Enabled NullAway for "handler" package (#1879)

Author: Asapin

client/src/main/java/org/asynchttpclient/handler/BodyDeferringAsyncHandler.java

@@ -17,6 +17,7 @@
 import org.asynchttpclient.HttpResponseBodyPart;
 import org.asynchttpclient.HttpResponseStatus;
 import org.asynchttpclient.Response;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.FilterInputStream;
 import java.io.IOException;
@@ -88,8 +89,8 @@ public class BodyDeferringAsyncHandler implements AsyncHandler<Response> {
     private final OutputStream output;
     private final Semaphore semaphore = new Semaphore(1);
     private boolean responseSet;
-    private volatile Response response;
-    private volatile Throwable throwable;
+    private volatile @Nullable Response response;
+    private volatile @Nullable Throwable throwable;
 
     public BodyDeferringAsyncHandler(final OutputStream os) {
         output = os;
@@ -166,7 +167,7 @@ protected void closeOut() throws IOException {
     }
 
     @Override
-    public Response onCompleted() throws IOException {
+    public @Nullable Response onCompleted() throws IOException {
 
         if (!responseSet) {
             response = responseBuilder.build();
@@ -217,7 +218,7 @@ public Response onCompleted() throws IOException {
      * @throws InterruptedException if the latch is interrupted
      * @throws IOException          if the handler completed with an exception
      */
-    public Response getResponse() throws InterruptedException, IOException {
+    public @Nullable Response getResponse() throws InterruptedException, IOException {
         // block here as long as headers arrive
         headersArrived.await();
 
@@ -278,7 +279,7 @@ public void close() throws IOException {
          * @throws InterruptedException if the latch is interrupted
          * @throws IOException          if the handler completed with an exception
          */
-        public Response getAsapResponse() throws InterruptedException, IOException {
+        public @Nullable Response getAsapResponse() throws InterruptedException, IOException {
             return bdah.getResponse();
         }
 

client/src/main/java/org/asynchttpclient/handler/TransferCompletionHandler.java

@@ -17,6 +17,7 @@
 import org.asynchttpclient.AsyncHandler;
 import org.asynchttpclient.HttpResponseBodyPart;
 import org.asynchttpclient.Response;
+import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -59,7 +60,7 @@ public class TransferCompletionHandler extends AsyncCompletionHandlerBase {
 
     private final ConcurrentLinkedQueue<TransferListener> listeners = new ConcurrentLinkedQueue<>();
     private final boolean accumulateResponseBytes;
-    private HttpHeaders headers;
+    private @Nullable HttpHeaders headers;
 
     /**
      * Create a TransferCompletionHandler that will not accumulate bytes. The resulting {@link Response#getResponseBody()},
@@ -116,7 +117,7 @@ public State onBodyPartReceived(final HttpResponseBodyPart content) throws Excep
     }
 
     @Override
-    public Response onCompleted(Response response) throws Exception {
+    public @Nullable Response onCompleted(@Nullable Response response) throws Exception {
         fireOnEnd();
         return response;
     }

client/src/main/java/org/asynchttpclient/handler/resumable/ResumableAsyncHandler.java

@@ -21,11 +21,13 @@
 import org.asynchttpclient.Response;
 import org.asynchttpclient.Response.ResponseBuilder;
 import org.asynchttpclient.handler.TransferCompletionHandler;
+import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.ConcurrentLinkedQueue;
@@ -47,18 +49,18 @@
 public class ResumableAsyncHandler implements AsyncHandler<Response> {
     private static final Logger logger = LoggerFactory.getLogger(TransferCompletionHandler.class);
     private static final ResumableIndexThread resumeIndexThread = new ResumableIndexThread();
-    private static Map<String, Long> resumableIndex;
+    private static Map<String, Long> resumableIndex = Collections.emptyMap();
 
     private final AtomicLong byteTransferred;
     private final ResumableProcessor resumableProcessor;
-    private final AsyncHandler<Response> decoratedAsyncHandler;
+    private final @Nullable AsyncHandler<Response> decoratedAsyncHandler;
     private final boolean accumulateBody;
-    private String url;
+    private String url = "";
     private final ResponseBuilder responseBuilder = new ResponseBuilder();
     private ResumableListener resumableListener = new NULLResumableListener();
 
-    private ResumableAsyncHandler(long byteTransferred, ResumableProcessor resumableProcessor,
-                                  AsyncHandler<Response> decoratedAsyncHandler, boolean accumulateBody) {
+    private ResumableAsyncHandler(long byteTransferred, @Nullable ResumableProcessor resumableProcessor,
+                                  @Nullable AsyncHandler<Response> decoratedAsyncHandler, boolean accumulateBody) {
 
         this.byteTransferred = new AtomicLong(byteTransferred);
 
@@ -152,7 +154,7 @@ public State onBodyPartReceived(HttpResponseBodyPart bodyPart) throws Exception
     }
 
     @Override
-    public Response onCompleted() throws Exception {
+    public @Nullable Response onCompleted() throws Exception {
         resumableProcessor.remove(url);
         resumableListener.onAllBytesReceived();
 

pom.xml

@@ -233,7 +233,7 @@
                             -Xep:NullOptional:ERROR
                             -XepExcludedPaths:.*/src/test/java/.*
                             -XepOpt:NullAway:AnnotatedPackages=org.asynchttpclient
-                            -XepOpt:NullAway:UnannotatedSubPackages=org.asynchttpclient.handler,org.asynchttpclient.netty,org.asynchttpclient.ntlm,org.asynchttpclient.request,org.asynchttpclient.spnego,org.asynchttpclient.uri,org.asynchttpclient.util,org.asynchttpclient.webdav,org.asynchttpclient.ws
+                            -XepOpt:NullAway:UnannotatedSubPackages=org.asynchttpclient.netty,org.asynchttpclient.ntlm,org.asynchttpclient.request,org.asynchttpclient.spnego,org.asynchttpclient.uri,org.asynchttpclient.util,org.asynchttpclient.webdav,org.asynchttpclient.ws
                             -XepOpt:NullAway:AcknowledgeRestrictiveAnnotations=true
                             -Xep:NullAway:ERROR
                         </arg>