From af2ab98574582099557932e6a6370bf8dcdf3fab Mon Sep 17 00:00:00 2001
From: Shankeerthan Kasilingam
 <33720251+shankeerthan-kasilingam@users.noreply.github.com>
Date: Sat, 26 Jun 2021 05:26:34 +0530
Subject: [PATCH] Use ExecutorService variables to assign ExecutorService
 Instances (#11373)

* Added inspection rule to prohibit ExecutorService assignment to Executor

* Use ExecutorService type variable to assign ExecutorService

* Changed : Variable => variable

* Removed unused Executor import
---
 .idea/inspectionProfiles/Druid.xml                     | 10 ++++++++++
 .../druid/security/kerberos/KerberosHttpClient.java    |  4 ++--
 .../apache/druid/server/initialization/JettyTest.java  |  4 ++--
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/.idea/inspectionProfiles/Druid.xml b/.idea/inspectionProfiles/Druid.xml
index 2da1cb7f2e1..d1f72dd2763 100644
--- a/.idea/inspectionProfiles/Druid.xml
+++ b/.idea/inspectionProfiles/Druid.xml
@@ -372,6 +372,16 @@
         <constraint name="l" within="" contains="" />
         <constraint name="y" minCount="0" maxCount="2147483647" within="" contains="" />
       </searchConfiguration>
+      <searchConfiguration name="Assign an ExecutorService instance to an ExecutorService variable, not an Executor variable" text="$x$ = $y$;" recursive="true" caseInsensitive="true" type="JAVA" >
+        <constraint name="__context__" within="" contains="" />
+        <constraint name="x" nameOfExprType="java\.util\.concurrent\.Executor" within="" contains="" />
+        <constraint name="y" nameOfExprType="java\.util\.concurrent\.ExecutorService" exprTypeWithinHierarchy="true" within="" contains="" />
+      </searchConfiguration>
+      <searchConfiguration name="Intialize an ExecutorService instance to an ExecutorService variable, not an Executor variable" text="Executor $x$ = $y$;" recursive="true" caseInsensitive="true" type="JAVA" >
+        <constraint name="__context__" within="" contains="" />
+        <constraint name="x"  within="" contains="" />
+        <constraint name="y" nameOfExprType="java\.util\.concurrent\.ExecutorService" exprTypeWithinHierarchy="true"  within="" contains="" />
+      </searchConfiguration>
       <searchConfiguration name="Create a simple ExecutorService (not scheduled)" text="$x$ = $y$;" recursive="true" caseInsensitive="true" type="JAVA" pattern_context="default">
         <constraint name="__context__" within="" contains="" />
         <constraint name="x" nameOfExprType="java\.util\.concurrent\.ExecutorService" within="" contains="" />
diff --git a/extensions-core/druid-kerberos/src/main/java/org/apache/druid/security/kerberos/KerberosHttpClient.java b/extensions-core/druid-kerberos/src/main/java/org/apache/druid/security/kerberos/KerberosHttpClient.java
index 6a7e69336f7..eee32ac44e2 100644
--- a/extensions-core/druid-kerberos/src/main/java/org/apache/druid/security/kerberos/KerberosHttpClient.java
+++ b/extensions-core/druid-kerberos/src/main/java/org/apache/druid/security/kerberos/KerberosHttpClient.java
@@ -39,7 +39,7 @@ import java.security.PrivilegedExceptionAction;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorService;
 
 public class KerberosHttpClient extends AbstractHttpClient
 {
@@ -47,7 +47,7 @@ public class KerberosHttpClient extends AbstractHttpClient
 
   private final HttpClient delegate;
   private final CookieManager cookieManager;
-  private final Executor exec = Execs.singleThreaded("test-%s");
+  private final ExecutorService exec = Execs.singleThreaded("test-%s");
   private final String internalClientPrincipal;
   private final String internalClientKeytab;
 
diff --git a/server/src/test/java/org/apache/druid/server/initialization/JettyTest.java b/server/src/test/java/org/apache/druid/server/initialization/JettyTest.java
index 0e7459b9d13..1e8f36924d5 100644
--- a/server/src/test/java/org/apache/druid/server/initialization/JettyTest.java
+++ b/server/src/test/java/org/apache/druid/server/initialization/JettyTest.java
@@ -76,7 +76,7 @@ import java.util.EnumSet;
 import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeUnit;
@@ -268,7 +268,7 @@ public class JettyTest extends BaseJettyTest
   public void testTimeouts() throws Exception
   {
     // test for request timeouts properly not locking up all threads
-    final Executor executor = Executors.newFixedThreadPool(100);
+    final ExecutorService executor = Executors.newFixedThreadPool(100);
     final AtomicLong count = new AtomicLong(0);
     final CountDownLatch latch = new CountDownLatch(1000);
     for (int i = 0; i < 10000; i++) {