Update links to the latest HTTP/2 specifications (#9493)

Motivation:

Some of the links in javadoc point to the obsolete drafts of HTTP/2
specifications. We should point them to the latest RFC 7540 or 7541.

Modifications:

Update links from `draft-ietf-httpbis-*` to the `rfc7540` and `rfc7541`.

Result:

Correct links in javadoc.

codec-http/src/main/java/io/netty/handler/codec/http/HttpResponseStatus.java

@@ -225,7 +225,7 @@ public class HttpResponseStatus implements Comparable<HttpResponseStatus> {
     /**
      * 421 Misdirected Request
      *
-     * <a href="https://tools.ietf.org/html/draft-ietf-httpbis-http2-15#section-9.1.2">421 Status Code</a>
+     * @see <a href="https://tools.ietf.org/html/rfc7540#section-9.1.2">421 (Misdirected Request) Status Code</a>
      */
     public static final HttpResponseStatus MISDIRECTED_REQUEST = newStatus(421, "Misdirected Request");
 

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2FrameListener.java

@@ -160,7 +160,7 @@ public interface Http2FrameListener {
      * Handles an inbound {@code PUSH_PROMISE} frame. Only called if {@code END_HEADERS} encountered.
      * <p>
      * Promised requests MUST be authoritative, cacheable, and safe.
-     * See <a href="https://tools.ietf.org/html/draft-ietf-httpbis-http2-17#section-8.2">[RFC http2], Section 8.2</a>.
+     * See <a href="https://tools.ietf.org/html/rfc7540#section-8.2">[RFC 7540], Section 8.2</a>.
      * <p>
      * Only one of the following methods will be called for each {@code HEADERS} frame sequence.
      * One will be called when the {@code END_HEADERS} flag has been received.

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2HeadersEncoder.java

@@ -57,17 +57,18 @@ public interface Http2HeadersEncoder {
 
     /**
      * Determine if a header name/value pair is treated as
-     * <a href="http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-12#section-7.1.3">sensitive</a>.
+     * <a href="https://tools.ietf.org/html/rfc7541#section-7.1.3">sensitive</a>.
      * If the object can be dynamically modified and shared across multiple connections it may need to be thread safe.
      */
     interface SensitivityDetector {
         /**
          * Determine if a header {@code name}/{@code value} pair should be treated as
-         * <a href="http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-12#section-7.1.3">sensitive</a>.
+         * <a href="https://tools.ietf.org/html/rfc7541#section-7.1.3">sensitive</a>.
+         *
          * @param name The name for the header.
          * @param value The value of the header.
          * @return {@code true} if a header {@code name}/{@code value} pair should be treated as
-         * <a href="http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-12#section-7.1.3">sensitive</a>.
+         * <a href="https://tools.ietf.org/html/rfc7541#section-7.1.3">sensitive</a>.
          * {@code false} otherwise.
          */
         boolean isSensitive(CharSequence name, CharSequence value);

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2PromisedRequestVerifier.java

@@ -19,7 +19,7 @@ import io.netty.util.internal.UnstableApi;
 
 /**
  * Provides an extensibility point for users to define the validity of push requests.
- * @see <a href="https://tools.ietf.org/html/draft-ietf-httpbis-http2-17#section-8.2">[RFC http2], Section 8.2</a>.
+ * @see <a href="https://tools.ietf.org/html/rfc7540#section-8.2">[RFC 7540], Section 8.2</a>.
  */
 @UnstableApi
 public interface Http2PromisedRequestVerifier {
@@ -29,7 +29,7 @@ public interface Http2PromisedRequestVerifier {
      * @param headers The headers to be verified.
      * @return {@code true} if the {@code ctx} is authoritative for the {@code headers}, {@code false} otherwise.
      * @see
-     * <a href="https://tools.ietf.org/html/draft-ietf-httpbis-http2-17#section-10.1">[RFC http2], Section 10.1</a>.
+     * <a href="https://tools.ietf.org/html/rfc7540#section-10.1">[RFC 7540], Section 10.1</a>.
      */
     boolean isAuthoritative(ChannelHandlerContext ctx, Http2Headers headers);
 

