= update external source code info in docs and comments

Author: oldratlee

library/README.md

@@ -314,10 +314,11 @@ private static void cacheAddresses(String hostname,
     该项目的[使用文档](http://leopard.io/modules/javahost)。  
     本项目如何设置`Java DNS Cache`的解法来自该项目。刚开始在持续集成项目中碰到`host`绑定的问题时，也是使用该项目来解决的 :+1:
 - 类`InetAddress`的源代码：
-    - `JDK 6`的[`InetAddress`](http://hg.openjdk.java.net/jdk6/jdk6/jdk/file/tip/src/share/classes/java/net/InetAddress.java#l739)
-    - `JDK 7`的[`InetAddress`](http://hg.openjdk.java.net/jdk7u/jdk7u/jdk/file/tip/src/share/classes/java/net/InetAddress.java#l742)
-    - `JDK 8`的[`InetAddress`](http://hg.openjdk.java.net/jdk8u/jdk8u/jdk/file/tip/src/share/classes/java/net/InetAddress.java#l748)
-    - `JDK 9`的[`InetAddress`](http://hg.openjdk.java.net/jdk9/jdk9/jdk/file/65464a307408/src/java.base/share/classes/java/net/InetAddress.java#783)
+    - `JDK 6`的[`InetAddress`](https://hg.openjdk.java.net/jdk6/jdk6/jdk/file/8deef18bb749/src/share/classes/java/net/InetAddress.java#l739)
+    - `JDK 7`的[`InetAddress`](https://hg.openjdk.java.net/jdk7u/jdk7u/jdk/file/4dd5e486620d/src/share/classes/java/net/InetAddress.java#l742)
+    - `JDK 8`的[`InetAddress`](https://hg.openjdk.java.net/jdk8u/jdk8u/jdk/file/45e4e636b757/src/share/classes/java/net/InetAddress.java#l748)
+    - `JDK 9`的[`InetAddress`](https://hg.openjdk.java.net/jdk9/jdk9/jdk/file/65464a307408/src/java.base/share/classes/java/net/InetAddress.java#l783)
+    - `JDK 11`的[`InetAddress`](https://hg.openjdk.java.net/jdk/jdk11/file/1ddf9a99e4ad/src/java.base/share/classes/java/net/InetAddress.java#l787)
 - [`JVM Networking Properties` - `java docs`](http://docs.oracle.com/javase/8/docs/technotes/guides/net/properties.html)
 - [`java dns`解析缓存之源码解析](http://rongmayisheng.com/?p=1006)，写得很完整，源码解析。给出值得注意的结论：
     - 打开`Java`中的`SecurityManager`，`DNS`缓存将不会失效。

library/src/main/java/com/alibaba/dcm/internal/IPAddressUtil.java

@@ -1,10 +1,35 @@
+/*
+ * Copyright (c) 2004, 2015, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
 package com.alibaba.dcm.internal;
 
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 //
-// this source code file is copied from jdk sun.net.util.IPAddressUtil,
-// remove unused members.
+// This source code file is copied from jdk 11 and remove unused members:
+//
+// https://hg.openjdk.java.net/jdk/jdk11/file/1ddf9a99e4ad/src/java.base/share/classes/sun/net/util/IPAddressUtil.java
 //
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 

library/src/main/java/com/alibaba/dcm/internal/InetAddressCacheUtilForJava8Minus.java

@@ -63,11 +63,11 @@ private static Object newCacheEntry(String host, String[] ips, long expiration)
         // - for jdk 6, constructor signature is CacheEntry(Object address, long expiration)
         // - for jdk 7+, constructor signature is CacheEntry(InetAddress[] addresses, long expiration)
         // code in jdk 6:
-        //   http://hg.openjdk.java.net/jdk6/jdk6/jdk/file/tip/src/share/classes/java/net/InetAddress.java#l739
+        //   https://hg.openjdk.java.net/jdk6/jdk6/jdk/file/8deef18bb749/src/share/classes/java/net/InetAddress.java#l739
         // code in jdk 7:
-        //   http://hg.openjdk.java.net/jdk7u/jdk7u/jdk/file/tip/src/share/classes/java/net/InetAddress.java#l742
+        //   https://hg.openjdk.java.net/jdk7u/jdk7u/jdk/file/4dd5e486620d/src/share/classes/java/net/InetAddress.java#l742
         // code in jdk 8:
-        //   http://hg.openjdk.java.net/jdk8u/jdk8u/jdk/file/tip/src/share/classes/java/net/InetAddress.java#l748
+        //   https://hg.openjdk.java.net/jdk8u/jdk8u/jdk/file/45e4e636b757/src/share/classes/java/net/InetAddress.java#l748
         Constructor<?> constructor = clazz.getDeclaredConstructors()[0];
         constructor.setAccessible(true);
         return constructor.newInstance(toInetAddressArray(host, ips), expiration);
@@ -214,11 +214,11 @@ private static List<DnsCacheEntry> convert(Map<String, Object> cache) throws Ill
                     // - for jdk 6, address and expiration
                     // - for jdk 7+, addresses(*renamed* from 6!) and expiration
                     // code in jdk 6:
-                    //   http://hg.openjdk.java.net/jdk6/jdk6/jdk/file/tip/src/share/classes/java/net/InetAddress.java#l739
+                    //   https://hg.openjdk.java.net/jdk6/jdk6/jdk/file/8deef18bb749/src/share/classes/java/net/InetAddress.java#l739
                     // code in jdk 7:
-                    //   http://hg.openjdk.java.net/jdk7u/jdk7u/jdk/file/tip/src/share/classes/java/net/InetAddress.java#l742
+                    //   https://hg.openjdk.java.net/jdk7u/jdk7u/jdk/file/4dd5e486620d/src/share/classes/java/net/InetAddress.java#l742
                     // code in jdk 8:
-                    //   http://hg.openjdk.java.net/jdk8u/jdk8u/jdk/file/tip/src/share/classes/java/net/InetAddress.java#l748
+                    //   https://hg.openjdk.java.net/jdk8u/jdk8u/jdk/file/45e4e636b757/src/share/classes/java/net/InetAddress.java#l748
                     final Field[] fields = cacheEntryClass.getDeclaredFields();
                     for (Field field : fields) {
                         final String name = field.getName();

