8296804: Document HttpClient configuration properties in java.net.http module-info

Reviewed-by: dfuchs, jpai

Author: Michael-Mc-Mahon

src/java.net.http/share/classes/module-info.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,7 +25,137 @@
 
 /**
  * Defines the HTTP Client and WebSocket APIs.
- *
+ * <p>
+ * <b id="httpclientprops">System properties used by the java.net.http API</b>
+ * <p>
+ * The following is a list of system networking properties used by the java.net.http
+ * client implementation in the JDK. Any properties below that take a numeric value
+ * assume the default value if given a string that does not parse as a number.
+ * Unless otherwise specified below, all values can be set in the {@code conf/net.properties}
+ * file. In all cases, values can be specified as system properties on the command line,
+ * in which case, any value in {@code conf/net.properties} is overridden. No guarantee is
+ * provided that property values can be set programatically with {@code System.setProperty()}.
+ * Other implementations of this API may choose not to support these properties.
+ * <ul>
+ * <li><p><b>{@systemProperty jdk.httpclient.allowRestrictedHeaders}</b> (default: see below)<br>
+ * A comma-separated list of normally restricted HTTP header names that users may set in HTTP
+ * requests or by user code in HttpRequest instances. By default, the following request
+ * headers are not allowed to be set by user code: connection, content-length, expect, host,
+ * and upgrade. You can override this behavior with this property. The names are case-insensitive
+ * and whitespace is ignored. Note that this property is intended for testing and not for
+ * real-world deployments. Protocol errors or other undefined behavior are likely to occur
+ * when using this property. There may be other headers that are restricted from being set
+ * depending on the context. This includes the "Authorization" header when the relevant
+ * HttpClient has an authenticator set. These restrictions cannot be overridden by this
+ * property.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.bufsize}</b> (default: 16384 bytes or 16 kB)<br>
+ * The size to use for internal allocated buffers in bytes.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.connectionPoolSize}</b> (default: 0)<br>
+ * The maximum number of connections to keep in the HTTP/1.1 keep alive cache. A value of 0
+ * means that the cache is unbounded.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.connectionWindowSize}</b> (default: 2^26)<br>
+ * The HTTP/2 client connection window size in bytes. The maximum size is 2^31-1. This value
+ * cannot be smaller than the stream window size, which can be configured through the
+ * {@code jdk.httpclient.windowsize} system property.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.disableRetryConnect}</b> (default: false)<br>
+ * Whether automatic retry of connection failures is disabled. If false, then retries are
+ * attempted (subject to the retry limit).
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.enableAllMethodRetry}</b> (default: false)<br>
+ * Whether it is permitted to automatically retry non-idempotent HTTP requests.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.enablepush}</b> (default: 1)<br>
+ * Whether HTTP/2 push promise is enabled. A value of 1 enables push promise; a value of 0
+ * disables it.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.hpack.maxheadertablesize}</b> (default: 16384 or
+ * 16 kB)<br> The HTTP/2 client maximum HPACK header table size in bytes.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.HttpClient.log}</b> (default: none)<br>
+ * Enables high-level logging of various events through the {@linkplain java.lang.System.Logger
+ * Platform Logging API}. The value contains a comma-separated list of any of the
+ * following items:
+ * <ul>
+ *   <li>errors</li>
+ *   <li>requests</li>
+ *   <li>headers</li>
+ *   <li>content</li>
+ *   <li>frames</li>
+ *   <li>ssl</li>
+ *   <li>trace</li>
+ *   <li>channel</li>
+ * </ul><br>
+ * You can append the frames item with a colon-separated list of any of the following items:
+ * <ul>
+ *   <li>control</li>
+ *   <li>data</li>
+ *   <li>window</li>
+ *   <li>all</li>
+ * </ul><br>
+ * Specifying an item adds it to the HTTP client's log. For example, if you specify the
+ * following value, then the Platform Logging API logs all possible HTTP Client events:<br>
+ * "errors,requests,headers,frames:control:data:window,ssl,trace,channel"<br>
+ * Note that you can replace control:data:window with all. The name of the logger is
+ * "jdk.httpclient.HttpClient", and all logging is at level INFO.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.keepalive.timeout}</b> (default: 30)<br>
+ * The number of seconds to keep idle HTTP connections alive in the keep alive cache. This
+ * property applies to both HTTP/1.1 and HTTP/2. The value for HTTP/2 can be overridden
+ * with the {@code jdk.httpclient.keepalive.timeout.h2 property}.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.keepalive.timeout.h2}</b> (default: see
+ * below)<br>The number of seconds to keep idle HTTP/2 connections alive. If not set, then the
+ * {@code jdk.httpclient.keepalive.timeout} setting is used.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.maxframesize}</b> (default: 16384 or 16kB)<br>
+ * The HTTP/2 client maximum frame size in bytes. The server is not permitted to send a frame
+ * larger than this.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.maxstreams}</b> (default: 100)<br>
+ * The maximum number of HTTP/2 push streams that the client will permit servers to open
+ * simultaneously.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.receiveBufferSize}</b> (default: operating system
+ * default)<br>The HTTP client <a href="../java.base/java/net/StandardSocketOptions.html#SO_RCVBUF">
+ * socket receive buffer size</a> in bytes.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.redirects.retrylimit}</b> (default: 5)<br>
+ * The maximum number of attempts to send a HTTP request when redirected or any failure occurs
+ * for any reason.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.websocket.writeBufferSize}</b> (default: 16384
+ * or 16kB)<br>The buffer size used by the web socket implementation for socket writes.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.windowsize}</b> (default: 16777216 or 16 MB)<br>
+ * The HTTP/2 client stream window size in bytes.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.auth.retrylimit}</b> (default: 3)<br>
+ * The number of attempts the Basic authentication filter will attempt to retry a failed
+ * authentication.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.httpclient.sendBufferSize}</b> (default: operating system
+ * default)<br>The HTTP client socket
+ * <a href="../java.base/java/net/StandardSocketOptions.html#SO_SNDBUF">send buffer size</a>.
+ * Values less than or equal to zero are ignored.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.internal.httpclient.disableHostnameVerification}</b> (default:
+ * false)<br>If true (or set to an empty string), hostname verification in SSL certificates
+ * is disabled. This is a system property only and not available in {@code conf/net.properties}.
+ * It is provided for testing purposes only.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.http.auth.proxying.disabledSchemes}</b> (default: see
+ * conf/net.properties)<br>A comma separated list of HTTP authentication scheme names,
+ * that are disallowed for use by the HTTP client implementation, for HTTP proxying.
+ * </li>
+ * <li><p><b>{@systemProperty jdk.http.auth.tunneling.disabledSchemes}</b> (default: see
+ * conf/net.properties)<br>A comma separated list of HTTP authentication scheme names, that
+ * are disallowed for use by the HTTP client implementation, for HTTP CONNECT tunneling.
+ * </li>
+ * </ul>
  * @moduleGraph
  * @since 11
  */