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2SecurityUtil.java

@@ -33,7 +33,7 @@ public final class Http2SecurityUtil {
      * Ciphers</a> and <a
      * href="https://wiki.mozilla.org/Security/Server_Side_TLS#Modern_compatibility">Mozilla Modern Cipher
      * Suites</a> in accordance with the <a
-     * href="https://tools.ietf.org/html/draft-ietf-httpbis-http2-16#section-9.2.2">HTTP/2 Specification</a>.
+     * href="https://tools.ietf.org/html/rfc7540#section-9.2.2">HTTP/2 Specification</a>.
      *
      * According to the <a href="http://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html">
      * JSSE documentation</a> "the names mentioned in the TLS RFCs prefixed with TLS_ are functionally equivalent

codec-http2/src/main/java/io/netty/handler/codec/http2/HttpConversionUtil.java

@@ -92,24 +92,24 @@ public final class HttpConversionUtil {
 
     /**
      * This will be the method used for {@link HttpRequest} objects generated out of the HTTP message flow defined in <a
-     * href="http://tools.ietf.org/html/draft-ietf-httpbis-http2-16#section-8.1.">HTTP/2 Spec Message Flow</a>
+     * href="https://tools.ietf.org/html/rfc7540#section-8.1">[RFC 7540], Section 8.1</a>
      */
     public static final HttpMethod OUT_OF_MESSAGE_SEQUENCE_METHOD = HttpMethod.OPTIONS;
 
     /**
      * This will be the path used for {@link HttpRequest} objects generated out of the HTTP message flow defined in <a
-     * href="http://tools.ietf.org/html/draft-ietf-httpbis-http2-16#section-8.1.">HTTP/2 Spec Message Flow</a>
+     * href="https://tools.ietf.org/html/rfc7540#section-8.1">[RFC 7540], Section 8.1</a>
      */
     public static final String OUT_OF_MESSAGE_SEQUENCE_PATH = "";
 
     /**
      * This will be the status code used for {@link HttpResponse} objects generated out of the HTTP message flow defined
-     * in <a href="http://tools.ietf.org/html/draft-ietf-httpbis-http2-16#section-8.1.">HTTP/2 Spec Message Flow</a>
+     * in <a href="https://tools.ietf.org/html/rfc7540#section-8.1">[RFC 7540], Section 8.1</a>
      */
     public static final HttpResponseStatus OUT_OF_MESSAGE_SEQUENCE_RETURN_CODE = HttpResponseStatus.OK;
 
     /**
-     * <a href="https://tools.ietf.org/html/rfc7540#section-8.1.2.3">rfc7540, 8.1.2.3</a> states the path must not
+     * <a href="https://tools.ietf.org/html/rfc7540#section-8.1.2.3">[RFC 7540], 8.1.2.3</a> states the path must not
      * be empty, and instead should be {@code /}.
      */
     private static final AsciiString EMPTY_REQUEST_PATH = AsciiString.cached("/");

codec-http2/src/main/java/io/netty/handler/codec/http2/InboundHttp2ToHttpAdapter.java

@@ -34,7 +34,7 @@ import static java.util.Objects.requireNonNull;
 
 /**
  * This adapter provides just header/data events from the HTTP message flow defined
- * here <a href="http://tools.ietf.org/html/draft-ietf-httpbis-http2-16#section-8.1.">HTTP/2 Spec Message Flow</a>.
+ * in <a href="https://tools.ietf.org/html/rfc7540#section-8.1">[RFC 7540], Section 8.1</a>.
  * <p>
  * See {@link HttpToHttp2ConnectionHandler} to get translation from HTTP/1.x objects to HTTP/2 frames for writes.
  */