Improve javadoc

Author: arturobernalg

httpclient5/src/main/java/org/apache/hc/client5/http/impl/AlpnHeaderSupport.java

@@ -42,7 +42,7 @@
 /**
  * Codec for the HTTP {@code ALPN} header field (RFC 7639).
  *
- * @since 5.4
+ * @since 5.6
  */
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 @Internal

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClientBuilder.java

@@ -914,6 +914,20 @@ public final HttpAsyncClientBuilder disableRequestPriority() {
         return this;
     }
 
+    /**
+     * Configures the {@code ALPN} header  to be sent on {@code CONNECT}
+     * requests when establishing an HTTP tunnel through a proxy.
+     *
+     * <p>The supplied protocol IDs are advertised in the given order (preference order).
+     * If {@code ids} is {@code null} or empty, no {@code ALPN} header will be added.</p>
+     *
+     * <p>This is a convenience method equivalent to installing a {@link ConnectAlpnProvider}
+     * that always returns the same list.</p>
+     *
+     * @param ids ALPN protocol IDs to advertise (for example {@code "h2"} and {@code "http/1.1"})
+     * @return this builder
+     * @since 5.6
+     */
     public HttpAsyncClientBuilder setConnectAlpn(final String... ids) {
         final List<String> list = ids != null && ids.length > 0 ? Arrays.asList(ids) : Collections.emptyList();
         this.connectAlpnProvider = (t, r) -> list;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/HttpClientBuilder.java

@@ -812,6 +812,20 @@ public final HttpClientBuilder setProxySelector(final ProxySelector proxySelecto
         return this;
     }
 
+    /**
+     * Configures the {@code ALPN} header  to be sent on {@code CONNECT}
+     * requests when establishing an HTTP tunnel through a proxy.
+     *
+     * <p>The supplied protocol IDs are advertised in the given order (preference order).
+     * If {@code ids} is {@code null} or empty, no {@code ALPN} header will be added.</p>
+     *
+     * <p>This is a convenience method equivalent to installing a {@link ConnectAlpnProvider}
+     * that always returns the same list.</p>
+     *
+     * @param ids ALPN protocol IDs to advertise (for example {@code "h2"} and {@code "http/1.1"})
+     * @return this builder
+     * @since 5.6
+     */
     public HttpClientBuilder setConnectAlpn(final String... ids) {
         final List<String> list = ids != null && ids.length > 0 ? Arrays.asList(ids) : Collections.emptyList();
         this.connectAlpnProvider = (t, r) -> list;

httpclient5/src/test/java/org/apache/hc/client5/http/examples/ClassicConnectAlpnEndToEndDemo.java

@@ -31,6 +31,7 @@
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
+import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
@@ -91,7 +92,7 @@ public static void main(final String[] args) throws Exception {
         final int originPort = origin.getLocalPort();
 
         // ---- Tiny blocking proxy printing ALPN and tunneling bytes
-        final ServerSocket proxyServer = new ServerSocket(0, 50, java.net.InetAddress.getByName("127.0.0.1"));
+        final ServerSocket proxyServer = new ServerSocket(0, 50, InetAddress.getByName("127.0.0.1"));
         final int proxyPort = proxyServer.getLocalPort();
         final ExecutorService proxyPool = Executors.newCachedThreadPool();
         proxyPool.submit(() -> {