Enabled NullAway for the root package

client/src/main/java/org/asynchttpclient/AsyncCompletionHandler.java

@@ -18,6 +18,7 @@
 
 import io.netty.handler.codec.http.HttpHeaders;
 import org.asynchttpclient.handler.ProgressAsyncHandler;
+import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -66,7 +67,7 @@ public State onTrailingHeadersReceived(HttpHeaders headers) throws Exception {
     }
 
     @Override
-    public final T onCompleted() throws Exception {
+    public final @Nullable T onCompleted() throws Exception {
         return onCompleted(builder.build());
     }
 
@@ -83,7 +84,7 @@ public void onThrowable(Throwable t) {
      * {@link Future}
      * @throws Exception if something wrong happens
      */
-    public abstract T onCompleted(Response response) throws Exception;
+    public abstract @Nullable T onCompleted(@Nullable Response response) throws Exception;
 
     /**
      * Invoked when the HTTP headers have been fully written on the I/O socket.

client/src/main/java/org/asynchttpclient/AsyncCompletionHandlerBase.java

@@ -17,12 +17,14 @@
 package org.asynchttpclient;
 
 
+import org.jetbrains.annotations.Nullable;
+
 /**
  * Simple {@link AsyncHandler} of type {@link Response}
  */
 public class AsyncCompletionHandlerBase extends AsyncCompletionHandler<Response> {
     @Override
-    public Response onCompleted(Response response) throws Exception {
+    public @Nullable Response onCompleted(@Nullable Response response) throws Exception {
         return response;
     }
 }

client/src/main/java/org/asynchttpclient/AsyncHandler.java

@@ -18,6 +18,7 @@
 import io.netty.channel.Channel;
 import io.netty.handler.codec.http.HttpHeaders;
 import org.asynchttpclient.netty.request.NettyRequest;
+import org.jetbrains.annotations.Nullable;
 
 import javax.net.ssl.SSLSession;
 import java.net.InetSocketAddress;
@@ -115,7 +116,7 @@ default State onTrailingHeadersReceived(HttpHeaders headers) throws Exception {
      * @return T Value that will be returned by the associated {@link Future}
      * @throws Exception if something wrong happens
      */
-    T onCompleted() throws Exception;
+    @Nullable T onCompleted() throws Exception;
 
     /**
      * Notify the callback before hostname resolution

client/src/main/java/org/asynchttpclient/AsyncHttpClientConfig.java

@@ -34,6 +34,7 @@
 import org.asynchttpclient.netty.channel.ConnectionSemaphoreFactory;
 import org.asynchttpclient.proxy.ProxyServer;
 import org.asynchttpclient.proxy.ProxyServerSelector;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.IOException;
 import java.time.Duration;
@@ -159,7 +160,7 @@ public interface AsyncHttpClientConfig {
      * @return the {@link ThreadFactory} an {@link AsyncHttpClient} use for handling asynchronous response. If no {@link ThreadFactory} has been explicitly
      * provided, this method will return {@code null}
      */
-    ThreadFactory getThreadFactory();
+    @Nullable ThreadFactory getThreadFactory();
 
     /**
      * An instance of {@link ProxyServer} used by an {@link AsyncHttpClient}
@@ -173,14 +174,14 @@ public interface AsyncHttpClientConfig {
      *
      * @return an instance of {@link SslContext} used for SSL connection.
      */
-    SslContext getSslContext();
+    @Nullable SslContext getSslContext();
 
     /**
      * Return the current {@link Realm}
      *
      * @return the current {@link Realm}
      */
-    Realm getRealm();
+    @Nullable Realm getRealm();
 
     /**
      * Return the list of {@link RequestFilter}
@@ -259,12 +260,12 @@ public interface AsyncHttpClientConfig {
     /**
      * @return the array of enabled protocols
      */
-    String[] getEnabledProtocols();
+    @Nullable String[] getEnabledProtocols();
 
     /**
      * @return the array of enabled cipher suites
      */
-    String[] getEnabledCipherSuites();
+    @Nullable String[] getEnabledCipherSuites();
 
     /**
      * @return if insecure cipher suites must be filtered out (only used when not explicitly passing enabled cipher suites)
@@ -293,7 +294,7 @@ public interface AsyncHttpClientConfig {
 
     int getHandshakeTimeout();
 
-    SslEngineFactory getSslEngineFactory();
+    @Nullable SslEngineFactory getSslEngineFactory();
 
     int getChunkedFileChunkSize();
 
@@ -309,23 +310,23 @@ public interface AsyncHttpClientConfig {
 
     Map<ChannelOption<Object>, Object> getChannelOptions();
 
-    EventLoopGroup getEventLoopGroup();
+    @Nullable EventLoopGroup getEventLoopGroup();
 
     boolean isUseNativeTransport();
 
     boolean isUseOnlyEpollNativeTransport();
 
-    Consumer<Channel> getHttpAdditionalChannelInitializer();
+    @Nullable Consumer<Channel> getHttpAdditionalChannelInitializer();
 
-    Consumer<Channel> getWsAdditionalChannelInitializer();
+    @Nullable Consumer<Channel> getWsAdditionalChannelInitializer();
 
     ResponseBodyPartFactory getResponseBodyPartFactory();
 
-    ChannelPool getChannelPool();
+    @Nullable ChannelPool getChannelPool();
 
-    ConnectionSemaphoreFactory getConnectionSemaphoreFactory();
+    @Nullable ConnectionSemaphoreFactory getConnectionSemaphoreFactory();
 
-    Timer getNettyTimer();
+    @Nullable Timer getNettyTimer();
 
     /**
      * @return the duration between tick of {@link HashedWheelTimer}
@@ -357,7 +358,7 @@ public interface AsyncHttpClientConfig {
 
     int getSoRcvBuf();
 
-    ByteBufAllocator getAllocator();
+    @Nullable ByteBufAllocator getAllocator();
 
     int getIoThreadsCount();
 

client/src/main/java/org/asynchttpclient/DefaultAsyncHttpClient.java

@@ -30,6 +30,7 @@
 import org.asynchttpclient.handler.resumable.ResumableAsyncHandler;
 import org.asynchttpclient.netty.channel.ChannelManager;
 import org.asynchttpclient.netty.request.NettyRequestSender;
+import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -68,7 +69,7 @@ public class DefaultAsyncHttpClient implements AsyncHttpClient {
      * Default signature calculator to use for all requests constructed by this
      * client instance.
      */
-    private SignatureCalculator signatureCalculator;
+    private @Nullable SignatureCalculator signatureCalculator;
 
     /**
      * Create a new HTTP Asynchronous Client using the default
@@ -95,8 +96,14 @@ public DefaultAsyncHttpClient(AsyncHttpClientConfig config) {
 
         this.config = config;
         noRequestFilters = config.getRequestFilters().isEmpty();
-        allowStopNettyTimer = config.getNettyTimer() == null;
-        nettyTimer = allowStopNettyTimer ? newNettyTimer(config) : config.getNettyTimer();
+        final Timer configTimer = config.getNettyTimer();
+        if (configTimer == null) {
+            allowStopNettyTimer = true;
+            nettyTimer = newNettyTimer(config);
+        } else {
+            allowStopNettyTimer = false;
+            nettyTimer = configTimer;
+        }
 
         channelManager = new ChannelManager(config, nettyTimer);
         requestSender = new NettyRequestSender(config, channelManager, nettyTimer, new AsyncHttpClientState(closed));