AlpnWrapper Class — netty Architecture

Source Code

handler/src/main/java/io/netty/handler/ssl/JdkAlpnApplicationProtocolNegotiator.java lines 127–148

    private static final class AlpnWrapper extends AllocatorAwareSslEngineWrapperFactory {
        @Override
        public SSLEngine wrapSslEngine(SSLEngine engine, ByteBufAllocator alloc,
                                       JdkApplicationProtocolNegotiator applicationNegotiator, boolean isServer) {
            if (Conscrypt.isEngineSupported(engine)) {
                return isServer ? ConscryptAlpnSslEngine.newServerEngine(engine, alloc, applicationNegotiator)
                        : ConscryptAlpnSslEngine.newClientEngine(engine, alloc, applicationNegotiator);
            }
            if (BouncyCastleUtil.isBcJsseInUse(engine) && BouncyCastleAlpnSslUtils.isAlpnSupported()) {
                return new BouncyCastleAlpnSslEngine(engine, applicationNegotiator, isServer);
            }
            // ALPN support was recently backported to Java8 as
            // https://bugs.java.com/bugdatabase/view_bug.do?bug_id=8230977.
            // Because of this lets not do a Java version runtime check but just depend on if the required methods are
            // present
            if (JdkAlpnSslUtils.supportsAlpn()) {
                return new JdkAlpnSslEngine(engine, applicationNegotiator, isServer);
            }
            throw new UnsupportedOperationException("ALPN not supported. Unable to wrap SSLEngine of type '"
                    + engine.getClass().getName() + "')");
        }
    }