default to retry when http2 closed exception occurred (#70)

httpclient-core/src/main/java/esa/httpclient/core/exception/ClosedConnectionException.java

@@ -19,9 +19,6 @@
 
 public class ClosedConnectionException extends IOException {
 
-    public static final ClosedConnectionException INSTANCE = new ClosedConnectionException(
-            "Connection is inactive");
-
     private static final long serialVersionUID = -7491330351921922628L;
 
     public ClosedConnectionException(String msg) {

httpclient-core/src/main/java/esa/httpclient/core/exception/ClosedStreamException.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2021 OPPO ESA Stack Project
+ *
+ * Licensed 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 esa.httpclient.core.exception;
+
+import java.io.IOException;
+
+public class ClosedStreamException extends IOException {
+
+    public static final ClosedStreamException CAUSED_BY_RST =
+            new ClosedStreamException("Received reset stream and current stream will be discarded");
+
+    public static final ClosedStreamException CAUSED_BY_REMOVED =
+            new ClosedStreamException("Stream has been removed");
+
+    private static final long serialVersionUID = -7491330351921922628L;
+
+    public ClosedStreamException(String msg) {
+        super(msg);
+    }
+}
+

httpclient-core/src/main/java/esa/httpclient/core/exec/RetryPredicateImpl.java

@@ -19,6 +19,7 @@
 import esa.httpclient.core.HttpRequest;
 import esa.httpclient.core.HttpResponse;
 import esa.httpclient.core.exception.ClosedConnectionException;
+import esa.httpclient.core.exception.ClosedStreamException;
 import esa.httpclient.core.util.Futures;
 
 import java.net.ConnectException;
@@ -40,7 +41,9 @@ public boolean canRetry(HttpRequest request,
         }
 
         final Throwable unwrapped = Futures.unwrapped(cause);
-        if (unwrapped instanceof ConnectException || unwrapped instanceof ClosedConnectionException) {
+        if (unwrapped instanceof ConnectException
+                || unwrapped instanceof ClosedConnectionException
+                || unwrapped instanceof ClosedStreamException) {
             return true;
         }
 

httpclient-core/src/main/java/esa/httpclient/core/netty/Http2FrameHandler.java

@@ -19,7 +19,7 @@
 import esa.commons.netty.core.BufferImpl;
 import esa.commons.netty.http.Http2HeadersAdaptor;
 import esa.httpclient.core.Context;
-import esa.httpclient.core.exception.ClosedConnectionException;
+import esa.httpclient.core.exception.ClosedStreamException;
 import esa.httpclient.core.exception.ContentOverSizedException;
 import esa.httpclient.core.util.HttpHeadersUtils;
 import esa.httpclient.core.util.LoggerUtils;
@@ -30,7 +30,6 @@
 import io.netty.handler.codec.http.HttpStatusClass;
 import io.netty.handler.codec.http2.Http2CodecUtil;
 import io.netty.handler.codec.http2.Http2Connection;
-import io.netty.handler.codec.http2.Http2Error;
 import io.netty.handler.codec.http2.Http2EventAdapter;
 import io.netty.handler.codec.http2.Http2Exception;
 import io.netty.handler.codec.http2.Http2Headers;
@@ -155,8 +154,11 @@ public void onRstStreamRead(ChannelHandlerContext ctx,
                                 long errorCode) {
         final Http2Stream stream = connection.stream(streamId);
         if (stream != null) {
-            onError(Http2Exception.streamError(streamId, Http2Error.valueOf(errorCode),
-                    "Received reset stream"), stream, streamId, true);
+            final Throwable ex = ClosedStreamException.CAUSED_BY_RST;
+            if (LoggerUtils.logger().isDebugEnabled()) {
+                LoggerUtils.logger().debug(ex.getMessage());
+            }
+            onError(ex, stream, streamId, false);
         }
     }
 
@@ -165,12 +167,12 @@ public void onGoAwayRead(ChannelHandlerContext ctx, int lastStreamId,
                              long errorCode, ByteBuf debugData) throws Http2Exception {
         final String errMsg = debugData.toString(StandardCharsets.UTF_8);
 
-        final ClosedConnectionException ex;
+        final ClosedStreamException ex;
         if (NO_ERROR.code() == errorCode) {
-            ex = new ClosedConnectionException("Received goAway stream in connection: " + ctx.channel()
+            ex = new ClosedStreamException("Received goAway stream in connection: " + ctx.channel()
                     + ", maybe server has closed the connection");
         } else {
-            ex = new ClosedConnectionException("Received goAway stream in connection: " +
+            ex = new ClosedStreamException("Received goAway stream in connection: " +
                     ctx.channel() + ", msg: " + errMsg);
         }
 
@@ -221,8 +223,8 @@ public void onStreamRemoved(Http2Stream stream) {
         try {
             super.onStreamRemoved(stream);
         } finally {
-            onError(Http2Exception.streamError(stream.id(), Http2Error.STREAM_CLOSED, "Stream removed"),
-                    stream, -1, false);
+            final Throwable ex = ClosedStreamException.CAUSED_BY_REMOVED;
+            onError(ex, stream, -1, false);
         }
     }
 

httpclient-core/src/main/java/esa/httpclient/core/netty/NettyHandle.java

@@ -139,7 +139,7 @@ private void onError0(Throwable cause) {
 
             listener.onError(request, ctx, cause);
         } catch (Throwable ex) {
-            LoggerUtils.logger().warn("Unexpected exception occurred on handle#onError0", cause);
+            LoggerUtils.logger().error("Unexpected exception occurred on handle#onError0", cause);
         }
     }
 

httpclient-core/src/test/java/esa/httpclient/core/exec/RetryPredicateImplTest.java

@@ -19,6 +19,7 @@
 import esa.httpclient.core.HttpRequest;
 import esa.httpclient.core.HttpResponse;
 import esa.httpclient.core.exception.ClosedConnectionException;
+import esa.httpclient.core.exception.ClosedStreamException;
 import org.junit.jupiter.api.Test;
 
 import java.net.ConnectException;
@@ -36,7 +37,9 @@ void testCanRetry() {
         then(predicate.canRetry(mock(HttpRequest.class), mock(HttpResponse.class), mock(Context.class),
                 new ConnectException())).isTrue();
         then(predicate.canRetry(mock(HttpRequest.class), mock(HttpResponse.class), mock(Context.class),
-                ClosedConnectionException.INSTANCE)).isTrue();
+                new ClosedConnectionException(""))).isTrue();
+        then(predicate.canRetry(mock(HttpRequest.class), mock(HttpResponse.class), mock(Context.class),
+                new ClosedStreamException(""))).isTrue();
         then(predicate.canRetry(mock(HttpRequest.class), mock(HttpResponse.class), mock(Context.class),
                 new RuntimeException())).isFalse();
     }