main.java

@@ -17,6 +17,7 @@
 
 package org.apache.spark.launcher;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -54,10 +55,12 @@ public static void main(String[] argsArray) throws Exception {
     String className = args.remove(0);
 
     boolean printLaunchCommand = !isEmpty(System.getenv("SPARK_PRINT_LAUNCH_COMMAND"));
-    AbstractCommandBuilder builder;
+    Map<String, String> env = new HashMap<>();
+    List<String> cmd;
     if (className.equals("org.apache.spark.deploy.SparkSubmit")) {
       try {
-        builder = new SparkSubmitCommandBuilder(args);
+        AbstractCommandBuilder builder = new SparkSubmitCommandBuilder(args);
+        cmd = buildCommand(builder, env, printLaunchCommand);
       } catch (IllegalArgumentException e) {
         printLaunchCommand = false;
         System.err.println("Error: " + e.getMessage());
@@ -76,17 +79,12 @@ public static void main(String[] argsArray) throws Exception {
           help.add(parser.className);
         }
         help.add(parser.USAGE_ERROR);
-        builder = new SparkSubmitCommandBuilder(help);
+        AbstractCommandBuilder builder = new SparkSubmitCommandBuilder(help);
+        cmd = buildCommand(builder, env, printLaunchCommand);
       }
     } else {
-      builder = new SparkClassCommandBuilder(className, args);
-    }
-
-    Map<String, String> env = new HashMap<>();
-    List<String> cmd = builder.buildCommand(env);
-    if (printLaunchCommand) {
-      System.err.println("Spark Command: " + join(" ", cmd));
-      System.err.println("========================================");
+      AbstractCommandBuilder builder = new SparkClassCommandBuilder(className, args);
+      cmd = buildCommand(builder, env, printLaunchCommand);
     }
 
     if (isWindows()) {
@@ -101,6 +99,22 @@ public static void main(String[] argsArray) throws Exception {
     }
   }
 
+  /**
+   * Prepare spark commands with the appropriate command builder.
+   * If printLaunchCommand is set then the commands will be printed to the stderr.
+   */
+  private static List<String> buildCommand(AbstractCommandBuilder builder,
+                                           Map<String, String> env,
+                                           boolean printLaunchCommand)
+    throws IOException, IllegalArgumentException {
+    List<String> cmd = builder.buildCommand(env);
+    if (printLaunchCommand) {
+      System.err.println("Spark Command: " + join(" ", cmd));
+      System.err.println("========================================");
+    }
+    return cmd;
+  }
+
   /**
    * Prepare a command line for execution from a Windows batch script.
    *

launcher/src/main/java/org/apache/spark/launcher/SparkSubmitCommandBuilder.java

@@ -139,10 +139,8 @@ class SparkSubmitCommandBuilder extends AbstractCommandBuilder {
 
         case RUN_EXAMPLE:
           isExample = true;
+          appResource = SparkLauncher.NO_RESOURCE;
           submitArgs = args.subList(1, args.size());
-          if (submitArgs.isEmpty()) {
-            throw new IllegalArgumentException("Missing argument");
-          }
       }
 
       this.isExample = isExample;
@@ -151,7 +149,7 @@ class SparkSubmitCommandBuilder extends AbstractCommandBuilder {
         parser.parse(submitArgs);
         this.isSpecialCommand = parser.isSpecialCommand;
       } else {
-        this.isSpecialCommand = true;
+        this.isSpecialCommand = false;
       }
     } else {
       this.isExample = isExample;

launcher/src/test/java/org/apache/spark/launcher/SparkSubmitCommandBuilderSuite.java

@@ -28,7 +28,10 @@
 
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
 import static org.junit.Assert.*;
 
 public class SparkSubmitCommandBuilderSuite extends BaseSuite {
@@ -208,6 +211,22 @@ public void testExamplesRunnerNoMainClass() throws Exception {
     testCLIOpts(SparkSubmitCommandBuilder.RUN_EXAMPLE, parser.VERSION, null);
   }
 
+  @Rule
+  public ExpectedException testExamplesRunnerWithMasterNoMainClassEx = ExpectedException.none();
+
+  @Test
+  public void testExamplesRunnerWithMasterNoMainClass() throws Exception {
+    testExamplesRunnerWithMasterNoMainClassEx.expect(IllegalArgumentException.class);
+    testExamplesRunnerWithMasterNoMainClassEx.expectMessage("Missing example class name.");
+
+    List<String> sparkSubmitArgs = Arrays.asList(
+      SparkSubmitCommandBuilder.RUN_EXAMPLE,
+      parser.MASTER + "=foo"
+    );
+    Map<String, String> env = new HashMap<>();
+    buildCommand(sparkSubmitArgs, env);
+  }
+
   @Test
   public void testExamplesRunner() throws Exception {
     List<String> sparkSubmitArgs = Arrays.asList(