8071588: The spec for javax.script.ScriptEngineFactory.getProgram() should specify NPEs thrown

Reviewed-by: alanb, hannesw

jdk/src/java.scripting/share/classes/javax/script/ScriptEngineFactory.java

@@ -216,8 +216,9 @@ public interface ScriptEngineFactory {
      *  @param statements The statements to be executed.  May be return values of
      *  calls to the <code>getMethodCallSyntax</code> and <code>getOutputStatement</code> methods.
      *  @return The Program
+     *
+     *  @throws NullPointerException if the <code>statements</code> array or any of its elements is null
      */
-
     public String getProgram(String... statements);
 
     /**

jdk/test/javax/script/DummyScriptEngineFactory.java

@@ -91,9 +91,10 @@ public class DummyScriptEngineFactory implements ScriptEngineFactory {
     }
 
     public String getProgram(String... statements) {
+        Objects.requireNonNull(statements);
         StringBuffer buf = new StringBuffer();
-        for (int i = 0; i < statements.length; i++) {
-            buf.append(statements[i]);
+        for (String stat : statements) {
+            buf.append(Objects.requireNonNull(stat));
         }
         return buf.toString();
     }