[#2812] Ensure we call checkForSharableAnnotation in all constructors of ByteToMessageCodec

Motivation:

ByteToMessageCodec miss to check for @Sharable annotation in one of its constructors.

Modifications:

Ensure we call checkForSharableAnnotation in all constructors.

Result:

After your change, what will change.

codec/src/main/java/io/netty/handler/codec/ByteToMessageCodec.java

@@ -70,6 +70,7 @@ public abstract class ByteToMessageCodec<I> extends ChannelHandlerAdapter {
      *                              {@link ByteBuf}, which is backed by an byte array.
      */
     protected ByteToMessageCodec(boolean preferDirect) {
+        checkForSharableAnnotation();
         outboundMsgMatcher = TypeParameterMatcher.find(this, ByteToMessageCodec.class, "I");
         encoder = new Encoder(preferDirect);
     }

codec/src/test/java/io/netty/handler/codec/ByteToMessageCodecTest.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2014 The Netty Project
+ *
+ * The Netty Project 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 io.netty.handler.codec;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandler;
+import io.netty.channel.ChannelHandlerContext;
+import org.junit.Test;
+
+import java.util.List;
+
+public class ByteToMessageCodecTest {
+
+    @Test(expected = IllegalStateException.class)
+    public void testSharable() {
+        new InvalidByteToMessageCodec();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void testSharable2() {
+        new InvalidByteToMessageCodec2();
+    }
+
+    @ChannelHandler.Sharable
+    private static final class InvalidByteToMessageCodec extends ByteToMessageCodec<Integer> {
+        InvalidByteToMessageCodec() {
+            super(true);
+        }
+
+        @Override
+        protected void encode(ChannelHandlerContext ctx, Integer msg, ByteBuf out) throws Exception { }
+
+        @Override
+        protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception { }
+    }
+
+    @ChannelHandler.Sharable
+    private static final class InvalidByteToMessageCodec2 extends ByteToMessageCodec<Integer> {
+        InvalidByteToMessageCodec2() {
+            super(Integer.class, true);
+        }
+
+        @Override
+        protected void encode(ChannelHandlerContext ctx, Integer msg, ByteBuf out) throws Exception { }
+
+        @Override
+        protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception { }
+    }
+}