GEODE-8882: Enable JetBrains NotNull Annotation (apache#5967)

* Enable JetBrains NotNull Annotation in geode-core
* fix NPE bug introduced in fix for GEODE-8870

boms/geode-all-bom/src/test/resources/expected-pom.xml

@@ -877,6 +877,12 @@
         <version>2.4.1</version>
         <scope>compile</scope>
       </dependency>
+      <dependency>
+        <groupId>org.jetbrains</groupId>
+        <artifactId>annotations</artifactId>
+        <version>20.1.0</version>
+        <scope>compile</scope>
+      </dependency>
       <dependency>
         <groupId>org.apache.geode</groupId>
         <artifactId>geode-common</artifactId>

buildSrc/src/main/groovy/org/apache/geode/gradle/plugins/DependencyConstraints.groovy

@@ -272,5 +272,10 @@ class DependencyConstraints implements Plugin<Project> {
     dependencySet(group: 'org.springframework.session', version: '2.4.1') {
       entry('spring-session-data-redis')
     }
+
+    dependencySet(group: 'org.jetbrains', version: '20.1.0') {
+      entry('annotations')
+    }
+
   }
 }

geode-common/build.gradle

@@ -26,7 +26,6 @@ dependencies {
   implementation(platform(project(':boms:geode-all-bom')))
   implementation('com.fasterxml.jackson.core:jackson-databind')
 
-
   // test
   testImplementation('junit:junit')
   testImplementation('org.assertj:assertj-core')

geode-core/build.gradle

@@ -202,6 +202,8 @@ dependencies {
     // find bugs leaks in from spring, needed to remove warnings.
     compileOnly('com.google.code.findbugs:jsr305')
 
+    compileOnly('org.jetbrains:annotations')
+
     //Jgroups is a core component of our membership system.
     implementation('org.jgroups:jgroups')
 

geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/SocketMessageWriter.java

@@ -22,6 +22,8 @@
 import java.util.List;
 import java.util.Map;
 
+import org.jetbrains.annotations.Nullable;
+
 import org.apache.geode.DataSerializer;
 import org.apache.geode.Instantiator;
 import org.apache.geode.internal.InternalDataSerializer;
@@ -34,7 +36,8 @@ public class SocketMessageWriter {
       Integer.getInteger(GeodeGlossary.GEMFIRE_PREFIX + "serverToClientPingPeriod", 60000);
 
   public void writeHandshakeMessage(DataOutputStream dos, byte type, String p_msg,
-      KnownVersion clientVersion, byte endpointType, int queueSize) throws IOException {
+      @Nullable KnownVersion clientVersion, byte endpointType, int queueSize)
+      throws IOException {
     String msg = p_msg;
 
     // write the message type
@@ -48,40 +51,41 @@ public void writeHandshakeMessage(DataOutputStream dos, byte type, String p_msg,
     }
     dos.writeUTF(msg);
 
-    // get all the instantiators.
-    Instantiator[] instantiators = InternalInstantiator.getInstantiators();
-    Map<Integer, List<String>> instantiatorMap = new HashMap<>();
-    if (instantiators != null && instantiators.length > 0) {
-      for (Instantiator instantiator : instantiators) {
-        List<String> instantiatorAttributes = new ArrayList<>();
-        instantiatorAttributes.add(instantiator.getClass().toString().substring(6));
-        instantiatorAttributes.add(instantiator.getInstantiatedClass().toString().substring(6));
-        instantiatorMap.put(instantiator.getId(), instantiatorAttributes);
+    if (clientVersion != null) {
+      // get all the instantiators.
+      Instantiator[] instantiators = InternalInstantiator.getInstantiators();
+      Map<Integer, List<String>> instantiatorMap = new HashMap<>();
+      if (instantiators != null && instantiators.length > 0) {
+        for (Instantiator instantiator : instantiators) {
+          List<String> instantiatorAttributes = new ArrayList<>();
+          instantiatorAttributes.add(instantiator.getClass().toString().substring(6));
+          instantiatorAttributes.add(instantiator.getInstantiatedClass().toString().substring(6));
+          instantiatorMap.put(instantiator.getId(), instantiatorAttributes);
+        }
       }
-    }
-    DataSerializer.writeHashMap(instantiatorMap, dos);
+      DataSerializer.writeHashMap(instantiatorMap, dos);
 
-    // get all the dataserializers.
-    DataSerializer[] dataSerializers = InternalDataSerializer.getSerializers();
-    HashMap<Integer, ArrayList<String>> dsToSupportedClasses = new HashMap<>();
-    HashMap<Integer, String> dataSerializersMap = new HashMap<>();
-    if (dataSerializers != null && dataSerializers.length > 0) {
-      for (DataSerializer dataSerializer : dataSerializers) {
-        dataSerializersMap.put(dataSerializer.getId(),
-            dataSerializer.getClass().toString().substring(6));
-        ArrayList<String> supportedClassNames = new ArrayList<>();
-        for (Class<?> clazz : dataSerializer.getSupportedClasses()) {
-          supportedClassNames.add(clazz.getName());
+      // get all the dataserializers.
+      DataSerializer[] dataSerializers = InternalDataSerializer.getSerializers();
+      HashMap<Integer, ArrayList<String>> dsToSupportedClasses = new HashMap<>();
+      HashMap<Integer, String> dataSerializersMap = new HashMap<>();
+      if (dataSerializers != null && dataSerializers.length > 0) {
+        for (DataSerializer dataSerializer : dataSerializers) {
+          dataSerializersMap.put(dataSerializer.getId(),
+              dataSerializer.getClass().toString().substring(6));
+          ArrayList<String> supportedClassNames = new ArrayList<>();
+          for (Class<?> clazz : dataSerializer.getSupportedClasses()) {
+            supportedClassNames.add(clazz.getName());
+          }
+          dsToSupportedClasses.put(dataSerializer.getId(), supportedClassNames);
         }
-        dsToSupportedClasses.put(dataSerializer.getId(), supportedClassNames);
+      }
+      DataSerializer.writeHashMap(dataSerializersMap, dos);
+      DataSerializer.writeHashMap(dsToSupportedClasses, dos);
+      if (clientVersion.isNotOlderThan(KnownVersion.GEODE_1_5_0)) {
+        dos.writeInt(CLIENT_PING_TASK_PERIOD);
       }
     }
-    DataSerializer.writeHashMap(dataSerializersMap, dos);
-    DataSerializer.writeHashMap(dsToSupportedClasses, dos);
-    if (clientVersion.isNotOlderThan(KnownVersion.GEODE_1_5_0)) {
-      dos.writeInt(CLIENT_PING_TASK_PERIOD);
-    }
-
     dos.flush();
   }
 

geode-core/src/test/java/org/apache/geode/internal/cache/tier/sockets/SocketMessageWriterTest.java

@@ -0,0 +1,33 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
+ * agreements. See the NOTICE file distributed with this work for additional information regarding
+ * copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License. You may obtain a
+ * copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package org.apache.geode.internal.cache.tier.sockets;
+
+import java.io.ByteArrayOutputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+
+import org.junit.Test;
+
+public class SocketMessageWriterTest {
+
+  @Test
+  public void writeHandshakeMessageWithClientVersionNull() throws IOException {
+    final SocketMessageWriter writer = new SocketMessageWriter();
+    // can't mock DataOutputStream
+    final DataOutputStream outputStream = new DataOutputStream(new ByteArrayOutputStream());
+    writer.writeHandshakeMessage(outputStream, (byte) 1, "", null, (byte) 0, 0);
+  }
+}