library/src/main/java/com/alibaba/dcm/internal/InetAddressCacheUtilForJava9Plus.java

@@ -52,9 +52,11 @@ private static Object newCachedAddresses(String host, String[] ips, long expirat
             throws ClassNotFoundException, UnknownHostException, IllegalAccessException, InvocationTargetException, InstantiationException {
         Class<?> clazz = Class.forName(inetAddress$CachedAddresses_ClassName);
         // InetAddress.CachedAddresses has only a constructor:
-        // - for jdk 9-jdk12, constructor signature is  CachedAddresses(String host, InetAddress[] inetAddresses, long expiryTime)
-        // code in jdk 9-jdk12:
-        //  http://hg.openjdk.java.net/jdk9/jdk9/jdk/file/65464a307408/src/java.base/share/classes/java/net/InetAddress.java#783
+        // - for jdk 9-jdk12, constructor signature is CachedAddresses(String host, InetAddress[] inetAddresses, long expiryTime)
+        // code in jdk 9:
+        //   https://hg.openjdk.java.net/jdk9/jdk9/jdk/file/65464a307408/src/java.base/share/classes/java/net/InetAddress.java#l783
+        // code in jdk 11:
+        //   https://hg.openjdk.java.net/jdk/jdk11/file/1ddf9a99e4ad/src/java.base/share/classes/java/net/InetAddress.java#l787
         Constructor<?> constructor = clazz.getDeclaredConstructors()[0];
         constructor.setAccessible(true);
         return constructor.newInstance(host, toInetAddressArray(host, ips), expiration);

library/src/main/java/com/alibaba/dcm/internal/IpParserUtil.java

@@ -34,7 +34,6 @@ static byte[] ip2ByteArray(String ip) {
             address = IPAddressUtil.textToNumericFormatV6(ip);
             if (address != null) return address;
 
-
             if (ipv6Expected) {
                 throw new IllegalArgumentException(ip + INVALID_IPV_6_ADDRESS);
             } else {

library/src/main/java/com/alibaba/dcm/internal/JavaVersion.java

@@ -16,14 +16,16 @@
  */
 package com.alibaba.dcm.internal;
 
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 //
-// this source code file is copied and small adopted from commons-lang-3.12.0:
+// This source code file is copied and small adopted from commons-lang-3.12.0:
 //
 // https://github.com/apache/commons-lang/blob/rel/commons-lang-3.12.0/src/main/java/org/apache/commons/lang3/JavaVersion.java
 //
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
+
 /**
  * <p>An enum representing all the versions of the Java specification.
  * This is intended to mirror available values from the

library/src/main/java/com/alibaba/dcm/internal/JavaVersionUtil.java

@@ -10,14 +10,16 @@ public static boolean isJdkAtMost8() {
         return JAVA_SPECIFICATION_VERSION_AS_ENUM.atMost(JavaVersion.JAVA_1_8);
     }
 
+
     ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     //
-    // blow source code is copied from commons-lang-3.12.0:
+    // Blow source code is copied from commons-lang-3.12.0:
     //
     // https://github.com/apache/commons-lang/blob/rel/commons-lang-3.12.0/src/main/java/org/apache/commons/lang3/SystemUtils.java
     //
     ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
+
     private static final String JAVA_SPECIFICATION_VERSION = getSystemProperty("java.specification.version");
     private static final JavaVersion JAVA_SPECIFICATION_VERSION_AS_ENUM = JavaVersion.get(JAVA_SPECIFICATION_VERSION);